12_clarification-02.pdf

EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. A

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

SG_Mech

Ch 2 : Project Information/Vol-II

1.0. 1.11)

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MSL of 64.5m is considered for boiler design as mentioned in the tender Station Graded Level Elevation from Mean sea level (MSL) The Contour map for the entire project land is enclosed in Volume- document "Vol-VII-TD-Layouts". Bidder request SJVN/Desein to confirm the same. VII. The Bidder shall accommodate equipment offered under this specification generally within the spaces allocated for such equipment in the Plot Plan Appendix – II: Coal Quality Parameters Ulitmate Analysis:

Confirmed.

1. Moisture content specified under proximate analysis seems to be on lower side compared to Indian coals. SJVN/Desein to check and confirm. 2. Sum of constituents specified under ultimate analysis is not equal to 100%. SJVN/Desein to check.

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Ch 2 : Project Information/Vol-II

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3. Bidder understand that provided ultimate analysis is dry ash free basis. Since the coal analysis is the basic input for boiler design, Bidder requests SJVN/Desein to provide coal analysis (proximate/ultimate) in AS RECEIVED basis.

Revised Coal Analysis shall be provided through ammendements.

4. Arsenic in coal has not specified in the given coal analysis, same required for the design/selection of Steam generator & Auxiliary equipment. 5. Clorine in coal has not specified in the given coal analysis, same required for the design/selection of Steam generator & Auxiliary equipment.

Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

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Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

3.1, vii)

SCR Efficiency for Control of NOx emission Contractor shall guarantee and demonstrate that at the end of 16000 hrs of operation and with the originally installed catalyst (i.e. without the use of future layer of catalyst) the SCR efficiency for 6 of 78 control of NOx emission (from thermal as well as fuel) shall not be less than 80% at 6% oxygen (O2) content in flue gas on dry gas basis and ammonia slip not exceeding 3ppm at 100% TMCR load condition, when firing any coal from the range of coal(s) specified.

3.1, viii)

Catalyst Life Contractor shall guarantee and demonstrate minimum SCR catalyst life of 16000hrs. The catalyst shall be deemed to have 6 of 78 exhausted its life as and when SCR/ Hybrid (SCR+SNCR) efficiency for control of NOx emission reaches to a level of 70%, with ammonia slip not exceeding 3ppm at 6% oxygen (O2) content in flue gas on dry gas basis.

There is a contradiction in ammonia slippage value among different clauses in the tender document. Hence bidder has considered ammonia slip not exceeding <3ppm in all the respective tender clauses. SJVN/DESEIN to confirm the same.

The provision as per bidding specification shall prevail.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

Clause No.

Page no.

2.21.23, B), 9)

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3.1, vii)

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Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

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Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

Bid Specification Stipulation

2.21.23, B)

3.6, (ii)

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a) NOx at SCR Inlet (mg/Nm3 at 6% O2 on dry basis, keeping ammonia slip within the maximum limit) Actual but limited to Guarantee Point - 500mg/Nm3 Design Point - 500mg/Nm3 c. Unburnt fuel at all efficiency load at 105% & 100% TMCR load - 1.0 % (min) (iii) Loss due to unburnt carbon in ash at all loads - 1% (minimum) or the quoted value whichever is higher

2.1.7.1

3.7

5.19, (i)

Owner's Reply

Ammonia Slip after last catalyst layer (ppm at 6% O2 on dry basis) Guarantee Point & Design Point = <2 ppm

SCR Efficiency for Control of NOx emission Contractor shall guarantee and demonstrate that at the end of 16000 hrs of operation and with the originally installed catalyst (i.e. without the use of future layer of catalyst) the SCR efficiency for control of NOx emission (from thermal as well as fuel) shall not be 6 of 78 less than 80% at 6% oxygen (O2) content in flue gas on dry gas basis and ammonia slip not exceeding 3ppm at 100% TMCR load condition, when firing any coal from the range of coal(s) specified.

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Statement of Prebid Queries & Clarification

Bidder would like to consider following points for catalyst design. 1. Actual NOx predicted by the bidder at SCR inlet shall be considered instead of 500mg/Nm3. 2. As per MOEF guideline, SCR outlet NOx of 100mg/Nm3 shall be considered instead of considering 80% efficiency for catalyst design. Hence bidder request SJVN/DESEIN to remove the NOx efficiency guarantee of 80% and SCR inlet NOx limit of 500mg/Nm3. The provision as per bidding specification shall prevail.

Loss due to unburnt carbon shall be as per bidder predicted value instead of 1%(minimum). Kindly confirm the same. Further bidder requests to keep the description of the cl.no 3.6, (ii) same as cl.no 2.1.7.1, in order to avoid different interpretation by various bidders.

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MAJOR REQUIREMNTS/ METHOD OF STEAM GENERATOR EFFICIENCY TESTS n) The Steam Generator efficiency testing shall be carried out with 15 of 78 any combination of mills in operation to Employer’s choice, with fineness of pulverized coal not exceeding 70% through 200 mesh. Coal Pulveriser capacity at rated fineness GUARANTEES UNDER CATEGORY-III 31 of 78 Rated pulverised coal fineness - a) not less than 70% through 200 mesh

The provision as per bidding specification shall prevail. The minimum value shall be 1% or more as applicable for calculation of Boiler efficiency.

Discrepancy is observed in coal fineness value among different clauses in the tender document. Bidder has considered coal fineness of 70% through 200 mesh for pulveriser selection and for performance guarantee test. Kindly confirm. Agreed. Read as 70% through 200 mesh.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

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Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

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Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

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Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

Ch 8 : Functional Guarantee & Liquidated Damages/Vol-II

Clause No.

Page no.

2.10.5.2, 3)

Sizing of Coal Pulverisers c) Rated Pulverized coal fineness* at rated capacity of the 37 of 120 pulverizer, not less than - 75% thru 200 mesh (75 microns) and 99% thru 50 mesh (300 microns)

4.1.1

5.4

5.5

5.11

10 Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.1.8

Bid Specification Stipulation

NOx emission Contractor shall guarantee that maximum total NOx emission from the unit shall not be more than 100 grams of NOx (from thermal as 26 of 78 well as fuel) per giga joule of heat input (at 6% O2 level and as per equivalent NO2) to the boiler during the entire operating range of steam generator for the range of coals specified. Steam temperature imbalance It shall be demonstrated at SH and RH outlets (in case of more 27 of 78 than one outlet) that the temperature imbalance between the outlets does not exceed 100 C under all load conditions.

Statement of Prebid Queries & Clarification

As per MOEF guide line NOx emission from the SCR outlet shall 100mg/Nm3 (at 6% O2 dry) instead of 100 grams per giga joule of heat input. Agreed. Read as 100 SJVN/DESEIN to amend the tender accordingly. 3 mg/Nm (at 6% O2 dry.) Bidder request SJVN/DESEIN to correct the clause as follows "It shall be demonstrated at SH and RH outlets (in case of more than one outlet) that the Agreed. temperature imbalance between the outlets does not exceed 10 °C under all ( Read as 10 degree C in load conditions." place of 100 degree C)

As per bidder standard practice and general industry practice Superheater SH and RH tube metal temperature It shall be demonstrated that superheater and reheater tube metal and Reheater tube metal temperature will be measured and will not be temperature at critical locations remain within maximum tube metal guaranteed. Kindly confirm acceptance. 27 of 78 temperature limits as per design of the OEM under various load conditions (i.e. 100%, 80%, 60% & 50%). No fuel oil support shall be required above 35% BMCR Contractor shall guarantee that oil support for flame stabilization shall not be required beyond 35% of BMCR load when firing the coals from the range identified. The Contractor shall demonstrate that with any combination of mills/ adjacent mills in service (to 29 of 78 Employer's choice) the Steam Generator does not require any oil firing for stable and efficient boiler operation at and above 35% BMCR loads.

Minimum Load without Oil Support for Flame Stabilization The design of Steam Generator shall be such that it does not call for any oil support for flame stabilization beyond 40% BMCR load 4 of 120 while firing any coal from the range specified, with any combination of mills / adjacent mills (to Employer's choice) in service.

Owner's Reply

The provision as per bidding specification shall prevail. It is not under guarantee but under demonstration.

There is a contradiction in minimum load without oil support for flame stabilization in different clauses of the tender document. Bidder has considered no fuel oil support above 40%BMCR. SJVN/DESEIN to confirm.

Read as 35% BMCR is minimum load for no fuel oil support for guarantee parameter.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Ch 6 : Erection Conditions of Contract/Vol-II

Clause No.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

vii. Min. load without oil support 40% BMCR with any range of coal specified 2.3.1, 12)

13.1

11

Ch 26 : Power Cycle Piping, Valves, Fittings & Thermal Insulation/Vol-III

Page no.

26.14.3

14 of 120 In case of equipment other than steam turbine, Lugs made out of MS rods of 5mm dia conforming to IS 280 or equivalent shall be welded on the surface at intervals of 250mm pitch zigzag to support insulation. Mineral wool mats with wire netting on both sides shall be applied against the surface with lugs piercing through. The edges of mattress shall be laced together with 6 of 48 galvanized MS 0.71mm dia (22 SWG) IS 280 or equivalent (soft) lacing wire. Galvanized binding wire of 1.63 mm dia (16 SWG) IS 280 or equivalent (soft) will be used criss-cross between lugs to hold it. The lugs will then be bent over the netting.

Wires of two different diameters (SWG) had been specified in these clauses. As a standard practice, we may use the clause no.26.14.3 for binding and lacing wires. Kindly confirm the same.

Confirmed.

b) Binding & lacing wire Galvanized steel wire to IS:280 for temperature below 400°C and stainless to IS:6528 for temperature above 400°C. 23 of 26 ---20 SWG for all insulation interface temperature

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

1.1.3

1.1.8.1

1.1.11.1

2.14.2, iii)

1.1.6.1, iv)

Page no.

Bid Specification Stipulation

Super heater(s) Superheater(s) including safety valves, main steam stop valves at superheater outlet with integral bypass valves, drains, start up 2 of 47 vents, air release valves, nitrogen connections, sampling connections, MTM thermocouples etc.

2.6

Owner's Reply

For once through supercritical units, boiler will be started with HP bypass valve in operation. Hence, start up vent valve is not necessary and not envisaged.

The provision as per bidding specification shall prevail (and for Re-heater if applicable).

x) All start-up vents, lowest set pressure spring loaded safety valve and electromatic relief valves at superheater & reheater outlet and 6 of 47 lowest set pressure spring loaded safety valves on Separator shall be provided with silencers for each safety valve. x) Start-up vent piping. 11 of 47 (b) Silencers on all start up vents (e) Start-up vents shall be sized for a minimum flow of 15% at 70 of 120 turbine start-up pressure. An alternate drain connection to enable start-up of steam generator even when the Start-up drain recirculation pump is not in service shall also be provided. The system shall comprise of an atmospheric flash tank and drain receiving vessel located in the Steam Generator area and shall be complete with all necessary valves, piping, level control system etc. The start-up drain from the separator(s)/ Drain collection vessel to atmospheric flash tank shall be led through twin piping leg, each leg being provided with a 3 of 47 motorized isolation valve and an Electro- hydraulic operated control valve. 2x50% pumps to transfer condensate from the receiving vessel to the main condenser shall also be provided. All necessary valves and discharge piping up to the condenser / flash tank in TG area will be in the Bidder's scope.

One (1) no. of condensate receiving vessel 1.1.12.1

Statement of Prebid Queries & Clarification

11 of 47 Boiler start-up recirculation & drain system shall be provided with start-up drain re-circulation pump and alternate drains to 18 of 120 Atmospheric flash tank. 2x50% condensate pumps shall be provided for pumping the flash tank condensate to turbine condenser.

Bidder has proven standard start up recirculation system and the boiler can be started with or without BCP in operation. With the bidder's standard start up system, in case of BCP is not in operation, drain water from WSDT shall be recovered to condenser directly through WDC valve during t start-up operation. This system has been followed in all our executed projects and working satisfactorily. Hence Bidder requests to accept above system. Further bidder would like to highlight that, there is a contradiction in number of condensate pumps provided in different tender clauses. SJVN/DESEIN to check and confirm. The provision as per bidding specification shall prevail. Regarding No. of Pumps : 3 Nos. of 50% shall be considered.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

Page no.

Bid Specification Stipulation

2.19, i)

BLOW DOWN SYSTEM 3x50% condensate transfer pumps located in Steam Generator 81 of 120 area and shall be complete with all necessary valves, piping, level control system etc.

2.19, iv)

BLOW DOWN SYSTEM 3x50% condensate transfer pumps to be provided. For arriving the 81 of 120 size of pump all drains as indicated in clause 2.19.0 (ii) shall be considered. As per bidder's practice, one no. quick acting motor operated block valve will be provided at common superheater attemperation line.

As per bidder's practice, one no. quick acting pneumatic operated block valve will be provided at common reheater attemperation line. The provision as per bidding specification shall prevail.

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15

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.7.3

Each leg of reheater desuperheating spray water system shall be provided with the following: 4 of 47 vi) A pneumatically operated quick acting block valve (with solenoid) in common RH attemperation line and upstream of each Reheater spray control station.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.8.1

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Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

vii) Electromatic Relief Valves (ERV) on SH outlet and RH outlet.

2.14.2

1.1.12.1

Owner's Reply

Each leg of each stage of desuperheating spray system for superheater shall be provided with the following: v) Quick acting pneumatically operated block valve (with DC 4 of 47 solenoid) at upstream of each superheater spray control station in the common super heater attemperation line.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.7.2

Statement of Prebid Queries & Clarification

The provision as per bidding specification shall prevail.

Safety valve and ERVs at SH/RH outlet shall be provided inline with ASME/IBR guidelines including the combined relieving capacity.

i) Safety valves and relief valves shall have minimum discharge capacities as under: a) Spring loaded safety valves 1. Separator & Superheater - Combined capacity105% BMCR. 2. Reheater System - Combined capacity 105% of reheater flow at 69 of 120 BMCR b) Electromatic Relief Valve at: 1. Super heater outlet - 15 %BMCR 2. Reheater outlet - 20% of Reheat flow at BMCR

Inline with ASME guidelines for once through boilers Electromatic relief valves are only provided at SH outlet and ERV at RH outlet is not envisaged.

One (1) no. of condensate receiving vessel and SCPAH drain collection tank(s)(located in SG area), including level gauges, redundant level transmitters for remote level control through SG 11 of 47 C&I systems, control valves, vents, drains etc.

As per bidder standard condensate from SCPAH will be directly sent to boiler flash tank through steam trap. Hence SCAPH condensate collection tank is not required.

In addition to the code requirement,the provision as per bidding specification shall prevail.

The provision as per

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume

Clause No.

17 Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.9.2, ii)

1.1.14.1

2.9.1, v), 5)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

The provision as per bidding specification shall prevail.

Steam Coil Air Preheaters (SCAPH) Condensate from SCAPH shall be led to atmospheric flash tank through SCAPH drain collection tank(s). SCAPH condensate collection tank(s) shall be pressurized so that drain can go to 32 of 120 Atmospheric flash tank. Alternatively Atmospheric SCAPH drain collection tank(s) with proper pumping arrangement (3x50%) with necessary valves etc. shall be provided. ii) One (1x100%) Independent air motor drive with independent / 13 of 47 common gear box with automatic clutching/declutching arrangement.

As per RAPH vendor's proven design, Common Gear box shall be provided for AC Motor and air motor with automatic clutching/declutching arrangement in line with cl.no 1.1.14.1.

ii) 1x100% independent air motor drive, with its gear box and automatic clutching, declutching facility for rotation during non30 of 120 availability of A.C drive system. vi) Permanent firefighting equipment on both gas as well as airsides and also on both cold as well as hot end sides including, spray nozzles, valves and pipe work connected to fire water system.

Agreed.

Firefighting equipment shall be provided on Hot end side only as the propagation of the flame towards cold end is not practical. Also Propagation of flame due to fire inside the heater will be basically more in air side, due to the availability of O2. The deluge of water supplied for the manifold at hot The provision as per end will flood the entire heater, which will prevent entire heater from catching bidding specification shall fire. Providing additional firefighting manifold at Cold end side are of no prevail. purpose, since this cannot spray & flood the heater as like the manifold at the top. SJVN/DESEIN to confirm.

1.1.14.1

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1.1.14.1

xii) Forced lubrication system for bearing of each air heater shall Type of lubrication for RAPH will be sump type lubrication as per OEM be provided and shall include two (2) x 100% capacity oil pumps standard 14 of 47 with motor, two (2) x 100% oil coolers, two (2) x 100% oil filters etc.

1.1.15.1

1.1.15.3, i)

2.3.1

ii) Manually operated rod type isolating gate at bunker outlet. Motor operated (sliding gate type) Raw Coal Bunker shut off gate at the 15 of 47 bunker mouth and manually operated gate at RC feeder inlet (both shall be for each coal feeder).

Owner's Reply

Bidder is considering motor operated sliding gate at bunker outlet and manually operated gate at coal feeder inlet, hence manually operated rod type isolating gate at bunker outlet is not required and not envisaged. SJVN/DESEIN to confirm the same.

Agreed.

The provision as per bidding specification shall prevail.

Minimum Eight (8) no’s of coal pulverizers shall be provided for 16 of 47 each steam generator.

12 of 120

Bidder is offering supercritical boilers with Twin fire vortex. In these boilers, one mill serves eight (8) burners at one elevation which results in significant reduction in heat input per burner. In this scenario, criteria of minimum Minimum number of coal pulverisers to be provided for each steam number of mills may easily be dispensed with, while leaving to the bidder to generator shall not be less than eight (8). select the number of mills based on mill operating requirements. Moreover, CEA also specifies 6 nos. mills as minimum for 660 MW unit and recent NTPC tenders also calls for less number of mills

The provision as per

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume

Clause No.

Page no.

Sizing of Coal Pulverisers Number of mills for Steam Generator - Adequate to achieve 100% TMCR for all specified coal(s) and all operating conditions but not less than eight (8) mills.

22 Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII 23

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Bid Specification Stipulation

2.10.5.2, 1)

1.1.15.10

37 of 120

2.10.5.19

For pulverized coal sampling for fineness and distribution: iii) Provide (a) Rota Probe for coal sampling as per ISO 9931 and ASME 40 of 120 respectively.

1.1.15.12

On line fuel measurement facility for accurate measurement of coal mass flow rate/ air fuel ratio in each pulverized fuel (PF) pipe for each coal pulverizer. The equipment shall comprise of sensors working on micro wave technology. The error in measuring system shall not be more than 5%, which shall be demonstrated by 19 of 47 comparisons with isokinetic measurements.

1.1.15.13

LMB has supplied 11 Units (700 MW & 660 MW) with front mill arrangement (6 mills) in which 8 units are in operation.

Owner's Reply p p bidding specification shall prevail.

Further with less number of mills and front mill arrangement total project cost as well as O&M cost shall be reduced.

Rota probe type coal sampling system for obtaining samples from Rota Probe for coal sampling as per ISO 9931 will be provided. PF outlets of all the mills using the methods specified in ISO 9931 18 of 47 "Coal sampling of pulverized coal conveyed by gases in direct fired coal system".

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Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Statement of Prebid Queries & Clarification recent NTPC tenders also calls for less number of mills

Adjustable valve/orifice of erosion resistant/ceramic coated material suitable for highly abrasive pulverised coal applications. The adjustable 19 of 47 valve/orifice shall be provided on each PF pipe at pulverizer outlets and shall enable on load adjustment of coal flow in PF pipelines.

Agreed.

On-line adjustment for equalizing the flow through the coal pipes is not feasible as reliable adjustable orifices are not available. Accordingly, fixed ceramic-coated orifices are provided. The fixed orifices are selected to achieve the equalization in the fuel pipes based on design stage calculation. Since on-line adjustment for equalizing the fuel flow through pulverized coal pipes is not possible, on-line flow measurement does not provide any improvement. The reliability and capability of the measurement devices are also not known and the number of vendors is very limited. Hence measurement using microwave technology and variable orifice, etc., is not envisaged.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.16, v)

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.6

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Page no.

Bid Specification Stipulation

Flue gas duct from economizer outlet to each cyclone separator inlet, from each cyclone separator outlet to each SCR reactor inlet, from each SCR reactor outlet to each RAPH (Bisector or Trisector, as applicable) inlet ducts, SCR bypass ducts 2) SCR bypass duct i.e. Economizer to APH shall be provided for facilitating operation of unit without SCR in case of any emergency requirement. This shall also facilitate the online maintenance of 42 of 47 SCR system and associated equipment. 20 of 47

Statement of Prebid Queries & Clarification

Owner's Reply

SJVN/DESEIN to note that NOx emission level should be maintained for entire plant operation, for which the total flue gas should pass through the SCR reactor. Providing the SCR bypass will not serve the purpose of online maintenance of SCR system, considering very high flue gas temperature. Hence bidder request SJVN/DESEIN to relook into the requirement of providing SCR bypass duct.

3) SCR bypass duct i.e. Economizer to APH 1.13.7.1, vi)

43 of 47 SCR bypass duct

2.21.5

2.21.5

2.21.23, c)

1.1.16, v)

1.1.16, xi)

95 of 120

SCR Bypass duct is required. Hence, The provision as per bidding specification shall prevail.

12) Dampers and Gates i) Motor operated gas tight gates along with their drives shall be provided at inlet, outlet and bypass duct of the SCR system for 96 of 120 carrying out internal repair and maintenance of complete SCR system when the Steam Generator is on load.

117 of 120

4) SCR bypass duct capacity Flue gas flow corresponding to BMCR load with 25% excess air

Flue gas duct from economizer outlet to each cyclone separator 20 of 47 inlet, from each cyclone separator outlet to each SCR reactor inlet, Cyclone separator is not envisaged by bidder. Also in recent NTPC tender, there is no requirement of cyclone separator before SCR System. Kindly Economiser bypass ducting from economizer inlet/intermediate confirm the acceptance. position to cyclone separator inlet with gates and ash collection 20 of 47 hopper

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No.

Section / Part / Chapter / Volume

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

26

Clause No.

1.13.1

1.13.2

1.13.3

1.13.4

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.5

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.6, 1)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Selective Catalytic Reduction System (SCR) The contractor’s scope of supply include design, engineering, manufacture, supply, erection, commissioning and testing of complete mechanical, electrical, C&I and associated civil foundation and structural work for Selective Catalytic Reduction 41 of 47 (SCR) System along with ammonia unloading, storage and handling system, Cyclone Separators complete in all respects with all components and accessories etc., for two (02) number steam generators each as detailed in this specification.

Selective Catalytic Reduction System (SCR) The scope of supply identified for SCR System along with ammonia unloading, storage and handling system, Cyclone Separators here are minimum requirements and unless excluded 41 of 47 from the contractor’s scope as per Terminal points and Exclusions, .......................................... also be included in the scope of the contractor. Selective Catalytic Reduction System (SCR) SCR System along with ammonia injection system and cyclone 41 of 47 separators shall be individual for each unit. Selective Catalytic Reduction System (SCR) The scope of contractor for SCR System along with ammonia 41 of 47 unloading, storage and handling system, Cyclone Separators shall include all items as shown in tender drawing. Selective Catalytic Reduction System (SCR) The scope of supply and services for SCR System along with 41 of 47 ammonia unloading, storage and handling system, Cyclone Separators for each unit shall include all items indicated below but will not be limited to that. Selective Catalytic Reduction System (SCR) Flue gas from downstream of economizer shall be taken through two (02) independent streams. Each stream shall have one (01) number of cyclone separator and one (01) number of SCR 41 of 47 Reactor. Cyclone Separator shall be used to reduce inlet dust concentration at the inlet of SCR reactor. The provision of Cyclone

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Section / Part / Chapter / Volume

Clause No.

Page no.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.7.1, vi)

44 of 47

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

c) Isolation gates at inlet of each cyclone separator,

1.13.8

1.13.8

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.12.1, 3)

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.12.1, b)

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply separator is deleted..

Cyclone Separators i) Two (02) no’s of independently operated Cyclone Separators housed in independent casings shall be provided for each unit including outside shell, structural steel supports and frame work, stiffeners, bracings, access ladders, platforms, safety rails, 44 of 47 stairways, walk ways, access doors, insulation etc. One (01) cyclone separator shall be provided in each stream of flue gas duct from economizer outlet to SCR reactor inlet.

Cyclone Separators iii) Sampling ports for off-line measurement of ash concentration in 44 of 47 flue gas at the inlet and outlet of Cyclone separators. Fan Sizing Criteria ID Fans 55 of 120 60% BMCR LOAD( one stream operation) f) Pressure drop through Cyclone Separator - 50 mmWC or actual whichever is higher Fan Sizing Criteria ID Fans 56 of 120 50% BMCR flow 8) Pressure drop through Cyclone Separator - 50 mmWC or actual whichever is higher Cyclone Separator shall be provided in the flue gas duct between economizer and SCR reactor to reduce the dust burden.

2.21.2, 1)

2.21.2, 3), 9)

2.21.5, 1)

84 of 120

Integration with other systems a) The ash from cyclone separator b) The service air, instrument air, auxiliary steam, various types of 86 of 120 water required for the SCR system and cyclone separator shall be integrated as .............................. Exclusion. DUCTING SYSTEM The ducting system for the SCR system shall connect the steam 95 of 120 generator outlet (gas side economizer outlet) to the reactor through the cyclone separator

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Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Cyclone Separator 2.21.5, 13)

97 of 120

2.21.23, B), 6)

116 of 120

Inlet Dust Burden (g/Nm3 ) Guarantee Point & Design point - 35 OR Ash remaining after cyclone separator collection as per cl. no. 2.21.23, C, iii-3, whichever is higher.

Bidder would like to request that cyclone separator is not envisaged, Hence, Bidder requests SJVN/DESEIN to remove the inlet dust burden requirement.

The provision of Cyclone separator is deleted.

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Section / Part / Chapter / Volume

Clause No.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.16

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

28

29

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

30

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

31

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.7.1

2.13.1.11

2.21.5, 11, i)

1.1.16, xi) 1.13.7.1, vi)

2.21.5, 1)

1.1.16, xii2)

1.1.16, xiii)

Page no.

Bid Specification Stipulation

Ducting 20 of 47 x) Suitable metallic type expansion joints wherever necessary shall be installed. vi) Ducts and Dampers b) Flue gas ducting system shall be complete with adequately sized turning vanes, deflector plates, flow splitters, guide vanes 42 of 47 and all necessary gas flow control devices of suitable erosion resistant material, metallic type expansion joints, Expansion Joints i) Metallic type expansion joints suitable for the service conditions shall be provided. The expansion joint design shall conform to the 64 of 120 requirements of the EJMA Standards.

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder would like to use Non-Metallic Expansion Joints at inlet and outlet of following equipments, as per the practice to minimise the heavy reaction load transfer to equipment. 1) SCR 2) RAPH 3) PA, FD and ID fan 3) ESP 4) Mill 5) Chimney 6) Economiser outlet duct 7) Seal air and Scanner air fan

Agreed for Mettalic and Non- Mettalic both and the provision as per bidding specification shall prevail.

SJVN/DESEIN to confirm.

Expansion joints Metallic expansion joints and anchor points for the system shall be 96 of 120 selected by the contractor in line with such over-arching requirement of system design. Economiser bypass ducting from economizer inlet/intermediate 20 of 47 position to cyclone separator inlet with gates and ash collection hopper 4) Economizer bypass duct from economizer inlet/intermediate 43 of 47 position to SCR inlet duct

Bidder shall take the bypass ducting either at Economiser bypass or from any other alternate suitable location for maintaining flue gas temperature at SCR inlet.

Agreed.

DUCTING SYSTEM Flue Gas duct from economizer inlet / intermediate position to inlet duct of each SCR reactor (Economizer bypass duct to maintain 95 of 120 suitable flue gas temperature at SCR inlet for part load conditions). common air ducting at FD fan, PA fan, SAPH, PAPH (for Bi-sector type RAPH) or RAPH (Trisector type) outlets, as applicable and 20 of 47 common flue gas ducts at ESP inlet and outlet.

Bidder shall provide common duct at FD fan outlet and RAPH outlet, hence interconnecting duct at SCAPH outlet is not provided.

A suitable interconnecting header shall be provided downstream of the Economizer outlet before APHs (bisector/trisector) for equal 20 of 47 distribution of the Flue gas flow between the two Flue gas paths to APHs.

SJVN/DESEIN to note that outlet of economiser shall be provided with The provision as per common duct, thereafter the duct will be taken with two streams leading to each SCR and then to each RAPH. Hence common duct at RAPH inlet is not bidding specification shall prevail. required.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Clause No.

1.1.17.1, v)

32

33

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.13.2.1 & 2.13.2.4

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.1.17.1, v)

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.13.2.1 & 2.13.2.4

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.21.5, 12), i)

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Page no.

Bid Specification Stipulation

Fully gas tight, motor operated, gates at each hot air & cold air duct to the mills, before and after each ESP stream, before and after each ID fan, at inlet to each of RAPH on flue gas side, at 21 of 47 discharge of each PA fans, FD fans and at each economiser bypass duct. Fully gas tight, pneumatic operated, gates at each hot air & cold air duct to the mills. Power operated gas tight isolation dampers along with their drives shall be provided at all locations required for carrying out internal repair and maintenance of pulverizers, electrostatic precipitators and induced draft fans when the Steam Generator is on load. As a minimum following locations shall be provided with power operated 65 of 120 gas tight dampers/gates: i) In each hot air and cold air duct to each of the mills (pneumatically operated).

Owner's Reply

As per the tender clause 1.1.17.1, v) there is a requirement of two isolation gates (motor operated & pneumatic operated) to be provided at each hot air & cold air duct to the mills. As per general industry practice & bidder standard single isolation damper is sufficient at each hot air & cold air duct to the mills. Further Bidder would like to supply pneumatic operated flap type damper with 100% sealing in each hot air and cold air duct to each of the mills instead of The provision as per gate. bidding specification shall prevail.

Bidder proposes motor operated double louver damper at Fully gas tight, motor operated, gates at 21 of 47 …………………………………………….…..and at each economiser Economiser/Superheater by pass duct for isolation purpose. Guillotine gate at this location is not possible due to layout constraint. bypass duct. Power operated gas tight isolation dampers along with their drives shall be provided at all locations required for carrying out internal repair and maintenance of pulverizers, electrostatic precipitators 65 of 120 and induced draft fans when the Steam Generator is on load. As a minimum following locations shall be provided with power operated gas tight dampers/gates: viii) At each economizer by pass duct Dampers and Gates Pneumatic operated control damper and motor operated gate shall 96 of 120 be provided in economizer bypass duct for regulation and isolation of economizer bypass flow. Fully gas tight, motor operated, gates at…………………………………………………., at inlet to each of RAPH on flue gas side

1.1.17.1, v)

Statement of Prebid Queries & Clarification

Agreed.

SCR bypass duct and cyclone separator is not envisaged by the bidder, Hence guillotine Gate at SCR inlet, SCR outlet & SCR bypass outlet shall not be considered.

21 of 47 Bidder proposes one no. double louver damper at RAPH inlet on flue gas side for each stream due to layout constraints and the same has been followed in all our executed projects.

1.13.7.1, vi)

c) Isolation gates at inlet of each cyclone separator, SCR outlet and SCR bypass duct of each SCR reactor and isolation gate & 44 of 47 control damper in economizer bypass duct to each SCR inlet duct.

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Section / Part / Chapter / Volume

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

2.13.2.1 & 2.13.2.4

2.21.5, 12), i)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Power operated gas tight isolation dampers along with their drives shall be provided at all locations required for carrying out internal repair and maintenance of pulverizers, electrostatic precipitators and induced draft fans when the Steam Generator is on load. As a minimum following locations shall be provided with power operated 65 of 120 gas tight dampers/gates: iv) At inlet to each of the Regenerative Air Pre-Heaters on flue gas side. viii) At ..........................Each SCR inlet duct, each SCR outlet duct (only incase of Bi-sector APH) & each SCR bypass duct.

Owner's Reply

The provision of cyclone separator is deleted and other provision as per bidding specification shall prevail.

Dampers and Gates Motor operated gas tight gates along with their drives shall be provided at inlet, outlet and bypass duct of the SCR system for 96 of 120 carrying out internal repair and maintenance of complete SCR system when the Steam Generator is on load.

Bidder to consider 2 no. of dampers at inlet of RAPH (Flue gas Volume VII-Tender Dwg no. 111-11side). One is Biplane multi louver with 2x100% seal air fan 15 of 63 Drawings -Mechanical 1200 arrangement, and one more guillotine damper for isolation purpose.

Section-1 Scope/Ch1 SG & Auxiliaries/Vol-III

1.1.22.1

35

Bidder shall follow the design criteria specified under cl.no. 1.1.22.1 for Refractories and insulation including cladding, lagging, thermal insulation of boiler. reinforcement, wire mesh, cleats and supports for all the equipment, auxiliaries, ducting, dampers, piping and valves in the scope of this specification so as to ensure skin casing temperature 25 of 47 of any surface in Bidder’s scope is not more than 60 deg.C with ambient temperature of 40 deg.C and air velocity of surface air being 0.25 m/s when the boiler is operating at 100% BMCR. 1. Ambient Temperature:

Ch 26 : Power Cycle Piping, Valves, Fittings & Thermal Insulation/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII 36

26.14.1.1

building 18 of 26, 2. Surface velocity: 19 of 26

40°C for inside and 45°C for outside the main plant

The provision as per bidding specification shall prevail.Bidder to follow the insulation based on the location of the equipments.

0.5 m/s for inside 0.25 m/sec for outside the main

plant building

1.13.7.1

SCR Reactor and Auxiliary System iii) Each SCR reactor shall include, but not limited to the following: 42 of 47 a) Inlet and outlet hood with guide vanes

Discrepancy is observed in the outlet hood requirement in various sections of Technical specification. However SJVN/DESEIN to note that there is no outlet hoods in the proposed SCR reactor as per bidder's standard design practice. Agreed.

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Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

38

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

2.21.4, 1), iv)

1.13.7.1

1.13.7.1, iv)

2.21.4, 4)

2.21.4, 4)

2.21.4, 4)

2.21.4, 4)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

c) Suitable space for inlet and outlet hoods, flow straightener and straight length requirement for flow stratification shall be 88 of 120 considered. Online gas analyser for SOx & CO2 is not required to measure at SCR inlet & SCR Reactor and Auxiliary System j) Gas sampling system including online gas analysers at inlet and outlet and hence the same is not required to consider at this location. Agreed. 43 of 47 outlet of SCR reactor for measurement of NOx, SOx, O2, CO2 etc. SJVN/DESEIN to confirm. Catalyst De-dusting System a) Adequate number of Rake retractable type steam operated Soot blowers shall be provided for each catalyst layer (including future layer) complete with structural supporting frame, access platform, motors, piping, control & instrumentation, insulation etc. b) In addition to steam type soot blowers, bidder to provide 43 of 47 additional Sonic horns & Air Cannons for each catalyst layer (including future layer) complete with structural supporting frame, access platform, compressed air storage vessel, piping, control & instrumentation, insulation, acoustic enclosures etc.

Catalyst De-dusting System The catalyst de-dusting system shall use rake type steam soot blower. In addition to steam type soot blowing, sonic horn and air 92 of 120 cannon for blowing/dislodging accumulated/sticking ash and fouling on catalyst surface shall be provided. i) Rake type steam soot blowers a) Soot blowers shall be provided for cleaning all catalyst layers, 93 of 120 including the future layer. Adequate number of soot blowers shall be provided so that it should cover complete catalyst surface area.

Tender calls for Rake retractable type steam operated Soot blowers, Sonic horns & Air Cannons for Catalyst De-dusting. But as per general OEM practice either rake type steam soot blower or sonic horn and air cannon shall be used for Catalyst De-dusting. Bidder request SJVN/DESEIN to amend the clause accordingly.

Agreed.

ii) Sonic Horn a) Sonic horn shall be provided for cleaning all catalyst layers, 93 of 120 including the future layer. Adequate number of sonic horn shall be provided so that it should cover complete catalyst surface area. iii) Air Cannons a) Air cannons shall be provided for cleaning all catalyst layers, 94 of 120 including the future layer. Number of air cannons shall be provided so that it should cover complete catalyst surface area.

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Section / Part / Chapter / Volume Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

39

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

40

41

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

Clause No.

1.13.7.1

2.21.6

1.13.7.1, vii)

2.21.4, 3, xi)

1.13.10, ii)

1.13.10, ii)

Page no.

Bid Specification Stipulation

vii) CFD and Physical modeling a) Contractor’s scope shall include Computation Fluid Dynamics 44 of 47 (CFD) and Physical modelling for SCR reactor,

Statement of Prebid Queries & Clarification

Owner's Reply

Based on bidder experience and proven practice the requirement for physical model test is not envisaged. Therefore, bidder request confirmation to carry out CFD analysis only.

CFD and Physical Flow Modeling CFD modelling as well as physical modelling for SCR reactor, upstream duct work from economizer outlet (including economizer bypass) along with cyclone separator and downstream ductwork from SCR reactor outlet upto Air preheater inlet shall be carried out 97 of 120 to examine and finalize the design options for the duct system, flow modification devices, Ammonia Injection Grid (AIG), etc. Modeling shall be carried out with the following objectives:

The provision as per bidding specification shall prevail.

SCR slip stream pilot test is being conducted in NTPC operating plant. The b) Contractor’s scope shall also include conductance of laboratory/shop test to establish and demonstrate the activity of the test result / report shall be enough to fulfil the specification requirement and 44 of 47 catalyst selected for Indian coal/ash. Further, such test shall be no separate test is required. SJVN/DESEIN to confirm. conducted and report shall be provided to customer before supply of catalyst to site. Catalyst modules The design of the catalysts shall consider coal ash, typical poisons, SO2 and SO3 content of the flue gas. Bidder shall collect typical Indian coals to test them for identifying potential poisons and reactivity profile for the catalyst composition selected for the project. The catalyst shall be suitable for cleaning by specified 91 of 120 catalyst dedusting devices. The design of the catalysts shall take into account the minimization of the effects and impact of the operation of the NOx reduction system on downstream plant components, specifically air preheater.

h) A dyke shall be provided around storage tank area with storage capacity equivalent to one storage tank, for collection of liquid 45 of 47 ammonia in case of emergency. This dyke shall be connected to waste water retaining basin.

LMB understand that dyke capacity equivalent to one storage tank is common for two storage tanks. Please confirm.

d) Three (03) no’s Ammonia vaporizer and associated systems. Each ammonia vaporizer shall be capable of vaporizing the 45 of 47 ammonia to meet the requirements of SCR system of one unit.

Considering the constraints in the controllability and backup operation of the Ammonia for two boilers with three set of Vaporizer and Accumulator (Two working and One standby), Bidder insists SJVN/DESEIN to consider one set of Vaporizer and Accumulator for One boiler (Totally Two working and no standby).

The provision as per bidding specification shall prevail.

Confirmed.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

1.13.10, ii)

45 of 47

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 1 : Scope/Ch 1: SG & Auxiliaries/VolIII

43

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.21.9, 5), a)

106 of 120

2.21.23, D), iii)

118 of 120

2.21.23, D), iv), b)

119 of 120

1.13.10, ii)

Bid Specification Stipulation

106 of 120

2.21.9, 5), c)

107 of 120

2.21.9, 5), e)

107 of 120

Owner's Reply

e) Three (03) no’s ammonia accumulators and associated systems. Each ammonia accumulator shall be capable of handling the ammonia to meet the requirements of SCR system of one unit. Ammonia Vaporizer Three (03) common ammonia Vaporizer shall be provided for all the two (02) steam generators. Vaporizer shall be designed to supply ammonia vapour to SCR reactor under all operating conditions. The vaporizer shall be shell and tube type heat exchangers.

The provision as per bidding specification shall prevail.

Ammonia vaporizer system 1) Total No. of vaporizer - Three (03)

Accumulators 1. No. of accumulators - Three (03)

f) 2x100% Glycol-water recirculation pumps with common water/ glycol heater for each ammonia vaporizer and common overhead 45 of 47 make up water/glycol tank. Make up shall be tapped from suction header interconnecting the Condensate storage tanks (CST)

2.21.9, 5), a)

Statement of Prebid Queries & Clarification

SJVN/DESEIN to note that the ammonia vaporiser for ammonia handling system shall be decided by ammonia handling vendor.

As per ammonia handling vendor information, the vaporiser will be filled with water. The water will be heated by steam at the bottom of vaporiser. The heated water will then heat the Ammonia at the top of the vaporiser. In this Ammonia Vaporizer type of vaporiser, there is no requirement of two separate heat exchangers Glycol/water cycle which in turn would supply heat to ammonia. and recirculation pumps as specified in the technical specification. Glycol/water mixture as intermediate heat transfer medium shall be A makeup DM water line shall be connected to the vaporiser with an isolation circulated in closed cycle. valve for makeup water.

Ammonia Vaporizer 2X100% capacity Glycol/water pump with 1X100% capacity glycol/water heater shall be provided for recirculation and heating of Glycol/water mixture for each ammonia vaporizer. Glycol/water will be heated through Auxiliary steam. Ammonia Vaporizer Changeover to standby glycol/water recirculation pump and standby vaporizer without interruption to service.

The provision as per bidding specification shall prevail.

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45

Section / Part / Chapter / Volume

Section 2 : Design Basis of SG & Auxiliaries and 2.21.23, D), 4) SCR/Ch 1: SG & Auxiliaries/Vol-III Section 1 : Scope/Ch 1: SG & Auxiliaries/Vol1.13.11 III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

46

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

47

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

48

Clause No.

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

2.1.10, i)

2.1.11

Page no.

Bid Specification Stipulation Water/Glycol heater

iii) Sheathing work for roof/ canopy/ side cladding of SCR system. 46 of 47 i. Hot start (after shut down period less than 10 hours) - 4550 ii. Warm start (after shut down period between 10 hours and 72 hours) - 1000 6 of 120 iii. Cold start (after shut down period exceeding 72 hours) - 455

As per OEM practice, No side cladding/Roof sheeting is envisaged for SCR system. Kindly confirm the same.

8 of 120

Alloy steel ASME SA-335:P-92/T-92 or approved equivalent.

10 of 120

The provision as per bidding specification shall prevail.

Bidder's proposal for number of start-up is as follows, i. Hot start (after shut down period less than 10 hours) - 4000 ii. Warm start (after shut down period between 10 hours and 72 hours) - 1000 The provision as per bidding specification shall iii. Cold start (after shut down period exceeding 72 hours) - 150 prevail.

Kindly note that the operation with all HP heater out condition, the heat Operation without High Pressure (HP) Heaters in service Steam generator shall be capable of operation with HP heaters out output may be limited to 100%TMCR heat duty instead of 100% BMCR heat duty. of operation. The steam generator heat output under HP heaters out condition shall be at least 100% BMCR heat duty. Steam generator shall also capable of sustained operation with HP 6 of 120 heaters out of operation so as to generate at least rated power output by the unit.

Noise level i) Safety valves and associated vent pipes for which it shall not exceed 105 dBA. 2.1.20

Owner's Reply

118 of 120

Upto & including 610 degree Celsius (*) 2.1.16

Statement of Prebid Queries & Clarification

The heat output shall meet 100% BMCR .The provision as per bidding specification shall prevail.

As per bidder standard ASME SA-213:T-92 material shall be used in terminal tubes (i.e. from header to coil at unheating zone) for ease of welding. Hence The provision as per SJVN/DESEIN to permit the use of ASME SA-213:T-92 material beyond bidding specification shall design metal temperature of 610°C in the nonheating zone. prevail. The sound level for safety valve (105dBA) shall be achieved with silencer. The sound level may exceed 105dBA for the safety valve without silencer. As per Cl.no 1.1.8.1 (refer Section-1, Ch-1, Vol-III), silencer shall be provided for lowest set pressure spring loaded safety valve and electromatic relief Agreed valves at superheater outlet, lowest set pressure spring loaded safety valves on Separator and lowest set pressure spring loaded safety valve at Reheater outlet

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Clause No.

2.1.22, ii)

2.1.22, iv)

2.5

2.2

2.7.4

2.8, iii)

2.3.1

Page no.

Bid Specification Stipulation

Further, design pressure of the Steam Generator pressure parts upstream of Separators shall be atleast 1.05 times the maximum operating pressure, or as required by IBR/ASME, or Pressure arrived based on lowest set pressure of spring loaded safety valve 10 of 120 on the separators plus the pressure drop from separator to the respective pressure part; whichever is higher.

Statement of Prebid Queries & Clarification As per bidders standard and general industry practice, design pressure shall be 1.05 times the maximum operating pressure of that part shall be considered. Also SJVN to note that, design pressure selection as per tender results in higher pressure drop across the furnace tubes, which has direct influence on increase in auxiliary power consumption.

The working fluid temperature to be considered for design of boiler Bidder shall consider Design temperature for pressure parts as per IBR. SJVN/DESEIN to confirm. tubes, headers, separators and other pressure parts upto first stage of attemperation shall be arrived by adding an additional margin of minimum 40 deg.C to the maximum predicted/expected 11 of 120 fluid temperature in these pressure parts or plus the margin as per IBR whichever is higher.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

STEAM SEPERATOR(S) b) Design Temperature - Maximum fluid temperature plus 40°C 17 of 120 (Min.) or max fluid temperature plus the margin as per IBR, whichever is higher. vii) In the Steam Generator enclosure, minimum 1.5 m cavity height shall be provided in between the horizontal banks/sections 12 of 120 of economizer, superheater and reheaters for maintenance purpose.

The Horizontal & Vertical cavity height in between the banks/ sections of economizer, superheater and reheaters shall be provided as per bidder standard only (1.2m approx).

Construction of Superheaters (s) & Reheater(s) shall have following features: For maintenance/inspection of SH/RH, provide: 24 of 120 i) 1.5 m clear cavity height between two sections/banks of horizontal heat transfer surfaces for personnel access from both the sides of the boiler. Economizers shall be provided with:a) Minimum 1.5 m clear cavity height between two sections/banks 26 of 120 of the economizer for maintenance access from both the sides of the boiler. FURNACE/EVAPORATORS AND WATER WALLS i) Pressure withstanding capability - ±660 mmwc (Minimum) at 12 of 120 67% yield strength or Maximum conceivable head of fans, whichever is higher

The provision as per bidding specification shall prevail.

There is a contradiction in tender document regarding duct design pressure selection. Based on bidder experience, All flue gas duct, air ducts, SCR reactors and the wind boxes shall also be designed for +/- 660mmWC at 67% of yield strength of material or maximum

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53

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Clause No.

2.13.1.3

2.21.4, 2)

2.3.1

Page no.

Bid Specification Stipulation

Duct Design Pressure All flue gas ducts, air ducts and the wind boxes shall also be 61 of 120 designed for ±660mmWC or maximum conceivable pressure of the relevant fans, whichever is higher, at 67% of yield strength of material. Reactor Housing Design iii) Design Pressure: The reactor shall be designed for ± 660 89 of 120 mmWC or maximum conceivable pressure of the relevant fans, whichever is higher, at 67% of yield strength of material used for reactor frame/stiffeners/plates. FURNACE/EVAPORATORS AND WATER WALLS l) Furnace Bottom hopper Design of Boiler and its supporting structure shall be considering 50% ash/clinker loading in furnace bottom hopper and corresponding to ash density of 1600 Kg/m3.Further load cells (16 12 of 120 min.no of load cells per boiler) shall be installed in the furnace roof enclosure to give indication of ash build up in the furnace bottom hopper.

Statement of Prebid Queries & Clarification g y g conceivable pressure of the relevant fans, whichever is higher. SJVN/DESEIN to confirm the same.

For Furnace Bottom hopper, the Ash density for the purpose of ash loading shall be 1350 kg/m^3 (similar to Ch 1: SG & Auxiliaries Section 2 : Design Basis of SG & Auxiliaries and SCR /Vol-III/Sheet | 17 of 120/ Clause 2.4). SJVN/DESEIN to confirm the same.

FURNACE/EVAPORATORS AND WATER WALLS A minimum allowance of 0.6 mm over and above the calculated thickness as per IBR shall be provided for entire water wall. An additional tube thickness of 1.0 mm over and above the tube thickness of water wall tubes calculated as per above shall be 13 of 120 provided on all water wall tubes coming within a radius of one meter around each wall blower to guard against premature tube failure due to soot blowing steam erosion.

A minimum allowance of 0.6 mm over and above the calculated thickness as per IBR shall be provided for entire water wall.

2.3.1, 7)

FURNACE/EVAPORATORS AND WATER WALLS Headers shall be located external to gas path and shall be 13 of 120 completely drainable. If locating headers in gas path becomes unavoidable, then suitable erosion shields must be provided.

Headers for economizer inlet/intermediate, primary SH inlet, RH inlet headers and 2ry gas pass inlet manifold are located within the gas path. No erosion shields are envisaged. However bidder will take suitable measure for erosion protection.

2.3.1, 16)

FURNACE/EVAPORATORS AND WATER WALLS Erosion resistant shields for tubes/header affected by gas 15 of 120 impingement/laning effects (Eg. in a between SH/RH, Economizer and furnace walls openings for economizer bypass etc.)

2.3.1, 4)

Owner's Reply

Confirmed.

Bidder to follow 1600 kg/m3 for furnance bottom hopper.The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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Clause No.

2.7.2

2.8, ii)

2.3.1, 15)

2.15.18

2.4, i)

2.7.1, 2)

Page no.

Bid Specification Stipulation

5. Arrangement of headers a) Located outside the gas path, fully drainable. Wherever, locating the headers in the gas path becomes unavoidable these shall be suitably protected with erosion shields. Further, the nipples and studs of the header shall also be provided with wear resistance 22 of 120 stainless steel shields of minimum 2.5 mm or higher thickness. The arrangement of headers shall be such that it does not cause the high localized flue gas velocity on tubes downstream side of the header.

Statement of Prebid Queries & Clarification

Owner's Reply

Agreed,

ECONOMISERS (h) Headers shall be located external to gas path and shall be 25 of 120 completely drainable. If locating headers in gas path becomes unavoidable, than suitable erosion shields must be provided. FURNACE/EVAPORATORS AND WATER WALLS Provision for future installation of additional Soot Blowers shall be 15 of 120 made in the furnace. The entire furnace should be covered by wall blowers so selected such that cleaning coverage per wall blower should not be more than 2m in diameter and there should be no left out portion. One 74 of 120 wall blower elevation below the lowest burner elevation shall also be provided.

Number of wall blower to be installed in the boiler shall be as per bidder's requirement. SJVN/DESEIN to note that due to intermediate header in the water wall and due to boiler nose formation by the rear wall, installation of the wall blower up to radiant superheater may not possible. Further based on bidder operating plant experience such additional wall blower requirement is The provision as per not necessary. bidding specification shall prevail.

b) The casing/pent house and its supporting system shall be capable of taking additional loads due to accumulations of ash upto 300 mm height or actual expected (in between two overhauls of the unit), whichever is higher. This additional load is over and 17 of 120 above other loads considered for casing design. The ash density for the purpose of ash loading shall be at least 1350 kg/m³.

Based on bidder experience and proven practice the accumulations of ash on the casing/pent house is not envisaged. Therefore, casing/pent house and its supporting system shall be allowed to be designed as per bidder's standard The provision as per practice considering no additional loads due to accumulations of ash. bidding specification shall SJVN/DESEIN to confirm the same. prevail.

Maximum average flue gas velocity in section/tube banks with transverse tube pitching 600 mm or less and with 25% excess air 21 of 120 at economizer outlet - 10 m/sec. (The maximum localized velocities across the cross- section shall not exceed 12 m/ sec.)

Bidder and its technology partner has experience of designing boiler considering 15% excess air at ECO outlet. However tender calls for minimum 20% excess air at TMCR condition. Hence 20% excess air shall be considered for meeting specified flue gas velocity at 100% BMCR instead of The provision as per 25% excess air. bidding specification shall

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Clause No.

2.8, 3)

2.7.2, g)

2.7.2, 3)

2.7.2, 4), a)

2.8, 4)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

bidding specification shall prevail.

Maximum average flue gas velocity through the Economizer tube banks, with 25% excess air at Economizer outlet. - 10 m/sec. (The 24 of 120 maximum localized velocities across the cross-section shall not exceed 12 m/sec) With any coal from specified range Construction of Superheaters (s) & Reheater(s) shall have following features: The first bank of coils in the second pass (in case of two pass 21 of 120 boiler) shall be located at least 2 meters below from the second pass gas entry zone to minimise erosion.

As per Bidder's experience, the entry level erosion is eliminated by providing SS protectors on leading tubes of horizontal coil banks. Hence the heating surface arrangement at second pass will be as per bidder standard.

Construction of Superheaters (s) & Reheater(s) shall have following features: Maximum depth of tube banks/sections in the direction of gas flow: 22 of 120 a)2 meters or maximum soot blowing radius, whichever is lower.

More heating surface area is required for the Steam Generator having 603 deg C SH & RH outlet steam temperature. To accommodate the more heating surface the horizontal SH & RH bank height shall be extended to 2.5 m instead of 2 m.

Construction of Superheaters (s) & Reheater(s) shall have following features: Supporting arrangement 22 of 120 One (1) mm erosion allowance shall be provided over and above the calculated thickness of hanger tubes.

Tubes shall be designed as per IBR and no additional erosion allowance is considered over and above the IBR requirements.

Economizer tube thickness (i) Provide erosion allowance of 1mm (minimum) in addition to 24 of 120 thickness calculated as per IBR formulae.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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Clause No.

2.7.2, 7)

2.7.2, 9)

2.7.2, 10)

2.8, iv)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Construction of Superheaters (s) & Reheater(s) shall have following features: Minimum tube thickness a) LEADING TUBES OF THE BANK: Provide 1.0 mm (min.) over and above the calculated thickness as per IBR (Ref. as specified at clause no 2.1.22 of this section) for erosion allowance. b) BALANCE OF TUBES IN THE BANK: Provide 0.6 mm (min.) over and above the calculated thickness as per IBR (Ref. as 22 of 120 specified at clause no 1.22 of this section) for erosion allowance. c) Minimum tube thickness at the bends in no case shall be less than the minimum tube thickness for the straight tubes calculated in the manner described at (a) and (b) above. For this purpose appropriate thinning allowance shall be considered by the Bidder while calculating the thickness of the bends

Bidder does not envisage the consideration of additional erosion allowance for the leading edges of the bank and other Balance of tubes: * SS erosion protectors are provided on leading tubes for the horizontal banks (1RY SH & 1RY RH) and also for those tubes facing the soot blowing steam. * Further, Anti short pass baffles are provided at the top and bottom of tube bends of horizontal banks to avoid gas bypassing between the coil bend and the walls. The provision as per * For thinning at bends, the thickness margin as per IBR shall be considered. bidding specification shall prevail.

Construction of Superheaters (s) & Reheater(s) shall have following features: 23 of 120 Max no. of material grades in flue gas path inside the boiler can be used in one bank:- Three (3)

Higher volume of heating surface area is required for the Steam Generator having 603 deg C SH & RH outlet steam temperature and accordingly wide The provision as per range of material need to be provided. Hence the number of material need to bidding specification shall be used in the bank shall be decided by the boiler manufactures. prevail.

Construction of Superheaters (s) & Reheater(s) shall have following features: Space Provision a) Keep provision of space for atleast 20% addition of additional economizer surfaces in future. Structure/hanger design shall be 23 of 120 suitable for loads due to these additional surfaces (filled with water) also. b) Additional space of atleast 5% for SH and RH coils area shall envisaged.

Bidder and their technology partner having vast experience in selecting the required heating surface for design of supercritical boilers. Hence space for installation of additional heating surface in future is not required.

The provision as per bidding specification shall prevail.

On gas inlet side of the Economizer, provision of space shall be kept for future addition of minimum 20% economizer surfaces. Structure/hangers design to be suitable for loads due to this 26 of 120 additional water filled surfaces also.

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Clause No.

2.7.4, iii)

2.9.1, v)

2.9.1, v)

2.9.1, v)

2.9.1, xi)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Stainless Steel Erosion shields for all bends of outer most tube/coil of all SH/RH sections and hanger tubes in areas where flue gas temperature is below FEGT. For the pendant tube sections, the 24 of 120 erosion shield on the leading tubes and wherever else considered necessary by the Bidder as per the proven design.

As per bidder standard, Stainless steel protection shield shall be provided on leading tubes of horizontal banks exclusive. Outermost bends of all SH/RH Sections are beneath the anti-short pass plate Agreed. and are not directly exposed to flue gas and as per Bidder's proven design doesn’t have this outermost bend SS erosion shields.

Regenerative Air Pre-Heaters (Trisector type RAPH) 1. Type Rotary, regenerative, (Ljungstrom or approved equivalent), counter flow with vertical axis of rotation, enclosed with air/gas tight casing. Two tiers of heating elements shall be provided. Heating element 29 of 120 profile shall be selected to enable easy removal of ammonium bisulphate and ash.

Requirement of two tiers is contradicting from the clause 2.9.1 v) 2.b, which is asking for Hot/ Intermediate End Tiers, which gives an impression of three tiers. SJVN/DESEIN to clarify. The provision as per bidding documents shall prevail.

Regenerative Air Pre-Heaters (Trisector type RAPH) 2. Heating Elements 29 of 120 a) Cold end b) Hot / Intermediate end Regenerative Air Pre-Heaters (Trisector type RAPH) 2. Heating Elements a) Cold end 29 of 120 Made of vitreous enameled steel with minimum 1.0 mm thick base and additional 0.15 mm enamel thickness on each side.

Owing to constraints in the manufacturing and the lead time, and for the current nature of the flue gas analysis, we would recommend base material to be made up of vitreous enamelled steel with minimum 0.75 mm thick base Confirmed. and additional 0.15 mm enamel thickness on each side. SJVN/DESEIN to confirm the same.

Regenerative Air Pre-Heaters (Trisector type RAPH) xi) Provide: a) Sufficient space provision for future installation of minimum additional 15% of APH heating surface area shall be made in the design so that, the same can be installed, if required. The bearings, supports, casings, drives for APHs etc. as well as APHs 30 of 120 supporting structures and foundation loads are designed to take care of all the requirements due to the above addition of heating surface. APH design shall enable easy modular installation of heating surfaces including 15% additional surface.

As per bidder's experience provision for future installation of minimum additional 15% of APH heating surface is not required, hence same is not envisaged.

The provision as per bidding specification shall prevail.

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Clause No.

Page no.

2.10.5.2, 3)

Sizing of Coal Pulverisers a) Maximum permissible mill loading for deciding mill capacity (selection of mill type/model) complying with requirement at clause 37 of 120 2.10.5 above - 85% or the mill loading achievable corresponding to the near worn out conditions of mill grinding rolls/balls/tyres etc. whichever is less. This condition shall be complied for the range of specified coals including the adequacy range of coals.

2.10.5.14

Bid Specification Stipulation

Statement of Prebid Queries & Clarification Mill loading of 85% will make bidder to select the larger capacity mill and the tender calls for margin on stand-by (Design coal BMCR (N+1), Worst Coal TMCR (N+1)) requirement also. Hence request SJVN to consider mill loading of 90% for mill selection. Further As per general industry guideline and as per CEA specification maximum permissible mill load is 90%.

Please note that the YGP index of the coal is not mentioned in the Minimum Guaranteed Life of Coal Pulverizer Wear Parts specification. Mill wear part life depends on the YGP index, Hence request a) Seals - 20000 hours customer to kindly provide the same for guarantee purpose. b) Grinding elements (Rolls/Balls and Rings/Race) - 8000 hours c) Mill discharge valves - 15000 hours d) Classifier cone and other items lined with Ceramic material 25000 hours 39 of 120 e) Classifier vane - 25000 hours i) The expected wear life of mill grinding elements (Rolls/Balls and Rings/Race) in equivalent hours, under conditions stipulated above shall be at least 8000 hours.

Ensure minimum mill turn-down ratio(s) of 4:1. 40 of 120

2.10.8.2, i)

(d) Air-heater air-in-leakage of 15% of flue gas flow entering in Tri-Sector Air heater leakage consideration for the PA fan design shall be in case of a Bi-sector APH (OR) 10% of flue gas flow entering in case line with the FD fan requirement "For Tri-sector APH, actual guaranteed 45 of 120 of a Tri-sector APH (OR) guaranteed whichever is higher. value of leakage will be considered for fan sizing."

2.10.8.2, ii)

2.11.3, iii),

The provision as per bidding specification shall prevail.

HGI report will be provided along with revised coal analysis report.

As per OEM standard mill turn down ratio shall be 3:1. If mill loading is less there will be huge noise due to metal to metal contact.

2.10.5.17

(d) Air-heater air-in-leakage of 15% of flue gas flow entering in case of a Bi-sector APH (OR) 10% of flue gas flow entering in case 45 of 120 of a Tri-sector APH (OR) guaranteed whichever is higher.

Owner's Reply

Agreed.

The provision as per bidding specification shall prevail.

(b) For all in line items on fuel oil lines like pumps, flow meters, Single isolation valve after pump discharge as per Tender P&ID 111-11-1301 filters, control valves etc., required to be taken out for shall be provided. maintenance, following shall be provided both upstream and downstream sides: 50 of 120 Agreed. (2) Double Isolation valves from discharge onwards of pressurizing pumps

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Clause No.

2.12.1, 3)

2.12.1, b)

2.12.1, 3)

2.12.1, b)

2.12.3

Page no.

Bid Specification Stipulation

Fan Sizing Criteria ID Fans 60% BMCR LOAD( one stream operation) 55 of 120 g) Pressure drop through SCR System - 150 mmWC or actual whichever is higher Fan Sizing Criteria ID Fans 56 of 120 50% BMCR flow 9) Pressure drop through SCR System - 150 mmWC or actual whichever is higher Fan Sizing Criteria ID Fans 55 of 120 60% BMCR LOAD( one stream operation) k) Pressure required at chimney inlet - + 40 mmWC

ID Fans (Axial type) Fan casing material thickness - Abrasion and wear resistant, high BHN steel having minimum 8mm thickness or 12mm mild steel 57 of 120 with liner of thickness 10mm (min.)

59 of 120

Owner's Reply

Pressure drop through SCR System specified in the tender document seems to be higher side, this results in bigger ID fan and efficiency at operating point will be less. Hence bidder shall consider the pressure drop across SCR as guaranteed by SCR supplier for ID fan sizing. The provision as per bidding specification shall prevail.

In case separate booster fan is provided for FGD system, ID fan shall be sized considering +10mmWC at chimney inlet. No booster fan envisaged. The provision as per bidding specification shall prevail.

Fan Sizing Criteria ID Fans 56 of 120 50% BMCR flow 13) Pressure required at chimney inlet - + 40 mmWC

Fan Casing i) The fan casing shall be split to provide easy removal of the fan hub/impeller for replacement and repairs 2.12.9

Statement of Prebid Queries & Clarification

Bidder shall consider the following for ID fan as per OEM standard. Diffuser: 8 mm (MS material) Impeller Casing: 22mm (MS material) Intermediate Piece: 8 mm (MS Material, if applicable) Inlet box: 8 mm (MS material - 200 BHN - abrasion and wear resistant) SJVN/DESEIN to confirm.

The provision as per bidding specification shall prevail.

As per OEM standard, fan design consists of rolling diffuser / inlet box for onsite maintenance, diffuser (in case of single stage and two stage fans) and inlet box (in case of two stage fans) are mounted on rails for ease maintenance of hubs and blades. AS per OEM's design split type casing is Agreed. not required. The same has been used for all our previous NTPC and Non NTPC Projects, including NTPC Lara, Kudgi and Tanda

2.13.1.1

Duct Work Sizing Criteria ii) The velocities in the ducts shall not exceed the above limits under the following conditions, all occurring together: 60 of 120 (b) 25% excess air over and above the stoichiometric air at economizer inlet.

As mentioned in tender fan to be sized considering 20% excess air, hence duct will also be sized considering 20% excess air. Further actual Air heater leakage will be considered for duct sizing.

Boiler design is based on 20% EA or more. All auxiliaries to be sized based on bidding Specification .

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Clause No.

2.13.1.2, iii)

2.13.1.2, iii)

Page no.

Bid Specification Stipulation

Loads for Duct and Structure Design Horizontal ducts to be designed for minimum 245 kg/m² additional fly ash loading on the surface or for one fourth of duct full of ash or for maximum possible accumulation of ash in the ductwork, under all normal, upset or abnormal operating conditions, whichever is 61 of 120 higher. For flue gas ducts downstream of ESP, additional fly ash loading on the surface or for one tenth of duct full of ash or for maximum possible accumulation of ash in the ductwork, under all normal, upset or abnormal operating conditions, whichever is higher.

72 of 120 Minimum headroom (free height) under all floors, walkways and stairs shall be 2.3m.

2.17.16. iii

27.5.3

Horizontal flue gas ducts shall be designed additionally for minimum 360 kg/m2 fly ash loading on the surface for flue gas ducting up to ESP inlet and minimum 60kg/m2 fly ash loading on surface for the flue gas ducting after ESP to chimney inlet, as per bidder's standard Practice. SJVN/DESEIN to confirm the same.

Owner's Reply

The provision as per bidding specification shall prevail.

Economizer By-pass duct shall be designed considering ash accumulation as Loads for Duct and Structure Design per bidder’s standard and proven practice. The ash accumulation considered for economizer bypass duct (if The provision as per SJVN/DESEIN to confirm the same. provided) upto Guillotine gate shall be 100% filled with ash. The 61 of 120 bidding specification shall ash density for the purpose of loading shall be at least 1350 kg/m3. prevail. iii) The soot blowers shall be capable of selective operation in areas of ash deposition (SMART) type or equivalent.

2.15.2

Statement of Prebid Queries & Clarification

As per Bidder standard conventional sequential based soot blowers shall be provided. This soot blowers shall be capable of selective operation in areas of ash deposition.

Agreed.

Bidder shall endeavour to ensure 2 meters clear head room above walkways since it will be very difficult for supporting purposes.

79 of 120 Over head piping shall have a normal minimum vertical clearance 8 of 35 of 2.5M above walkways.

14

Clear Head room within Main 2.5m (Minimum) Plant Building for 8 of 15 pipes, ducts, structures & cable trays etc.

25

Valves including actuators and instrument tappings shall be located in accessible positions and operating/maintenance 10 of 15 platform for the same shall be provided. All piping shall be routed at a clear height of 2500mm (min.) from the nearest access level to clear man movement

The provision as per bidding specification shall prevail.

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Clause No.

2.17.19.1

Page no.

84

85

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6.08.00

2.21.1

2.21.4, iv)

2.21.4, 1), iv)

Statement of Prebid Queries & Clarification

Handrails (for staircases, around openings, in walkways etc.) shall Bidder shall follow the handrail requirement for boiler as specified in the mechanical specification Volume-III /Cl 2.17.19.1 of Section 2 Chapter 1. be of standard weight steel pipe of flush welded constructions, Kindly confirm. ground smooth using 32 mm nominal bore medium class pipe provided with double rail, top rail about 1.0 metre above platform level and pipe posts spaced not more than 1.5 metres apart. Toe 81 of 120 guard of size 100mm x 6 mm shall be provided along the railing for all steelplatforms/landings and RCC staircases.

83

Ch 6: General Requirement of Building & Structure/ Vol-VI

Bid Specification Stipulation

3 of 9

All handrails shall be of 32mm nominal bore MS pipes (medium class) as per IS:1161 galvanised using 750 gm/sq. m of zinc. Handrails for platforms, walkways and projections shall be a tworail 450mm below the top rails. Handrail post spacing shall be limited to 1500mm as far as possible but can be proportioned to the length of the protected horizontal opening. Handrails shall be shop fabricated for specific locations and field welded or bolted to the erected structural steel. For platforms at elevation more than 30m, three rail system with top rail at 1500mm shall be adopted.

Full range and full scale performance testing shall be conducted at shop on one number each of the following Fans as per BS 848, Part-1: i) Induced Draft Fan 82 of 120 ii) Forced Draft Fan iii) Primary Air Fan iv) Seal Air Fan v) GR Fan (if applicable) a) SCR reactor design and its supporting system shall be suitable for accommodating all catalyst types (i.e. plate, honeycomb, 88 of 120 corrugated) for both current and future catalyst installation. SCR Reactor Configuration b) The vertical clearance distance between top edge of catalyst 88 of 120 module and bottom edge of the bearing support structure for the next layer above it or the layer of flow modification device shall be at least 2000 mm.

Conductance of full range performance testing at shop is practically not feasible with most of the vendors. We will provide proven fan models with end user certificates, as available

SJVN/DESEIN to note that the SCR reactor and its supporting system shall be designed with the provided catalyst type considering future provision and not with any type of Catalyst.

Owner's Reply

Agreed. The provision as per bidding specification shall prevail. For Boiler and other BOP package Steel Structure clause 6.08 Chapter 6 is applicable for all buildings/STG buildings under Civil Works.

Performance & routine test to be done at Shop. Full load per test at site to be followed as per bidding specification.

Agreed.

The vertical clearance distance between top edge of catalyst module and bottom edge of the bearing support structure for the next layer above it or the The provision as per bidding specification shall layer of flow modification device shall be as per OEM standard. prevail. SJVN/DESEIN to confirm the same.

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88

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89

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90

91

92

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Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

2.21.4, 2), i)

2.21.4, 2), i)

2.21.4, 2), iii)

2.21.4, 2), iii)

2.21.4, 2), vi)

2.21.4, 3)

2.21.4, 3, iii)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Reactor Housing Design a) The SCR reactor shall be weatherproof and water tight 88 of 120 construction for protection from monsoon rains/winds and have drainage arrangement like gutters, drain pipes etc., as applicable, connected to plant drainage system at ground level. Reactor Housing Design d) The reactor load shall be transferred from the reactor side walls, equally distributed via springs and external slide bearing pads, to 89 of 120 the supporting steel structure.

Bidder will provide suitable insulation and cladding for SCR similar to RAPH The provision as per for weather protection of SCR system. However, separate drainage arrangement like gutters, drain pipes etc. are not required as the SCR is kept bidding specification shall prevail. in open area.

Reactor Housing Design a) Capable of taking additional loads due to accumulations of ash 89 of 120 upto 150mm height above catalysts for each layer including future layer.

Such operating condition may not be experienced in the entire life of plant and hence shall not be considered by bidder for any design. However as per OEM standard the expected ash load in SCR shall be considered for design.

Based on bidder experience and proven practice the requirement of reactor load transfer via springs and external slide bearing pads, to the supporting steel structure is not envisaged. Bidder shall be allowed to transfer load via flat bearing pads only, to the supporting steel structure. SJVN/DESEIN to confirm the same.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

According to bidder's standard practice, 10% of catalyst weight is considered Reactor Housing Design as ash choking load in catalyst. The SCR reactor and its supporting system shall be designed for the following: b) Catalyst modules including the future layer 50% filled with ash The provision as per and ash hopper (if applicable) filled up to the top of the hopper 89 of 120 partition plane. bidding specification shall prevail. This additional load shall be considered over and above other loads considered for reactor casing and frame design. The ash density for the purpose of ash loading shall be at least 1350 kg/m³. Each catalyst elevation shall be provided with grated platform inside the reactor housing to support and place the catalyst 90 of 120 modules.

Based on bidder experience and proven practice the requirement of grated platform inside the reactor housing to support and place the catalyst modules The provision as per bidding specification shall is not envisaged. prevail. SJVN/DESEIN to confirm the same.

Catalyst modules ii) The upper edge of the catalyst shall be hardened to minimize 90 of 120 ash erosion.

Hardening of upper edge is applicable for honeycomb type catalyst only and hence this is not applicable /feasible for plate type catalyst.

Depth of the module shall be as per OEM standard. Catalyst modules Depth of the module shall be determined based on cleaning 90 of 120 efficiency of the selected catalyst dedusting system but shall not be higher than 1300 mm.

Agreed.

The provision as per bidding specification shall prevail.

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95

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Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

96

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Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

2.21.4, 3)

2.21.4, 4)

2.21.4, 4)

2.21.6

2.21.7, 9)

Page no.

90 of 120

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

There is no such analyser or technology available in market to measure Catalyst modules xv) In situ measurement of catalyst activity shall also be envisaged. catalyst activity in-situ. Hence this is not envisaged.

SJVN/DESEIN to note that Dry cleaning if required shall be performed offline Catalyst De-dusting System Cleaning effectiveness shall target recovery, as measured through instead of in-situ cleaning. gas pressure drop and visual inspection, up to a near pressure drop value with reference to completely clean reactor as measured at the time of commissioning. In case if above dedusting systems 92 of 120 are not sufficient for effective cleaning of the catalyst than the bidder may provide Dry Cleaning System for in-situ cleaning of the catalyst in addition to above.

Owner's Reply The bidder shall have the facility to perform the sample lab. test twice/year at site.

Agreed.

iv) Dry Cleaning System for in-situ cleaning shall include removal of the particulates and plug(s) on the catalyst using a blasting 94 of 120 stream of a pressurized carrier gas having a particulate blasting medium (dry ice) directed at the SCR catalyst. CFD and Physical Flow Modeling 2) The model shall predict dependencies of NH3/NO ratio, temperature, residence time and flue gas composition. The contractor shall provide the result of computer simulation for fluid 98 of 120 dynamics of the SCR De-NOx system at 100% BMCR, 80% BMCR, 60% BMCR and turn down load for the SCR system. Contractor shall load the final CFD model alongwith all necessary files on Employer’s Computer.

100 of 120

Ammonia Injection System Components of ammonia injection system exposed to flue gas stream shall be constructed from suitable grade of stainless steel. The common supply header and riser pipes outside the flue gas stream shall be of carbon steel (ASTM A106, Grade B) material. AIG system piping shall be provided with proper supports for the injection grid taking into consideration off thermal stresses and vibration caused by the flue gas flow.

Flue gas composition will not be simulated by both CFD and model test. However the velocity distribution, ash distribution, temperature distribution study shall be conducted with CFD simulation.

SJVN / DESEIN to note that the ammonia injection grid (AIG) nozzle orifice shall be made of stainless steel material whereas the interconnecting piping for ammonia injection system shall be selected based on the flue gas temperature inside the duct.

CFD & Model tests to be done as per standard practice as required for SCR.

The provision as per bidding specification shall prevail.

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99

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Section / Part / Chapter / Volume Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

Clause No.

Page no.

2.21.23

115 of 120

2.10.1, iii), c)

33 of 120

Civil & Structural Works/Ch 07: Material/Vol-VI

7.1

1 of 1

Ch 27 : Low Pressure Piping, Valves & Specialities/ Vol-III

27.3.5, 5)

6 of 35

Section 2 : Design Basis of SG & Auxiliaries and SCR/Ch 1: SG & Auxiliaries/Vol-III

101

Ch 26 : Power Cycle Piping, Valves, Fittings & Thermal Insulation/Vol-III

26.14.1.1, 5)

18 of 26, 19 of 26

102

Ch 26 : Power Cycle Piping, Valves, Fittings & Thermal Insulation/Vol-III

26.14.3, d)

23 of 26

104

Ch 03: Instruction to Bidder/ Vol-VI

As mentioned in tender fan to be sized considering 20% excess air, hence reactor shall also be sized considering 20% excess air. SJVN/DESEIN to confirm.

Minimum thickness of stainless steel liner on the inner surface of hopper wall shall be 4 mm confirming to grade SS 304.

Bidder shall provide the SS lining (SS304/4mm thick) in line with Cl. No. 2.10.1, iii), c), for conical portion of coal bunker provided at boiler area. SJVN/DESEIN to confirm.

Complete hopper including vertical and conical portion of bunker in mill building shall be provided with lining of atleast 4 mm thick SS plate grade SS 316L . Discrepancy is observed in the Fuel oil piping code. Bidder shall follow the fuel oil piping code as per clause no. 2.11.3, xiii), i) SJVN/DESEIN to confirm the same.

a) Fuel Oil Piping - IS1978 or ASTM-A-106 Gr. B or approved equivalent 53 of 120

Ch 33: Plant Layout Requirement/Vol-III

Statement of Prebid Queries & Clarification

A) SCR System Sizing shall comply the following: 2) Each Reactor shall be sized - 25% excess air

Fuel Oil piping : API 5L

2.11.3, xiii), i)

103

Bid Specification Stipulation

28

3.2.3

The provision as per bidding specification shall prevail.

Agreed.Bidder to follow as per clause 2.10.1(iii) c for the inner surface of hpper complete.

Agreed. Bidder to consider 2.11.3 xiii)i

Thermal conductivity of insulation material : Not less than maximum values as per IS: 8183.

Thermal conductivity value - Not more than maximum values as per IS:8183. Please confirm. The provision as per bidding specification shall prevail.

Screws Stainless steel Self-tapping, cheese headed.

As per bidders Standard practice, Screws shall be of galvanized steel, check headed self tapping type. Above 400°C temperature, screws shall be stainless steel.

FD, ID and PA fans handling arrangement complete with crane Complete with crane and handling facilities is not possible for FD, ID and PA and handling facilities along with removal space shall be provided. fans handling. As per Bidder standard, electric hoist will be provided for A continuous platform shall be provided between fan and motor handling. 10 of 15 end for ID/PA/FD fans in order to facilitate movement of personnel.

3 of 5

Owner's Reply

Proof checking of structural design of following structures shall be Mill Building and Bunkers are forming an integral part of Boiler Structure. got from IIT Roorkee/Reputed Govt. Institution by the Contractor at Since Boiler Structure is Proprietary in nature, Proof checking of the same his own cost. shall be waived off. (c) Design and connection of Mill Bunker building main structural frame work including design of Bunkers.

The provision as per bidding specification shall prevail.

Agreed.

The provision as per bidding specification shall prevail.

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105

106

107

108

Section / Part / Chapter / Volume

Clause No.

Ch 04: Submission/ Vol-VI

Ch 11:Building Description/ Vol-VI

4

11.3

Page no.

1 of 3

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Mill Building is an integral part of Boiler Structure. Since Boiler Structure is The analysis of TG building, Mill building, ESP control room, Chlorination building, Switchyard control building, CW pump Proprietary in nature, submission of Analysis documents pertaining to Mill house, Raw water pump house, Ash water pump houses and Building shall be waived off. Service building are to be done by developing 3D mathematical model adopting response spectra method of analysis as per IS: 1893-2002 & 2005, in addition to wind load analysis as per IS: 875 Part-3

Two nos. of staircase shall provide access to all floor/platforms extending upto the roof level. Requisite nos. of corridor as per operational requirements shall be provided to access steam 6 of 16 generator building from Mill building. The Mill building and steam generator building shall have expansion gap and corridor shall be connected with sliding supports.

Both Boiler Structure and Mill Building are Cold Structures. So there is no Expansion Gap between Mill Building and Boiler Building. All of Bidder's experiences are integrated type and bidder would like to apply the integrated steel structure to Mill and Bunker bay building. This type of structure will guarantee a structural stability.

2x100% seal air fas arrangement is required for all the isolation Since, there will be negative pressure from ECO to IDF inlet, "2x100% Seal damper which are located from Eco oulet to RAPH (Flue gas side). air fan arrangement" is not required for the dampers which are located at However seal air fan arrangement is not required for ESP inlet and upstream of RAPH, as like in ESP inlet, ESP outlet and ID fan inlet. outlet, ID fan inlet isolation dampers. Volume VII-Tender Dwg no. 111-1115 of 63 Hence, Bidder shall not consider the requirement of "2x100% Seal air fan Drawings -Mechanical 1200 arrangement" for all isolation dampers at Eco/SH bypass duct and RAPH inlet (Gas side). Volume VII-Tender Drawings -Mechanical

62 & 63

In drawing Dwg.no: D-0444-111-23-5209_Rev 0, extension of mill bay shown in between bunker & junction tower.

SJVN/DESEIN to confirm As per OEM standard, extension of mill bay shown in between bunker & junction tower is not applicable.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Agreed.

B

STEAM TURBINE (MECH)

1

Ch.2 : Steam Turbine and its Auxiliaries Section-1: Scope of Works

1.2.2.2 Steam Turbine Auxiliary Systems

2

Ch.2 : Steam Turbine and its Auxiliaries Section-1: Scope of Works

1.13 OTHER Sheet 9 vi) Chemical cleaning of all equipment and systems after their Chemical cleaning for turbine and its components is done at shop before MISCELLANEO of 12 erection shall be in Bidder's scope. sending to site for assembly, hence any chemical cleaning is not envisaged Agreed, however during US ITEMS after erection. commissioning oil flushing by the bidder.

3

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

2.16 TURBINE LUBRICATION OIL SYSTEM

Sheet 5 x) Boroscopic inspection ports in turbine for in situ inspection of One number of boroscope for complete station shall be provided. of 12 turbine internals shall be provided as per bidder standard practice. One no turbine for complete station shall be provided.

Sheet 15 In case of complete power failure including DC supply, Turbine Overhead tank for safe coasting down is not envisaged as per Bidders of 70 Generator set shall be capable of safe coasting down. Bidder shall Proven practice considering the increased reliability of electrical systems. consider overhead lube oil tank for safe coasting down of turbine.

Agreed. One No. Boroscopic for complete station shall be provided.

The provision as per Bidding document shall prevail.

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Section / Part / Chapter / Volume Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

Clause No. 2.16 TURBINE LUBRICATION OIL SYSTEM

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Sheet 15 Each unit Lube Oil tank of SS to have capacity to allow 5 to 8 oil Material of Lube oil tank is carbon steel meeting the system requirement and of 70 charges per hour (at normal operating level), fitted with is as per proven practice of the Bidder. noncorrodable strainers, level transmitter & local indicators and necessary manholes, 2x100% duty vapour extraction fans, platforms, railings, necessary piping, supports, ladder and accessories etc. The provision as per Bidding document shall prevail.

5

6

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

2.16.4 Oil Sheet 17 All the piping, fittings, valves, Main Oil Tank and complete strainer Piping & fittings of 70 including body & element shall be of stainless steel. Further all the parts of lube oil coolers (tubular or plate type) which are coming in contact with lube oil shall be of stainless steel

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

2.16.4 Central Turbine Lubricating Oil Storage & Purification System

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

2.20.1 Other Sheet 25 Final feed water temperature optimized at of 70 100% TMCR 306°C conditions for computing heat balance diagrams:

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

2.2.2.1

5.1 FEED WATER HEATING

Sheet 18 iii) 2x100% capacity oil transfer pumps with provision to add new 1X100% transfer pump is required for bidders system and is as per bidders of 70 oil to any unit oil tank. proven practice. The same shall be supplied.

Sheet 3 l) Final feed water temp. for Heat Rate of 70 guarantee point & EMCR condition By Bidder but not less than 300°C at the terminal point.

The provision as per Bidding document shall prevail.

Bidder understands that Final feed water temp. for Heat Rate guarantee point & EMCR condition shall be optimized by Bidder but not less than 300°C at the terminal point. Please confirm.

Confirmed.

Sheet 41 The plant shall be suitable for operation in conjunction with the of 70 turbine. It shall be designed for raising the temperature of feed water from that in the condenser to a final feed water temperature of 306ºC at the outlet of top heater at rated output with zero percent make-up and design back pressure.

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Section / Part / Chapter / Volume

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Sheet 64 8.4.1.3 The steam turbine generator unit alongwith auxiliaries is Bidder understands that Sliding Pressure Operation from rated pressure of 70 normally expected to operate in sliding pressure mode from rated down to 40% of rated pressure with as well as without any throttle reserve pressure down to 40% of rated pressure in conjunction with steam shall be considered. generator, HP-LP bypass system and plant instrumentation and control system.

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

8.4 Availability Requirements of TG and Auxiliaries

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

Sheet 21 2.19.3 Ensure during sliding pressure mode, throttle pressure 2.19 PERFORMANC of 70 slides from rated pressure corresponding to 40% of BMCR load. E REQUIREMENT S 2.20.1 Other Sheet 26 vii) In the sliding pressure mode of operation the throttle pressure conditions for of 70 will slide down from rated pressure to a value corresponding to computing heat 40% of rated pressure balance diagrams:

Ch2: Steam Turbine and its Auxiliaries Section-2: Design Basis

8

Clause No.

Ch 3 : Operating Capability of Plant

1.0 OPERATING CAPABILITY OF PLANT

EPC PACKAGE VOLUME-I, SECTION – III

BID DATA Page 53 Turbine Cycle Heat Rate in kcal/kwhr under rated steam conditions Owner is requested to check/revisit evaluation rate with respect to Liquidated SHEETS (BDS) of 63 at guaranteed optimized condenser pressure with zero make-up at Damages for 100% TMCR Heat rate case. 660 MW Unit Load (i.e. 100 % of rated load) Rate of Bid evaluation (BEF) INR 119 Million (Rupees One Hundred Nineteen Million Two hundred Thousand only) or equivalent foreign currency for 1 kCal /kWh increase in heat rate over lowest quoted Heat Rate as base. RATE OF LIQUIDATION DAMAGE (LD) INR 58,200,000/-(INR Fifty Eight Million Two Hundred Thousand only) or equivalent foreign currency for per 1Kcal/Kwhr increase in heat rate

The modified sliding pressure operation envisaged at Boiler end is from 100% BMCR to 40% BMCR.

Sheet 2 (b) Sliding Pressure Operation from rated pressure down to 40% of of 3 rated pressure with as well as without any throttle reserve.

Refer Amendment -03

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10

Section / Part / Chapter / Volume Ch 8 : Functional Guarantee & Liquidated Damages

Ch 8 : Functional Guarantee & Liquidated Damages

Clause No. 6.4

6.6

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Sheet 49 6.4 The performance guarantee test will be carried out after Owner is requested to please note that steam turbine being a dynamic of 78 successful completion of initial operation. Ageing allowance machine starts deteriorating from its first steam admission itself, hence bidder (beyond three months from the date of completion of initial request owner to allow ageing correction atleast from first synchronization. operation) will be given during evaluation of PG test results and hence guaranteed heat rates shall be increased by the amount calculated as per the formula given in Cl. No. 3.07, Sub-Section-3 of ASMEPTC-6 Report 1985 (Reaffirmed 1991). Period of ageing shall be considered from the date of successful completion of initial operation to the date of conductance of PG test.

Sheet 49 6.6 During Performance/ Acceptance test, following tests shall be Bidder request owner to revisit and clarify the difference between the two of 78 carried out for T.G. set with test grade instruments as per ASME tests in order to understand the expectation.Bidder understanding is the tests code. are same in either case under the given boundary conditions. (i) Guarantee Turbine Cycle Heat rate test at 693MW (105% rated load) corresponding to the heat balance diagram specified in the tender specification. (iii) Guarantee Output test of 693 MW (105% rated load) corresponding to the heat balance diagram specified in the tender specification.

Owner's Reply

The provision as per Bidding document shall prevail.

The provision as per Bidding document shall prevail. There are two guarantees: i) Turbine heat rate. Ii) Turbine output

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Section / Part / Chapter / Volume

Clause No.

C

BTG AUXILIARIES & PG (MECH)

1

VOLUME-I, SECTION – III

10.1

2

Volume-II, Chapter-4

3.1 (m)

Page no.

Bid Specification Stipulation

53 of 63 ADJUSTMENT FACTORS FOR BID EVALUATION : a) Turbine Cycle Heat Rate @ 105%TMCR b) Efficiency of the steam generator at 105% TMCR c) Turbine Cycle Heat Rate @ 100%TMCR d) Efficiency of the steam generator at 100% TMCR e) Coal Pulverize wear parts warranty Life f) Unit Auxiliary Power Consumption for Unit Auxiliaries g) Station Auxiliary Power Consumption h) ammonia consumption rate i) limestone consumption of FGD system

Statement of Prebid Queries & Clarification

Owner's Reply

It is observed that Bidders quote very aggressive performance guarantee values during bidding stage in order to get the benefit during bid evaluation. However, these values quoted may be difficult to achieve during contract execution stage which is a loss to owner for long term. Hence we would like to bring for your kind notice that in recent tenders of NTPC, THDC etc. they have fixed the minimum technical guarantees considering plant load factors , The provision as per cost benefit analysis and usefulness of such evaluation in practcialilty over bidding document shall life span of plant. Request you to relook such high evaluatuion of technical prevail. paramaters in above context.

2 of 40 Provenness :

Bidder requests owner to modify the provenness criteria for HP heaters as per below. The same is followed by NTPC & other stae electricity boards in Feed Water High Pressure Heaters : Horizontal, U-tube type, their latest tenders. having integral de-super heating, condensing and drain cooling zones for steam turbine generator sets. Feed Water High Pressure Heaters : Horizontal, U-tube type, having integral Equipment rating : Capacity not less than 800 Ton/hour for de-super heating, condensing and drain cooling zones for steam turbine The provision as per bidding document shall generator sets each string Equipment rating : Feed Water High Pressure Heater of a 500 MW or prevail. higher size unit

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Section / Part / Chapter / Volume Volume-II, Chapter-5

Clause No. 26.2 (b)

Page no.

Bid Specification Stipulation

35 of 91 b) The 'Initial Operation' of the complete facility as an integral unit shall be conducted for 720 continuous hours. During the period of initial operation of 720 hours, the unit shall operate continuously at full rated load for a period not less than 72 hours. The Initial Operation Test shall be considered successful, if during the above period of initial operation, the 660MW unit shall generates a minimum of 451 million kWhrs*, as measured a generator terminals.

4

Volume-II, Chapter-5

28.6

Statement of Prebid Queries & Clarification

Owner's Reply

We request owner to modify the clause as below inline with NTPC & other stae electricity boards tender specifications as generation of 451 million kWhrs equates to 95% of continuous maximum power generation at TMCR for 30 days, which is very stringent during first month of plant operation: b) The 'Initial Operation' of the complete facility as an integral unit shall be The provision as per conducted for 720 continuous hours. During the period of initial operation of bidding document shall 720 hours, the unit shall operate continuously at full rated load for a period prevail. not less than 72 hours.

The Initial Operation Test shall be considered successful, if during the above period of initial operation, the 660MW unit shall generates a minimum of 451 illi kWh * d t price t i l submission. Please confirm 38 of 91 Exact details, extent of training and the training schedule shall be Training schedule to be finalized before bid finalised based on the Bidder's proposal within two (2) months from acceptance. placement of award.

Agreed.

5

Volume-II, Chapter-5

28.10

38 of 91 In addition to above, the contractor shall also arrange for training Training at other operating plants is not possible as other owners will not give of 30 Owner’s Personnel at a running 660 MW unit on operation of permission for the same. Hence only class room training as defined in power station, for a period of six (6) months. ANNEXURE-VII of Volume II, Chapter 5 will be provided. Please confirm acceptance.

The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

For 100% TMCR guaranteed operating condition, Adjustment factor for bid evaluation rates provided for Turbine Cycle Heat Rate is higher than the Liquidated damage values provided. Owner is requested to relook into this & At 100% TMCR (660MW) Turbine heat rate : INR 58,200,000/- provide the revised Bid evaluation rates for 100%TMCR Turbine cycle heat (INR Fifty Eight Million Two Hundred Thousand only) or equivalent rate operating condition. foreign currency for per 1 Kcal/Kwhr increase in heat rate

Volume-II, Chapter-8

3.2 i)(b)

8 of 78 AMOUNT OF LIQUIDATED DAMAGES (LD) APPLICABLE UNDER CATEGORY-I GUARANTEES

VOLUME-I, SECTION – III

10.1 (c)

53 of 63 ADJUSTMENT FACTORS FOR BID EVALUATION

Refer Amendment - 03.

Turbine Cycle Heat Rate in kcal/kwhr under rated steam conditions at guaranteed optimized condenser pressure with zero make-up at 660 MW Unit Load (i.e. 100 % of rated load) : INR 119 Million (Rupees One Hundred Nineteen Million Two hundred Thousand only) or equivalent foreign currency for 1 k Cal / kWh increase in heat rate over lowest quoted Heat Rate as base

7

Volume-II, Chapter-8

3.2 ii)(a)

For 105% TMCR guaranteed operating condition, Adjustment factor for bid evaluation rates provided for Steam Generator Efficiency is higher than the Liquidated damage values provided. Owner is requested to relook into this & At 105% TMCR (693MW) Steam Generator Efficiency : INR provide the revised Bid evaluation rates for 105%TMCR Steam Generator 31,100,000/- (INR Thirty one Million one Hundred Thousand only) Efficiency. or equivalent foreign currency for per 0.1% decrease in Steam Generator efficiency.

8 of 78 AMOUNT OF LIQUIDATED DAMAGES (LD) APPLICABLE UNDER CATEGORY-I GUARANTEES

Refer Amendment - 03

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Section / Part / Chapter / Volume VOLUME-I, SECTION – III

Clause No. 10.1 (b)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

53 of 63 ADJUSTMENT FACTORS FOR BID EVALUATION :

Owner's Reply Refer Amendment - 03.

Efficiency of the steam generator at 105% TMCR (693 MW unit load) with zero make up while firing the design coal at rated steam parameters, rated coal fineness and rated excess air at economizer outlet. : INR 39 Million (Rupees Thirty Nine Million only) or equivalent foreign currency for per 0.1 % decrease in Steam Generator efficiency below highest quoted Steam Generator efficiency as base.

8

9

Volume-II, Chapter-8

Volume-II, Chapter-8

3.2

2.1 (2)

8 of 78 The Performance Guarantees which attract Liquidated Damages Turbine cycle heat rate at optimized vacuum is already guaranteed by bidder, (LD) are as follows: hence in order to avoid double loading separate guarantee & LD on i.) Turbine Cycle Heat Rate condenser pressure should be deleted. iv.) Condenser pressure in mm Hg (abs) Please confirm acceptance.

1 of 78 The guaranteed performance parameters furnished by the Bidder The performance test will be as per the test conditions, measurement in his offer, shall be without any tolerance values whatsoever and tolerances, uncertainties laid down by latest edition of ASME PTC / HEI etc. all margins required for instrument inaccuracies and other uncertainties shall be deemed to have been included in the Please confirm acceptance. guaranteed figures

The provision as per bidding document shall prevail.

The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume

Clause No.

10

Volume-II, Chapter-8

6.3

11

Volume-II, Chapter-8

3.10.1

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

49 of 78 Corrections to the test results for steam turbine shall be applied as During Performance Test, Make up water will be isolated and the correction per the correction curves listed in detailed technical specification. for change in system water storage will be applied as unaccounted for When the system is properly isolated for a performance test, the leakage. unaccounted for leakages should not be more than 0.1% of the design throttle flow at that load. To achieve the above value of unaccounted for leakages, the Bidder shall prepare the unit during The provision as per pretest available shutdown. However, during the test, if it is found bidding document shall that the unaccounted for leakage is more than 0.1% of design prevail. throttle flow at that load, then heat rate will be increased by an amount equal to half the difference between actual unaccounted for leakage expressed as percentage of design throttle flow at that load and 0.1% (allowed by the code).

21 of 78 (xix) Motor Driven Boiler Feed Pump Bidder understands that for the Aux Power guarantee purpose it will be (For this purpose only 15% of the deemed power consumed by the considered that MDBFP & TDBFP will be sharing equal load at 100% TMCR. MDBFP at 100% TMCR unit load shall be considered). Please confirm acceptance. The provision as per bidding document shall prevail.

12

Volume-II, Chapter-8

3.10.1

21 of 78 (ix) Debris filter flushing pumps (if envisaged)

Bidder understands that Debris filter is not envisaged in tender for this project. Please confirm bidder's understanding. The provision as per bidding document shall prevail.

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14

Section / Part / Chapter / Volume Volume-II, Chapter-8

Volume-II, Chapter-8

Clause No. 3.10.1

3.10.2 b)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

21 of 78 (xxxviii) Power consumption of fans, water pumps, exhausters of Bidder understands that air washer units are used in TG building only, Air washer units for TG building and whole main plant area at its hence, aux power shall be guaranteed for TG building Air washer unit only rated duty point. and not for whole main plant area.

24 of 78 Station Auxiliary Power Consumption ;

Please confirm bidder's understanding.

Agreed. Aux. power shall be guaranteed for TG building Air washer unit only and not for whole main plant area.

Owner is requested to confirm the following for the computation of guaranteed auxiliary power consumption of Air conditioning system.

70% duty factor is considered for computation of guaranteed aux. Power Consumption for air Conditioning system. Following Buildings to be considered : 1) Control rooms/CCR/ESP/ CHP/AHP and other control room. 2) DCS room

The station auxiliaries that shall be running during the guarantee test for calculating Pau_Stn " shall include but not be limited to the (a) required duty factor to be considered (b) clearly defined buildings to be considered following: b) Air Conditioning System Power consumption at motor input terminals of working units (i.e. excluding stand-by) at its rated duty point of Chilling machines, Chilled water Pumps, Condenser water Pumps, Air/water cooled condensing machines, precision air conditioners, Air handling units (AHU) fans, cooling towers, for the Air conditioning system. 15

Volume-II, Chapter-8

3.10.2 c)

Owner's Reply

25 of 78 c) Water System Pumps (Working Pumps) i.) Raw Water Pumps at River ii.) Raw water supply pumps for PT plant and Ash handling system iii.) AC & Ventilation system make-up pumps iv.) DM water make up pump v.) Potable water pumps vi.) Service water pumps. vii.) Clarified water feed pumps for DM plant viii.) Degassed water pump ix.) Waste water transfer pumps x.) Jockey Pumps for firefighting system xi.) Feed pumps for DM plant ii ) T lli t it t

As per specifications, "Working pumps" to be considered in the Station aux power system. However certain pumps from the referred list (e.g. ETP pumps, waste water transfer pumps, DM plant feed pumps, raw water pumps for AHP, potable water pumps, service water pumps, degassed water pumps, jockey pumps, Only continuously working Travelling water screens, its pumps set etc.) will not be working continuously. pumps which is required to operating within a shift Please confirm whether all pumps given in the list are to be considered in the with 100% duty factor shall aux power consumption OR only continuously working pumps are to be be considered. considered. Also please confirm duty factor to be considered for each pump given in the li t

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Section / Part / Chapter / Volume Volume-II, Chapter-8

Clause No. 3.10.2 c)

Page no.

Bid Specification Stipulation

25 of 78 g) Fuel Oil system Unloading and forwarding pumps of fuel oil system

Statement of Prebid Queries & Clarification

Owner's Reply

Owner is requested to confirm duty factor for the unloading & forwarding pumps.

1.0 (please reffer Page no. 24 of 78 of volume II, chapter 8, Clause 3.10.2 )

17

Volume-II, Chapter-8

3.10.2 c)

24 of 78 Station Auxiliary Power Consumption

Since Hydrogen generation plant is not mentioned explicitly in the drive list given in tender, its power consumption will not be considered while providing the Guaranteed Station Auxiliary Power Consumption. Please confirm acceptance. Confirmed.

18

Volume-II, Chapter-11

4

47 of 94 Dry running withstand capability shall be demonstrated and established on one Boiler Feed Pump and its corresponding booster pump. Feed pump shall be capable of accepting complete loss of water and must be capable of being shut down in a controlled manner and brought down to rest after being tripped from design condition with simultaneous closure of suction valve. To demonstrate the capability during shop testing, suction valve actuation should be fast in order to ensure operation during vapour phase. Pump shall then be restarted and bring it back to design condition

Dry run test for BFP is not envisaged. However, the offered BFP will be capable of safe coasting down to rest, upon any inadvertent closure of suction valve. Adequate protections & interlocks will be built into the system to prevent dry running of the pump for extended length of time. Boiler feed pumps are not tested for dry run for supercritical power plants, as per OEM recommendations. Type test certificate is also acceptable. Please confirm acceptance.

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Section / Part / Chapter / Volume Volume-II, Chapter-11

Clause No. 6

Page no.

Bid Specification Stipulation

48 of 94 String Test:- Operational Test of One Motor Driven Boiler Feed Pump assembly using contract Booster Pump, Drive Motor, Hydraulic Coupling and Main Boiler Feed Pump to include test as specified at 1 & 3 (a) & (b). Dry Run Test shall preferably be carried out during String Test.

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder requests to delete the String test requirements as per OEM recommendations. Further, all OEMs have confirmed that they do not have the test bed facility to conduct the string test. Please confirm acceptance. Confirmed.

20

Volume-III, Chapter-1, Section 2

3&4

3 of 120 Rating of Steam Generator(s) : Steam temperature at superheater outlet : 603°C Steam temperature at reheater outlet : 603°C

There is contradiction in these clauses related to Main steam & reheat steam temperature at the Turbine & Steam generator inlet. Bidder understands that following steam temperatures to be considered for Steam turbine & steam generator design & performance guarantee. Steam Generator(s) : Steam temperature at superheater outlet : 603°C Steam temperature at reheater outlet : 603°C STEAM TURBINE : Turbine throttle main steam temp. : 600 °C Reheat steam temp. at turbine inlet : 600 °C

Volume-III, Chapter-2, Section 1

1.1.1

2 of 12 ii. Main Steam temperature at HP Turbine inlet : 600±5°C. iii. Reheat steam temp at IP Turbine inlet : 600±5°C

Note: - * Maximum Operating Main Steam & Hot reheat temperature at Turbine inlet shall be 605°C. Note: - * * Maximum Operating Main Steam & Hot reheat ±5 DegC is operating margin. Turbine shall be designed for 605 DegC Agreed. Note mention temperature at Turbine inlet shall be 605°C. ±5 DegC is operating temperature. mentioned in clause 1.1.1, margin. Turbine shall be designed for 605 DegC temperature. Volume III, chapter 2, Please confirm acceptance. section 1, clause 1.1.1 is deleted.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 2.2.2.1

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

2 of 70 STEAM TURBINE : Turbine throttle main steam temp. : 600 °C * Reheat steam temp. at turbine inlet : 600 °C * Note: - * Maximum Operating Main Steam & Hot reheat temperature at Turbine inlet shall be 605°C. ±5 DegC is operating margin. Turbine shall be designed for 605 DegC temperature.

VOLUME-I, SECTION – III

10.1 (c)

53 of 63 ADJUSTMENT FACTORS FOR BID EVALUATION *Turbine Cycle Heat Rate in kcal/kwhr under rated steam conditions at guaranteed optimized condenser pressure with zero make-up at 660 MW Unit Load (i.e. 100 % of rated load) *Turbine Cycle Heat Rate in kcal/kwhr under rated steam conditions at guaranteed optimized condenser pressure with zero make-up at 693 MW Unit Load (i.e. 105 % of rated load)

Volume-II, Chapter-8

21

3.1 (i)

4 of 78 The Performance Guarantees which attract Liquidated Damages (LD) are as follows: i.) Turbine Cycle Heat Rate a) Turbine Cycle heat rate in kcal/kWhr under rated steam conditions at guaranteed condenser pressure with zero make up at 693 MW unit load (i.e. 105% of rated load). b) Turbine Cycle heat rate in kcal/kWhr under rated steam conditions at guaranteed condenser pressure with zero make up at 660 MW unit load (i.e. 100% of rated load).

Bidder understands that for Turbine cycle heat rate guarantee in the refered conditions rated steam conditions means the following. Turbine throttle steam pressure : 270 Kg/cm2 (abs) Turbine throttle main steam temp. : 600 °C Reheat steam temp. at turbine inlet : 600 °C Please confirm acceptance.

Confirmed.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 2.2.2.1

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

2 of 70 STEAM TURBINE : c) Turbine throttle main steam temp. : 600 °C * d) Reheat steam temp. at turbine inlet : 600 °C * Note: - * Maximum Operating Main Steam & Hot reheat temperature at Turbine inlet shall be 605°C. ±5 DegC is operating margin. Turbine shall be designed for 605 DegC temperature.

22

Volume-III, Chapter-1, Section 2

2.1.3.1

3 of 120 Feed water temperature at economiser inlet : By bidder

There is contradiction in these clauses related to Final feedwater temperature selection at 100%TMCR operating condition. Being an EPC tender bidder understands that final feedwater temperature to be as optimized by the biider but not be less than 300 Deg.c. Please confirm acceptance.

Volume-III, Chapter-2, Section 2

2.2.2.1

3 of 70 Final feed water temperature optimized at 100% TMCR : 306 °C

Agreed. Final feedwater temperature to be as optimized by the biider but not be less than 300 Deg.c.

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23

Section / Part / Chapter / Volume

Clause No.

Volume-III, Chapter-2, Section 2

2.20.1

Volume-III, Chapter-2, Section 2

2.9.2 (i)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

25 of 70 l) Final feed water temp. for Heat Rate guarantee point & EMCR condition : By Bidder but not less than 300°C at the terminal point.

11 of 70 During normal operation, turbine shall be self-sealing. However BFP Drive turbine glands may be self sealing or externally sealed as per BFP drive Turbine shall be preferably be of self sealing type. OEM standard practice. Please confirm acceptance. Confirmed.

24

Volume-III, Chapter-2, Section 2

2.2

23 of 70 (k) VWO output under rated steam conditions at worst condenser Bidder understands that VWO output in the refered clauses means output corresponding to VWO flow. pressure with 1% make-up. (l) VWO output under rated steam conditions at design condenser pressure with 1% makeup. Please confirm acceptance. Confirmed.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 2.2

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

23 of 70 (n) All HP heaters out of service under rated steam conditions at During all HP heater out condition output will be limited corresponding to design & worst condenser pressure with zero percent make up and 100% TMCR heat duty. 1% make-up and rated output Please confirm acceptance. The provision as per bidding document shall prevail.

26

27

Volume-III, Chapter-2, Section 2

Volume-III, Chapter-1, Section 2

2.2

1

24 of 70 (u) Steam Generator output corresponding to BMCR flow under rated steam condition, turbine under VWO operation, worst condenser pressure 1% make up at rated feed water temperature. Difference of BMCR flow and VWO steam flow through turbine shall be assumed to be drawn off from Main steam line. Same quantity of flow to be added to condenser as additional make up. (GURANTEED STEAM GENERATOR CAPACITY)

3 of 120 BMCR PARAMETERS : Steam flow at superheater outlet : 102% of the turbine VWO steam flow requirement plus continuous aux steam requirement of unit at TMCR rounded to next integer divisible by 5.

Bidder will consider the BMCR parameter for steam generator as follows. Steam flow at superheater outlet : 102% of the turbine VWO steam flow requirement, design condenser pressure, 0% make up, optimized feedwater temperature rounded to next integer divisible by 5. Please confirm acceptance.

The provision as per bidding document shall prevail.

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29

Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Volume-III, Chapter-2, Section 2

Clause No. vii)

3.2

Page no.

Bid Specification Stipulation

26 of 70 In the sliding pressure mode of operation the throttle pressure will slide down from rated pressure to a value corresponding to 40% of rated pressure. For computing heat balance for sliding pressure mode of operation at 80%, 70%,60%, 50% and 40% of Unit rated load, rated temperature of 600°C and 600 deg.C shall be used for main steam and hot reheat steam respectively.

Statement of Prebid Queries & Clarification

Owner's Reply

It is not possible to maintain the Rated temperature (600 Deg.c) for Main Confirmed. steam and hot reheat steam for sliding pressure mode of operation below 50% of Unit rated load. Main steam and hot reheat steam temperature below 50% of unit load shall be as per Bidder design. Please confirm acceptance.

28 of 70 Condensing Plant : Condenser shell, Hotwell, condenser neck material will be carbon steel as Shell material carbon steel as per ASTMA-285 Gr.C or equivalent per ASTMA-285 Gr.C / SA 516 Gr.70 / IS 2062 or equivalent. & suitable for intended service, welded construction and 16mm minimum wall thickness. Please confirm acceptance. The provision as per bidding document shall prevail.

30

Volume-III, Chapter-2, Section 2

3.3.1 (i)

There is contradiction in these clauses related to design cooling water flow requirements. Bidder understands that 82000 m3/hr as indicated in the VolDesign circulating water quantity at inlet temperature of 33 degC : III, Chapter-2, Clause 3.3.1 is the fixed circulating water quantity available for condenser design. Cooling water flow of 76000 m3/hr as shown in composite 82000 M3/hr. water scheme is indicative only.

30 of 70 Design Parameters For Condenser and Associated Systems :

Please confirm bidder understanding.

Bidder to follow Design flow to Condenser - 76000 3

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Section / Part / Chapter / Volume Volume VII-TDMechanical

31

Volume-III, Chapter-2, Section 2

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

M3/hr with margin of flow 82000 M3/hr.

Dwg.no. 111-12- 19 of 63 Composte water scheme : 3100 Cooling water flow to condenser is shown as 76000 m3/hr

3.3.1 (e)

30 of 70 Tube velocity: 1.6 to 2.2 m/sec

Please note that considering 5% tube plugged, the maximum velocity will be 2.2 m/sec. However, when all 5% tubes are plugged and if margin on CW flow is considered (i.e. 5% more than the flow is considered as compared to HMBD), the maximum velocity will be more than 2.2 m/sec. Please confirm acceptance.

32

Volume-III, Chapter-2, Section 2

3.9 (viii)

Owner's Reply

The provision as per bidding document shall prevail.

37 of 70 (b) ……………. While sizing the condensate extraction pumps the Being an EPC tender pressure drop across CPU will be as optimized by the pressure drop of 3.5 Kg/cm2 for condensate polishing unit shall be bidder. taken into account in the discharge head of CEP. Please confirm acceptance. The provision as per bidding document shall prevail.

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34

Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Volume-III, Chapter-2, Section 2

Clause No. 3.9 (xi)

5.1 (ii)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Since the CEP will be installed below ground floor, to maintain necessary NPSHa the motor will be installed just above pump & not at ground floor Bottom of motor to be above zero meter by suitably considering elevation. Necessary access shall be provided for motor approach. the pit level and motor stool dimensions Please confirm acceptance.

38 of 70 Motor bottom level

41 of 70 TTDs and DCAs of heaters shall correspond to the VWO operating There is discrepancy found in the two clauses. Feedwater heaters will be conditions designed based on 100%TMCR operating condition & TTDs and DCAs of the feed water heaters shall be demonstrated as per guaranteed heat balance diagram for 100% TMCR condition. Please confirm acceptance.

Volume-II, Chapter-8

5.14

Owner's Reply

The provision as per bidding document shall prevail.

The provision as per bidding document shall prevail. Designed for VWO operating conditions but shall be demponstrated as per heat balance at 100% TMCR

29 of 78 a) TTDs and DCAs of feed water heaters shall be demonstrated as per guaranteed heat balance diagram for 100% TMCR condition.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 5.1 (ix)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

42 of 70 Tube material shall be stainless steel as per ASTM. A 213 Gr. TP Bidder alternately requests to allow option of using TP304N tubes for feed 304 for seamless tubes without circumferential joints or ASTMA water heaters. This has been accepted in supercritical projects including 688 Gr. TP 304 for welded tubes. Maximum content of carbon shall NTPC & other state electricty board projects. be limited to 0.05%. Please confirm acceptance. Confirmed.

36

Volume-III, Chapter-2, Section 2

5.1 (x)

42 of 70 Tube sheet material shall be carbon steel as per ASTM. A516 Alternately A266 Gr.2 tube sheet material should be also accepted for LP Grade 70 or SA 350 LF-2 and shall be welded to shell and water heaters. box. Tube support plates of common quality steel of 16mm (min) thickness Please confirm acceptance. The provision as per bidding document shall prevail.

37

Volume-III, Chapter-2, Section 2

5.4 (vi)

48 of 70 All water spray valves, splash plates, trays, vent condenser and For STORK type deaerator only the sprayer will be made from Stainless steel other elements in contact with undeaerated water or as per the OEM standard & proven practice. noncondensable gases shall be of stainless steel SS-304 or SS 410 Please confirm acceptance. The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 5.4 (xi)

Page no.

Bid Specification Stipulation

48 of 70 Deaerator pressure shall vary with load when it gets steam from turbine extraction. Design pressure & temp. shall not be less than extraction /CRH pressure or worst operating condition with sufficient margins above the same.

Statement of Prebid Queries & Clarification For stork type deaerator, design temperature will be: 5°C higher than saturation temperature corresponding to the design pressure or 205°C whichever is higher. The design temperature of the deaerator parts in contact with extraction steam shall be equal to extraction design temperature or worst operating condition. This is inline with HEI standards.

Please confirm acceptance.

Owner's Reply

The provision as per bidding document shall prevail.

39

Volume-III, Chapter-2, Section 2

7.3.1 (vii)

54 of 70 MD-BFP lube oil system Common lubricating oil system shall be provided for main BFP, booster pump, motor and hydraulic coupling with 2X100% AC motor driven auxiliary oil pumps (if there is no shaft driven in MDBFP) & 1X100% AC motor driven auxiliary oil pumps (if there is shaft driven in MDBFP), two full capacity each of working oil cooler/lube oil cooler/ oil filters/ strainers and piping, valves, fittings, instruments etc. as required.

As per proven and standard practice of Bidder and OEM, 1x100% AC motor driven auxiliary oil pump and 1x100% shaft driven oil pump is envisaged for MDBFP. Bidder further proposes to consider 1x100% lube oil cooler, 1x100% working oil cooler, as the MDBFP is a stand-by equipment. Also, Bidder would like to highlight that this is the standard configuration offered by the Confirmed. reputed OEM of hydraulic coupling i.e Voith. Bidder to consider 2x100% Please confirm acceptance. lube/working oil cooler.

40

Volume-III, Chapter-2, Section 2

7.7.8 (i)

62 of 70 Each drive turbine shall be provided with a complete lubricating oil system which shall provide lube oil for drive turbine, main pump, booster pump and disconnect coupling and also to cater the control oil of governing system and turning gear oil requirements.

Bidder proposes flexible coupling between BFP drive Turbine and BFP as per the standard proven practice of OEM. Flexible couplings are simplified in design and lot of accessories required for disconnect couplings (like hydraulic pumping unit, hydraulic actuators etc.) are not applicable. Dis-engagement is by simple dismantling of spacer bolts. Please confirm acceptance.

Confirmed.

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Section / Part / Chapter / Volume Volume-III, Chapter-2, Section 2

Clause No. 7.9

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

63 of 70 Location of TDBFPs & MDBFP Being an EPC tender location of TDBFP & MDBFP shall be as per standard TDBFPs to be preferably located on operating floor and MDBFP to practice of the bidder. be located on ground floor (0.0M) Please confirm acceptance. Confirmed.

42

42

Volume-III, Chapter-2, Section 2

Section-2 / Chapter-1 / Volume-III

7.7.2 (i)

2.16.1.1

59 of 70 Design of BFP Drive Turbine: Design of drive turbines shall be Bidder proposes to design BFP drive turbine as per IEC 45 / API 612 & 614 generally in accordance with API 612 and 614 except… Testing in and as per their standard proven practice. Please confirm acceptance. accordance with ASME PTC-6. Further Bidder would like to inform that a separate PG test as per PTC-6 is not envisaged exclusively for BFPDT as the same is part of overall PG test done for the STG. Owner is requested to confirm.

The provision as per bidding document shall prevail.

74 of 120 The operating parameters of the aux. steam header shall be of HT header operating temperature will be more than 250 deg C. However LT optimized by the bidder maintaining a minimum temperature of header temperature will be around 215 to 220 deg C based on end consumer 250°C and minimum superheat of 50°C. requirements. Please confirm acceptance. Confirmed.

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Section / Part / Chapter / Volume Section-2 / Chapter-1 / Volume-III

Clause No. 2.16.2

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

75 of 120 High Capacity PRDS shall be sized for auxiliary steam requirement High Capacity PRDS capacity at 60% load shall be finalized based on end of 150 TPH* (minimum) with main steam parameters consumer requirements. corresponding to 60% load. Please confirm acceptance. The provision as per bidding document shall prevail.

44

Section-2 / Chapter-1 / Volume-III

Section-2 / Chapter-2 / Volume-III

2.16.5

2.18.7

75 of 120 During cold startup the deaerator pressure shall be maintained at 1.5 ata with steam from auxiliary steam header. During hot and warm startup deaerator pressure shall be maintained at 3.5 ata. However, in case startup drain circulation pumps are not in service and startup drains are routed through condenser, deaerator pressure shall be maintained 1.5 ata. Steam supply shall be from 20 of 70 auxiliary steam header.

Deaerator pressure during cold/warm/hot startup and during HP-LP bypass shall be decided by Bidder based on minimum Feed Water temperature required by Boiler at Economizer inlet as per Boiler OEM design/standard practice. Please confirm acceptance.

Agreed.

Ensure HP bypass designed to accept continuous spray water at temperature corresponding to all HP heaters out of service and deaerator pegged at 1.5 ata. 45

Section-2 / Chapter-1 / Volume-III

2.16.5

75 of 120 Note: Auxiliary steam Header shall be suitable for steam operating Auxiliary steam header parameters shall be optimized by the bidder as per parameter 16 kg/cm2(a) and 310°C and design shall not be less end consumer requirements. than 19 kg/cm2(a) and 335°C. Please confirm acceptance. The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume Section-1 / Chapter-2 / Volume-III

Clause No. 1.3.1

Page no.

Bid Specification Stipulation

6 of 12 Complete regenerative feed heating system including full capacity drain cooler, minimum four (4) nos. of low pressure heaters, one (1) deaerator and feed storage tank, minimum three (3) nos. of high pressure heaters (HP)…

Statement of Prebid Queries & Clarification i) Bidder shall be allowed select/design the LP heaters with integral drain cooler or with drain cooler installed outside. ii) If LP Heater drain pumps are provided, then there shall not be any drain cooler as no drain cooling zone in these heaters. Please confirm acceptance.

47

Section-2 / Chapter-2 / Volume-III

2.1.3 (i)

Owner's Reply

The provision as per bidding document shall prevail.

4 of 70 For sizing of various auxiliaries in Bidder's scope of supply like Being an EPC tender where Boiler, Turbine including various auxiliaries are BFP, HP-LP Bypass system etc. the Bidder shall therefore in Bidder's scope, BMCR flow will be considered as 102% of TG VWO steam consider BMCR steam flow of 2060 TPH or 102% of turbine VWO flow. steam flow, whichever is higher. Please confirm acceptance. Confirmed.

48

Section-2 / Chapter-2 / Volume-III

2.20

22 of 70 Heat Balance Diagrams: (a) Atleast 693 MW (i.e. atleast 105% of rated load) under rated steam condition at design condenser pressure with zero make up (GUARANTEED OUTPUT & GUARANTEED HEAT RATE). (b) 660 MW output under rated steam conditions at design condenser pressure with zero make-up (GUARANTEED HEAT RATE). (d) 528MW output under turbine throttle inlet steam conditions corresponding to sliding pressure operation and rated steam temperature at design condenser pressure with 0% & 1% makeup. (e) 396MW output under turbine throttle inlet steam conditions di lidi d i d

Bidder understands that for VWO,0%MU and 100%TMCR,0%MU guaranteed heat rate HBD preparations design condenser vacuum arrived based on VWO,1%MU operating condition to be considered. Please confirm bidder understanding. However for part load operating conditions bidder understands that The provision as per corresponding condenser vacuum arrived based on condenser correction bidding document shall curves to be considered for HBD preparations. Please confirm bidder prevail. understanding.

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50

Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Section-2 / Chapter-2 / Volume-III

Clause No. 2.20

2.20.1

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

23 of 70 Heat Balance Diagrams: We understand worst condenser pressure corresponds to Condenser (h) 660MW output under rated steam conditions at worst pressure with maximum CW temp of 36 deg C. condenser pressure with 1% make-up. (k) VWO output under rated steam conditions at worst condenser Please confirm acceptance. pressure with 1% make-up. (n) All HP heaters out of service under rated steam conditions at design & worst condenser pressure with zero percent make up and 1% make-up and rated output

24 of 70 4. Worst pressure in the condenser : 89 mm Hg (a)

Owner's Reply

Confirmed.

We understand worst condenser pressure corresponds to Condenser pressure with maximum CW temp of 36 deg C. Please confirm acceptance. Confirmed.

51

Section-2 / Chapter-2 / Volume-III

2.20.1

There is contradiction in these clauses related to mode of operation. 26 of 70 Note vii) In the sliding pressure mode of operation the throttle pressure will Following has been considered for modified Sliding Pressure Operation: slide down from rated pressure to a value corresponding to 40% of rated pressure. ● 0% to 40% TMCR : Constant Pressure Operation ● 40% to 100% TMCR: Sliding Pressure Operation ● 100% TMCR to VWO : Constant Pressure Operation Please confirm acceptance.

The provision as per bidding document shall prevail. 0% to 35% BMCR Constant pressure. 35% to 90% BMCR slidnign presssiure, 90% to 100%BMCR constant pressure

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52

Section / Part / Chapter / Volume

Clause No.

Section-2 / Chapter-1 / Volume-III

2.1.9

Section-2 / Chapter-2 / Volume-III

3.1 (viii)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

4 of 120 Sliding Pressure Operation from rated pressure down to 35-40% of rated pressure with as well as without any throttle reserve. Modified sliding pressure operation shall comprise of constant pressure operation from rated load to approximately 90% of rated load and then sliding pressure operation down to 40% of rated pressure/load

28 of 70 Maximum oxygen content of condensate leaving the condenser shall be 0.015 CC per litre over the entire load range.

Maximum oxygen recommendation.

content

of

condensate

shall

be

as

per

HEI

Please confirm acceptance. The provision as per bidding document shall prevail.

53

Section-2 / Chapter-2 / Volume-III

3.2 (ix)

29 of 70 Water box & support plates material shall be of carbon steel as per Bidder proposes alternate material as ASTM A 516 GR70 for Water box & ASTM A285 Gr. C/ IS2062 Gr. B and tube plate shall be of carbon tube plate. steel as per ASTM A285 Gr. C. Please confirm acceptance. Agreed.

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Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Clause No.

Page no.

Bid Specification Stipulation

3.3.1 (1) (h)

30 of 70 Temperature rise in circulation water across the condenser: 8°C(Maximum)

Statement of Prebid Queries & Clarification

Owner's Reply

We understand the maximum CW temperature rise specified is for normal operating conditions except HP-LP Bypass operation. Please confirm acceptance. Confirmed.

55

56

Section-2 / Chapter-2 / Volume-III Chapter-8 / Volume-II

Section-2 / Chapter-2 / Volume-III

3.3.1 (1) (l) 3.1 (iv)

3.3.1 (3)

31 of 70 Tube plugging Margin 10%

There is contradition between two clauses regarding plugging margin for Condenser. Bidder will consider 5% tube plugging margin as per refered 5 of 78 The tube plug margin of 5%, as per design condition, shall be clause 3.1 (iv). considered for condenser performance calculation at design condition. Please confirm acceptance.

31 of 70 Water box test pressure 1.5 times the design pressure

The provision as per bidding document shall prevail.

Water box test pressure shall be considered as 1.3 times the design pressure as per HEI. Please confirm acceptance. The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Clause No. 3.7 (vii)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

35 of 70 Hogging operation(at 10 inch(254mm) of Hg(abs) condenser Hogging capacity shall be as per HEI for Surface Condenser. pressure : 500 SCFM (850m3/hr) under standard conditions i.e. 760 mmHg(abs and 21.10C) Please confirm acceptance. The provision as per bidding document shall prevail.

58

59

Section-2 / Chapter-2 / Volume-III

Section-2 / Chapter-2 / Volume-III

3.9 (viii)

3.9 (viii)

37 of 70 (b) Design Head While calculating design head, 10% margin shall be considered over The design head shall be worked out considering minimum 10% corresponding condition deaerator pressure instead of maximum deaerator margin in piping friction for highest condensate flow as at (1) above pressure. and 10% margin over maximum deaerator pressure. Please confirm acceptance.

The provision as per bidding document shall prevail.

3rd pump may come into service during HP-LP bypass operation with turbine 37 of 70 ('e) Other Capabilities (3) 2 pumps shall be capable of handling the flow corresponding to on 40% TMCR load (parallel operation of turbine with Bypass). HP-LP bypass operation with turbine on 40% TMCR load (parallel operation of turbine with Bypass). Please confirm acceptance. The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Clause No. 5.1 (v)

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

42 of 70 Alternatively HP heater drains shall be directly led to deaerator and Alternatively LP heaters drains can be directly led to Condenser as per condenser and alternative LP heater drains shall be directly led to Bidder's practice. condenser in case of increasing level in the heaters. The drains to Please confirm acceptance. the condenser hall be led through flash tanks. The provision as per bidding document shall prevail.

61

Section-2 / Chapter-2 / Volume-III

5.1 (xxii)

43 of 70 Provide sentinel relief valve on tube side. Relief valve on shell side sized to pass flow from two ruptured tubes (four open ends) or 10% of water flow corresponding to VWO condition with 1% make up and design condenser pressure at 10% accumulation, whichever is higher and set to open at heater shell design pressure.

BIDDER wishes to clarify that for arriving feedwater heater shell side relief valve capacity as per HEI requirement. Shell side relief shall be sized for 10% of the feed water flow, or Flow based on the clean rupture of one heater tube resulting in two (2) open ends discharging , whichever is greater, at 10% accumulation. Please confirm acceptance.

62

Section-2 / Chapter-2 / Volume-III

5.3.1 (viii)-)'c)

The provision as per bidding document shall prevail.

45 of 70 1 pump shall be capable of handling the flow corresponding to Unit We understand worst condenser pressure corresponds to Condenser EMCR, all HP heaters out, 1% make-up and worst condenser pressure with maximum CW temp of 36 deg C. pressure at 47.5 Hz. Please confirm acceptance. Confirmed.

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64

Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Section-2 / Chapter-2 / Volume-III

Clause No. 5.4 (xi)

6.1

Page no.

Bid Specification Stipulation

48 of 70 Deaerator operation will be floating pressure type. Pegging pressure at 3.5 ata during HP-LP bypass operation, major load rejection, turbine trip and low loads when extraction steam pressure is less than 3.5 ata. During cold start-up the deaerator pressure shall be maintained at 1.5 ata with steam from auxiliary steam header. During hot and warm startup, if boiler startup drain circulation pumps are in service, deaerator pressure shall be maintained at 3.5 ata. In case startup drain circulation pumps are not in service and startup drains are routed through condenser, deaerator pressure shall be maintained 1.5 ata.

Statement of Prebid Queries & Clarification

Owner's Reply

Deaerator pressure during cold/warm/hot startup and during HP-LP bypass shall be decided by Bidder based on minimum Feed Water temperature required by Boiler at Economizer inlet as per Boiler OEM design/standard practice. Please confirm acceptance.

Confirmed.

50 of 70 The flash tanks shall be provided receive the drains and safety LP drain flash tank is not envisaged as per Bidder's practice as LP heaters valve connections from various equipment’s and systems. These, drain will be directly led to Condenser. as a minimum, shall include Unit flash tank, turbine drain flash Please confirm acceptance. tanks (left & right), HP drain flash tank and LP drain flash tank. The provision as per bidding document shall prevail.

65

Section-2 / Chapter-2 / Volume-III

7.2

Attached is Interpretation to PG-61.5, Feed Water Supply for a Steam 52 of 70 BFP Emergency Point Design Criteria: Two turbine driven feed pumps to be capable of generating the Generator With No Fixed Water Level. This was published in ASME website in July 2014. discharge pressure not less than 3% over steam generator highest safety valve set pressure corresponding to 105% of BMCR flow. The pressure drop between bidder terminal points & highest The provision as per BPVC-Isafety valve set pressure shall be intimated to bidder at later stage. Interp_Stndbidding document shall 63 2014 Jul As per Interpretation to PG-61.5, it is not required to size the BFP for prevail. emergency point mentioned in tender. Hence, Bidder would like to consider the emergency point for BFP capability as flow corresponding to BMCR condition and head corresponding to i t d t i i l t (d i )

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

66

Section-2 / Chapter-2 / Volume-III

7.2

52 of 70 MDBF Design Criteria: We understand BFP shall be capable to handle flow corresponding to All conditions prescribed in column for TDBFP shall be required to 100%TMCR at 47.5 Hz frequency. be met by MDBFP as applicable. The head developed by MDBFP shall be calculated in the same Please clarify. way as done for TDBFPs for all the conditions so that TDBFPs and The provision as per MDBFPs can be operated in parallel bidding document shall prevail. The conditions shall be met by MDBFP at 47.5 Hz frequency

67

Section-2 / Chapter-2 / Volume-III

7.2

53 of 70 Discharge pressure for both MDBFP & TDBFP: Not less than 400 Kg/Cm2 (a) at terminal point.

68

Section-2 / Chapter-2 / Volume-III

7.2

Section-2 / Chapter-1 / Volume-III

2.7.3 -4(b)

53 of 70 Rated discharge flow through interstage bleed flow from TDBFP There is contradition between two clauses regarding attemperation flow as for reheater attemperation. 140 TPH is much higher than 3% of steam flow at HPT exhaust. Not less than 140 TPH(tentative) Also, please clarify whether 140 TPH is combined flow of two TDBFP or 23 of 120 Reheater attemperation : 3% (maximum) of steam flow at HPT single TDBFP. exhaust to boiler at emergency condition (0% under normal Being an EPC tender, Rated discharge flow through interstage bleed flow operating conditions). from TDBFP for reheater attemperation shall be as per Boiler design requirements.

Please clarify the specified discharge pressure is at which condition. As per our understanding, Maximum discharge pressure shall be decided based on head corresponding to Boiler design pressure inline with tender technical specifications. Worst condition - 400 kg/cm2 Please confirm acceptance. or Based on boiler design pressure head, whichever is more.

The provision as per bidding document shall prevail. 140 TPH is combined flow of two TDBFP.

Please confirm acceptance.

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Section / Part / Chapter / Volume Section-2 / Chapter-2 / Volume-III

Clause No. 7.3.1 (xvi)

Page no.

Bid Specification Stipulation

55 of 70 TDH per stage TDH per stage for the main pump shall not exceed 670 mwc

Statement of Prebid Queries & Clarification

Owner's Reply

TDH per stage shall be as per OEM design. Higher TDH per stage limit upto 800 mwc may be allowed inline with recent NTPC practice. Please confirm acceptance. Confirmed.

70

Section-2 / Chapter-2 / Volume-III

8.3.2 (i)

64 of 70 Noise Level For HP-LP Bypass, safety valves and intermittently operating Pressure Safety valves and associated vent pipes for which it shall not control valves higher noise level upto 115 dBA shall be allowed. exceed 105 dBA. Please confirm acceptance. The provision as per bidding document shall prevail.

71

Chapter-26 / Volume-III

26.1.2 (i)

2 of 26 ('e) HP/LP bypass upstream : 76 m/s

For HP-LP bypass upstream, higher velocity limit (100m/s) shall be allowed as this will not be in continuous operation. 100 m/s is also inline to NTPC's latest practice. Please confirm acceptance.

The provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume

Clause No.

72

Chapter-26 / Volume-III

26.1.2 (i)

Page no.

Bid Specification Stipulation

2 of 26 BFP Exhaust line steam velocity limit

Statement of Prebid Queries & Clarification

Owner's Reply

Velocity limit in the BFPT exhaust duct line have been considered as approx. 125 m/s. Please confirm acceptance. Confirmed.

73

Chapter-26 / Volume-III

26.1.3 (d)

3 of 26 The design pressure of boiler feed discharge piping at downstream of block valve on FRS shall be 105% of pressure corresponding to emergency point of BFP operation. However bidder to provide suitable pressure relieving device inline with IBR reg. 520 so that these piping or equipment’s/valves/instruments connected to feed water discharge piping system are not subjected to shut-off head.

Piping downstream of FRS will not be subjected to BFP emergency point. FRS downstream piping design pressure shall be same as HP heaters tube side design pressure considering BFP discharge pressure corresponding to lowest safety valve set pressure. IBR reg 520 requirement will be complied. Hence, FRS downstream piping can be designed based on BFP discharge pressure corresponding to Boiler lowest safety valve set pressure.

Confirmed.

Please confirm acceptance.

74

Volume VII-TDMechanical

Dwg No. 11111-0600 (Flow Diagram of Condensate System)

1 of 1

As per the tender drawing individual CEP recirculation line is BIDDER envisage to use common recirculation line for all three pumps shall routed to the condenser. be provided after gland Steam Condenser and will be sized considering minimum recirculation requirement of both GSC as well as CEPs. Please confirm acceptance.

The provision as per bidding document shall prevail.

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76

Section / Part / Chapter / Volume Volume VII-TDMechanical

Section-1 / Chapter-2 / Volume-III

Volume VII-TDMechanical

77

Volume VII-TDMechanical

Clause No.

Page no.

Dwg No. 11111-0500 (Flow Diagram of Heater Vent & Drain)

1 of 1

1.6

Dwg No. 11111-0600 (Flow Diagram of Condensate S No. t 111) Dwg 11-0700 (Flow Diagram of Feed Water System)

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

As per the tender Heaters Vents lines are connected to Flash Bidders shall be given flexibility to connect heaters vents to Deaerator / Tanks. Condenser as per Bidder's practice.

Please confirm acceptance.

7 of 12 Deaerator level control station for condensate water flow control, consisting of the following for each unit: 1) 2 x 100% capacity pneumatically operated condensate control valve. 2) One motor operated gate valve on upstream and one manual operated gate valve on downstream of each condensate control valve. 3) One motor operated inching valve in bypass line of above condensate control station. 1 of 1

There is contradiction between Deaerator Level Control Station Configuration specified in Specification and Condensate System flow diagram. As indicated in the flow diagram, many MOVs are not required (like MOVs on upstream and downstream of bypass MOV and MOV on the downstream of Control Valve).

1 of 1

As per Bidder’s practice, Motor Operated integral bypass valve for 2X50% isolation valve (parallel to 30% FCV in Flow Control Station) is not required. Manual integral bypass valve shall be provided.

The provision as per bidding document shall prevail.

The provision as per We will follow Deaerator Level Control station Configuration as per Cl. 1.6 of bidding document shall prevail. Ch-2, Sec-1, Vol-III. Please Confirm.

Please confirm acceptance.

The provision as per bidding document shall prevail.

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79

80

D

Section / Part / Chapter / Volume Volume VII, Tender Drawings Mech Layouts

Volume VII, Tender Drawings Mech Layouts

Volume-III, Chapter-2, Section 2

Clause No. TG Building Floor Plan

TG Building Floor Plan

2.2

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

111-210200 / 111-210300 / 111-210400 / 111-21- -0600

Bidder understands that, Power house building width of AB & BC bay shown is indicative & same can be resized based on Bidder's proposed layout and requirement.

111-210200 / 111-210300 / 111-210400 / 111-21- -0600

Bidder understands that Length of Power house building and Grid interspacing is indicative, same can be resized based on layout requirement.

24 of 70 (u) Steam Generator output corresponding to BMCR flow under rated steam condition, turbine under VWO operation, worst condenser pressure 1% make up at rated feed water temperature. Difference of BMCR flow and VWO steam flow through turbine shall be assumed to be drawn off from Main steam line. Same quantity of flow to be added to condenser as additional make up. (GURANTEED STEAM GENERATOR CAPACITY)

Feed water temperature at BMCR condition shall be as optimized by the bidder instead of rated feedwater temperature. Please confirm.

Owner's Reply

Please confirm acceptance. Confirmed.

Please confirm acceptance. Confirmed.

Condenser pressure at BMCR condition will be design condenser pressure instead of worst condenser pressure. Please confirm.

Agreed. Design condenser pressure.

ESP & FGD_Mech

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1

2

3

4

5

Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.5 1)

Sheet 6 2 sets of dewatering equipments i.e. primary dewatering and of 54 secondary dewatering.

We propose to bleed-out waste water from the overflow stream of (primary) hydro-cyclone to avoid negative process performance impact of accumulated impurities in the absorbent slurry. Therefore secondary hydro-cyclones will Bidder to submit scheme not be provided as per our collaborator standard practice description alongwith bid. Kindly confirm.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.5

Sheet 6 1) The Owner envisages gypsum dewatering system for each unit. of 54 The dewatering system shall receive the gypsum slurry from the absorber through 2x100% Gypsum bleed pump and shall comprise of 2 sets of dewatering equipments i.e. primary dewatering and secondary dewatering.

We propose to bleed-out waste water from the overflow stream of (primary) hydro-cyclone to avoid negative process performance impact of accumulated impurities in the absorbent slurry. Therefore secondary hydro-cyclones will not be provided as per our collaborator standard practice Kindly confirm. Bidder to submit scheme description alongwith bid.

6) Secondary stage consisting of two (2) Secondary hydro-cyclone feed tanks. Three are suitable for handling / dewatering of both units. of 2 sets of dewatering equipments i.e. primary dewatering and secondary dewatering. 6) Secondary stage consisting of two (2) Secondary hydro-cyclone We propose to bleed-out waste water from the overflow stream of (primary) feed tanks. Three are suitable for handling / dewatering of both hydro-cyclone to avoid negative process performance impact of accumulated units. impurities in the absorbent slurry. Therefore secondary hydro-cyclones will Bidder to submit scheme not be provided as per our collaborator standard practice description alongwith bid. Kindly confirm.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.5 6)

Sheet 7 of 54

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.5 8)

Sheet 7 of 54

8) The overflow from each primary set of hydro-cyclones shall be We propose to bleed-out waste water from the overflow stream of (primary) taken to individual secondary waste water hydro-cyclone feed tank hydro-cyclone to avoid negative process performance impact of accumulated provided with Agitator(s). impurities in the absorbent slurry. Therefore secondary hydro-cyclones will Bidder to submit scheme not be provided as per our collaborator standard practice description alongwith bid. Kindly confirm.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.5

Sheet 7 of 54

8) The overflow from each primary set of hydro-cyclones shall be Overflow from primary hydrocyclone shall be taken to Waste water tank as taken to individual secondary waste water hydro-cyclone feed tank our collaborator don't recommend secondary hydrocyclone in order to provided with Agitator(s). maintain higher level of gypsum quality . Kindly confirm the acceptance. 9) The under flow from the secondary hydro-cyclones shall be taken to reclaim water tanks provided with Agitator(s). Reclaim water pumps shall be provided to recycle the water to the each absorber.

Bidder to submit scheme description alongwith bid.

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6.2.9

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Sheet 13 Noise level: of 54 The equivalent weighted average of sound level measured at a distance of 1.5 m above floor level in each elevation and one meter horizontally from the base of any equipments furnished and installed under these specifications, expressed in decibel to a reference of 0.0002 microbar, shall not exceed 85 dB(A), except for: a) Wet Mill <90 dB(A) & b) Crusher < 102 dB(A).

Noise limitation will be approx. 110 dBA & 120 dBA for Wet Ball Mill & Crusher respectively measured at 1.5 m distance from the surface of the equipment as per information provided by OEM .Kindly confirm the acceptance.

6.1.10 1)

Sheet 9 of 54

One (1) number passenger cum goods elevator for each Absorber and one (1) passenger cum goods elevator for limestone bunker/silos upto top level, each of minimum apacity of 1088 kgs in FGD system for easy access & movement of man/materials as shown in layout shall be provided.

Since our offered absorber (JBR) shall be significantly shorter in height than conventional spray tower type FGD we have not considered any elevator for the same. This is in line with requirement of other major power utilities in India.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.4 (b)

Sheet 5 of 54

Multi louver damper quick opening pneumatic/motor operated shall A common chimney has been specified for the plant with/without FGD be provided at following locations for each unit. operation. As per our past experience, multilouver damper is not necessary i) Clean gas duct at outlet of each absorber. at outlet of absorber since gate damper is already provided. ii) FGD bypass clean flue gas duct.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.4 (k)

Sheet 6 of 54

All pumps & oxidation blowers/compressor shall be in straight line

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.11

Volume III : Ch 6 : Flue Gas Desulphurisation System

6.1.2

Sheet 9 of 54

Bidder shall provide buildings for oxidation blowers/compressors

Sheet 2 of 54

FGD system shall be installed downstream of Induced Draft fans. Gas from ID fan discharge duct shall be taken directly to the absorber.

Pumps & compressors shall be placed as per requirement in process flow & layout. However items placed in one location may be placed in straight line subject to availability of spaces.

Oxidation blower, suitable for outdoor condition, will be installed under flue gas duct as per standard practice of our collaborator. Hence building is not envisaged.

Request you to modify clause as follows: "FGD system shall be installed downstream of Induced Draft fans. Gas from ID fan discharge duct shall be taken directly to the absorber. In case bidder offers Jet Bubbling Absorber, separate booster fan may be provided as per standard practice."

Owner's Reply

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

Agreed.

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

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6.1.11

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.2.5 4)

Page no. Sheet 9 of 54

Bid Specification Stipulation Bidder shall provide buildings for Limestone grinding System, slurry recirculation pumps & oxidation blowers/compressors, Gypsum Dewatering system, FGD control room, electrical panel room, control cubical & Analyser room.

Statement of Prebid Queries & Clarification Buildings for oxidation blower and cooling pumps are not envisaged as per standard practice of collaborator.

Sheet 12 4) The FGD and the auxiliary’s facilities shall be suitable for Please define "unlimited operation" of 54 unlimited operation with all transients and at any load point between the minimum and maximum load point of the Steam Generator. Further, the FGD plant shall be suitable for an unlimited operation at any pollutant concentrations between minimum and maximum without exceeding the guaranteed figure as specified elsewhere in the specification.

2.12.4. (iii) Volume III Mechanical Works Ch 1: SG & Auxiliaries Section 2 : Design Basis of SG & Auxiliaries and SCR Volume III : 6.5.6 Mechanical Works 6) Ch 6 : Flue Gas Desulphurisation System

Sheet | Cooling air circulation to be provided across main bearing 57 of 120

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.6 11)

Sheet 25 The absorber vessel shall be made of minimum 7 mm thick carbon Bidder proposes Flake Glass lining (FlRP) on the inside surface of the of 54 steel. The absorber oxidation tank, absorber tower & absorber absorber vessel, oxidation tank and outlet duct as it is proven for better life outlet duct shall be provided with 2 mm (minimum) thickness lining and reliability as per our collaborator's global experience. / cladding / wall paper of Alloy C276 / Alloy 59 or better material with the exception of use of rubber material.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.6 13)

Owner's Reply

The Provision as per bidding document shall prevail.

Without any restrictions on load range and period of operation.

This requirement shall be finalized as per OEM standard practice during detail engineering. Agreed.

Sheet 25 Three stage chevron type Mist Eliminators (ME) made of As per our offered technology, we envisage requirement of two stage mist of 54 polysulfone or Polypropylene or stainless steel shall be provided at eliminator. Kindly confirm the acceptance. the exit of the absorber.

Sheet 25 All internal members shall be lined with minimum 2 mm Alloy of 54 59/C276. All metallic fasteners which are provided inside the absorber/absorber wet-dry interface ducting shall be of Alloy 59/C276.

All internal members and metallic fasteners including struts in Gas Cooler and JBR shall be lined with FlRP as per collaborator standard practice and global experience. Kindly confirm the acceptance.

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

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Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.6 14)

Sheet 25 The absorber wet-dry interface shall be made of Alloy C276 / Alloy of 54 59 of minimum 6 mm thickness.

Bidder requests to modify the clause as follows: 'The absorber wet-dry interface shall be made of Alloy C276 / Alloy 59 of minimum 6 mm thickness. Additionally Flake Glass Lining on Mild Steel shall also be acceptable in case of proven experience.'

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.6 15)

Sheet 25 The other bridges (supports) shall be lined with minimum 2 mm of 54 Alloy 59/ C276.

All bridges (supports) in Gas Cooler and JBR shall be lined with FlRP as per collaborator standard practice and global experience. Kindly confirm the acceptance.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.6.5 1) ii)

Sheet 30 Wet Ball Mill: Flow: Atleast 120% of limestone requirement of one of 54 absorber at Design point

Reagent slurry pump flow is of 110% capacity. Hence, Wet ball mill capacity should be 110%. Please confirm

6.6.5 1) iv)

Sheet 30 Limestone bond index (kWh/sh.T) 13 (min) of 54

Bidder understand: Limestone bond index: (kWh/Metric Ton) 13 (min). Please confirm

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Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.6.7 1) v)

Sheet 32 Limestone Slurry Pumps: of 54 Solids Concentration: Max. 20% by weight or actual as per suppliers practice, whichever is minimum

As per industry practice solid concentration may go up to 30% by wt. in Limestone Slurry Pumps. Hence kindly modify the clause accordingly.

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Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.7.3 2) c)

Sheet 33 Gypsum Purity 90% (minimum) not less than 84% for of 54 guaranteed point limestone analysis

Bidder understands gypsum purity shall be 84% for the guarantee point. Please confirm.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.7.3 4)

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Owner's Reply

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

The Provision as per bidding document shall prevail.

Confirmed.

The Provision as per bidding document shall prevail.

Confirmed.

Sheet 33 The filter cloth shall be polyester or polypropylene as per the proven design of the supplier and shall be guaranteed for a of 54 minimum life of not less than 7000 hrs.

Typical guaranteed life of filter cloth by OEM is not more than 4,000 hrs. The Provision as per bidding document shall prevail.

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Owner's Reply

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.7.3 6)

Sheet 34 In case the contractor offers design with an underlying belt for of 54 carrying the filter cloth, the same shall be endless factory vulcanized rubber belts.

The size of Vacuum belt filter will decide the extent of modularization and hence the final assembly requirement at site. This will in turn govern the requirement of site joint (vulcanized) for rubber belts. Hence same shall be finalized during detail engineering.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.7.3 4)

Sheet 33 The complete frame of filter and all parts in contact gypsum shall of 54 be made of corrosion resistant material or shall be provided with corrosion resistant liners of proven design.

Bidder proposes CS body with epoxy paint for the complete frame which is also followed as standard by vendors. However, if different material is required the same needs to be specifically mentioned.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.8.2 4)

Sheet 38 The pump shall be capable of pumping of reclaim water with solid Sump pumps handling slurry shall be provided with strainers and hence will of 54 concentration upto 10% & particle lumps of 6-7mm. Sump pumps never handle particle size of 6-7 mm. Please clarify the requirement handling slurry shall be designed with a maximum concentration of 30% solid by weight.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.8.4 5)

Sheet 39 The material for the shaft (which is continuously in contact with Our standard agitator material (shaft and blades) shall be rubber lined carbon of 54 slurry) and agitator blades of the Absorber Agitators shall be made steel as per standard practice and collaborator's global experience. Please with Alloy 926 or better material. For Agitators in other tanks, confirm. The Provision as per agitator blades shall be made with Alloy 926 or better material & bidding document shall shaft can be rubber lined with separate rubber layer for corrosion & prevail. erosion protection.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.6 2)

Sheet 7 of 54

6.7.7 2)

Sheet 36 The bidder shall provide 2x 100% pumps to pump back the slurry of 54 from the sump back to absorber in maximum time of 8 hrs. Each pump shall be suitable for two units.

The Bidder shall provide 2x100% slurry pumps for pumping the slurry back to each absorber in 12 hrs (max.).

The Provision as per bidding document shall prevail.

Agreed.

Bidder to indicate the maximum possible particle size.

Discrepancy is found in the pumping time to absorber. Kindly clarify the same.

Bidder to follow clause 6.7.72 sheet 36 of 54.

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Section / Part / Chapter / Volume Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Clause No. 6.8.3

30

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Sheet 39 Slurry & Process Water Tanks Please note that these tanks are rubber lined. Hence additional corrosion of 54 allowance of 3 mm is not required. Please confirm. All the slurry tanks (slurry tank, reclaim water tanks, secondary hydro cyclone feed tank, vacuum receiver tank, waste water tank, lime neutralization tank etc.) shall be designed, fabricated, erected and tested in accordance with the IS:803, latest edition. Additional Corrosion allowance of 3mm on the minimum tank shell thickness as calculated by IS: 803, latest edition shall be provided by the Bidder. Tanks shall be made from IS: 2062 quality mild steel plates of tested quality. The tanks shall be of welded construction. Interior surface of the tanks shall lined with replaceable rubber lining and the outside surface shall be coated with paint as approved by the Owner. The Tanks shall be provided with drain, manholes, over flow & inlet level control valves etc.

Owner's Reply

The Provision as per bidding document shall prevail.

6.4.1.5

31

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Sheet 15 The duct from Absorber outlet to bypass duct shall be made of of 54 Carbon steel of minimum 7mm thickness with 2 mm (minimum) thickness lining/cladding/wallpaper of 2 mm(minimum)thickness of alloy 276/ Alloy-59 or better material.

The duct from Absorber outlet to bypass duct shall be made of Carbon steel of minimum 7mm thickness with 2 mm (minimum) thick FlRP lining as per our The Provision as per collaborator proven practice. Please confirm. bidding document shall prevail.

6.8.5 3)

Sheet 40 ...Motorized actuators shall be provided for valves requiring of 54 frequent operation as indicated in the relevant scheme.

Bidder proposes to use Motorized / Pneumatic actuators for valves requiring frequent operation as per standard industry practice.

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Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.9.1 17)

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Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Sheet 43 Inter-connecting pipes/cables between various facilities of FGD of 54 plant shall be routed on the steel trestles. The clear head room for the same shall be minimum 8 M.

Bidder proposes that the clear head room for the inter-connecting pipe/cable trestle between various facilities of FGD shall be 3 meter except road The Provision as per crossings where clear head room shall be 8 meter as per tender requirement. bidding document shall prevail.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.1

Sheet 22 B. Jet Bubbling Absorber (If offered) of 54 .......................Further, 2x 100% Cooling Pumps instead of Slurry Recirculation shall be provided. The spray headers & piping for cooling pump discharge shall be made of Alloy 59 or C276 and nozzles shall be made of Silicon Carbide or ceramic or equivalent having a minimum guaranteed life of 20,000hrs....

Bidder envisages that the slurry spray headers within the gas cooler shall be made of same material as that of slurry spray header appliable for spray tower. The piping outside the gas cooler, which is not in contact with hot flue gas shall be FRP or CS with rubber lining.

34

The Provision as per bidding document shall prevail.

Agreed.

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Owner's Reply

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.8.1 4)

Sheet 37 All the slurry pumps shall be provided with motorized suction and of 54 discharge valves. In addition, flushing water lines with motorized valves shall be provided for each pump for automatic flushing of the pump after each shut down…

Bidder proposes to modify this clause as "All the slurry pumps shall be provided with motorized / pneumatic suction and discharge valves. In addition, flushing water lines with motorized / pneumatic valves shall be provided for each pump for automatic flushing of the pump after each shut down..."

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.1

Sheet 22 B. Jet Bubbling Absorber (If offered) of 54 …………………………...The Cooling Pumps shall be installed inside a building....

The Cooling Pumps shall be installed below the mist eliminator as per standard practice of collaborator. Hence, no separate building is envisaged.

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.5.6 6)

Sheet 24 The ME system shall be equipped with washing and drain of 54 provisions, ......The mist eliminator wash piping/header shall be constructed of rubber lined carbon steel or glass fiber reinforced plastics....

Bidder envisages that the carbon steel pipe shall be selected for outside pipe up to the nozzles at mist eliminator casing. Inside the mist eliminator casing , piping header shall be of PP/PVC in addition to FRP/CSRL The Provision as Agreed. per bidding document shall prevail.

Sheet 5 of 7

Please provide the HCl & HF concentration in coal analysis.

Volume II General & Schedules Ch 2 : Project Information

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.7.3

Appendix – II: Coal Quality Parameters

The Provision as per bidding document shall prevail.

Based on arrangement will be decided during detail engineering.

HCI & HF are in traces. Bidder may collect sampe of coal during execution of project during detail engineering.

Sheet 33 Gypsum Purity 90% (minimum) not less than 84% for guaranteed of 54 point limestone analysis

Please provide Limestone analysis. Reffer adenddum No.- 01

Volume III, Ch 1: SG & 2.12.1 i).3.i) Auxiliaries, Section 2 : Design Basis of SG & Auxiliaries and SCR

55 of 120 Pressure drop through FGD - 200 mm WC

Volume II, Ch 8 : Functional Guarantee & Liquidated Damages

26 of 78

4.1.2

Contractor’s design shall ensure that the SO2 removal efficiency from FGD shall not be more than 80 mg/NM3 (6% O2 dry basis) under guarantee point condition.

Refered clause does not specify whether pressure has to be considered at FGD Design Point or FGD Guarantee Point. Bidder understands that the limit of 200mm pressure drop referred herein is to be considered at FGD Design Point. In case of higher pressure drop, bidder shall provide booster fan to meet the requirement. Kindly confirm. Tender stipulates guarantee on flue gas outlet SO2 content. SO2 removal efficiency is a derived value based on input parameters calculated based on boiler design which may vary from bidder to bidder. Hence we request to modify rejection criteria based on outlet SO2 emmission instead of SO2

Bidder understanding is correct. However, Booster Fan arrangement is not preferred.

The provision as per

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Section / Part / Chapter / Volume

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Bid Specification Stipulation

Volume I, SECTION – III BDS

10.1 (3) (e)

53 of 63

Bids guarantee/offering worse value than that specified in the technical specification (Clause 6.3 of Chapter 6, Volume III) for SO2 removal efficiency may not be considered for evaluation and may be rejected.

Volume II, Ch 8 : Functional Guarantee & Liquidated Damages

3.10

20 of 78

AUXILIARY POWER CONSUMPTION

FGD is not covered under said clause. Please confirm following: 1) FGD to be considered under unit or station auxillary power consumption. 2) Please specify duty factor for FGD components if any.

Volume II General & Schedules, Ch 4 : Provenness

4.24

24 of 40

Provenness criteria for critical equipment, auxiliaries, systems and bought out items for Flue Gas Desulphurisation System: ….

Bidding of FGD systems of more than 25 GW has been recently concluded which shall be followed by multi fold ordering of FGD equipment. This will necessitate large vendor base. Hence major power utilities like NTPC have allowed Indian vendors to supply locally made equipment for their projects based on Technology Licensing Agreement (TLA) with their principals or international OEMs that have supplied similar equipment. On similar lines we request you to amend requirement of "sourcing the first equipment from qualified manufacturer" and allow supply of all equipment from local manufacturers based on TLA. SImilarly DJU is also not envisaged for submission as excerpt of TLA may be submitted if required. This is also in spirit of Make in India policy.

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Statement of Prebid Queries & Clarification y j removal efficiency.

6.1.3 Vol II B, Technical Specification Mechanical, Chapter-6 6.1.3 Vol II B, Technical Specification Mechanical, Chapter-6 6.1.3 Vol II B, Technical Specification Mechanical, Chapter-6 Vol II B, Technical 6.1.3 Specification Mechanical, Chapter-6

Owner's Reply The provision as per bidding specification shall prevail.

FGD is a part of Boiler Auxiliary. Hence, FGD is to be considered under unit. The duty factor for FGD is 1.0.

The Provision as per bidding document shall prevail. However, TLA will be reviewed during detail engineering for consideration, if required.

4 of 54 limestone handling system technical specification and process flow Bidder has not received limestone handling system process flow diagram and Bidder to submit their specification & process diagram not received along with tender documents. technical specification along with the tender documents. Bidder request flow diagram for owner to furnish the same. Limestone Handling System for review. 4 of 54 1. Truck weigh bridge - to weigh incoming truckscarying limestone Owner is requested to furnish the capacity of weigh bridge to be considered Refer Chapter 31-31.0, for limestone handling system. 31.2 4 of 54 2. Front end loader - To feed limestone from stockpile into feed hopper.

Owner is requested to furnish the capacity of the front end loader for limestone handling system.

4 of 54 3. Bull dozer - For stockpile formation/management of stockpile in limestone shed/feed limestone from stock pile into feed hopper.

Owner is requested to furnish the capacity of Bull dozer for limestone handling system.

Provision of Front end loader has been deleted. Bull Dozer in scope of Owner.

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Statement of Prebid Queries & Clarification

Vol II B, Technical 6.1.3 Specification Mechanical, Chapter-6

4 of 54 5. Belt Conveyors - To transport Crushed Limestone from Storage area to Silo

Owner is requested to confirm the rated capacity of limestone handling system from limestone storage shed to the day storage silo.

Vol II B, Technical 6.1.3 Specification Mechanical, Chapter-6

4 of 54 14. Crusher - Necessary RCC Deck, GERB Make Vibration Isolation System along with temperature detection system & vibration monitoring system shall be --

Owner is requested to furnish the capacity of the limestone crushing unit. Also furnish the location of the limestone crusher and its auxilieries.

-Vol II B, Technical Specification Mechanical, Chapter-6 Vol II B, Technical -Specification Mechanical, Chapter-6 Vol II B, Technical -Specification Mechanical, Chapter-6

Vol VI / Chapter 05

5.12

Vol VI / Chapter 12

12.5.1

Vol VI / Chapter 12

12.5.1

54

Vol VI / Chapter 12 55

Page no.

12.5.1

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Capacity of limestone storage and gypsum stoarge area required.

--

Owner is requested to furnish the capacity of gypsum handling system from vacuum belt filter outlet to gypsum storage shed. in the absence of input, bidder request owner to furnish the storage capacity of limestone storage area and gypsum storage area in terms of total nos. of day storage requirement. Owner is requested to provide following details for limestone handling systema nd gypsum handling system design. 1. Voumetric and structural density of limestone and gypsum 2. Angle of repose for limestone and gypsum 3. limestone storage dyke max. height to be considered 4. sieve analysis of limestone as received

4 of 4

For preliminary geotechnical investigation report refer Annexure – I As mentioned preliminary geotechnical investigation is not available in the tender document. Bidder requests owner to provide the same. 6 of 22 The liner shall be of corrosion resistant steel type “COR-TEN B” of Two clauses are contradictory. Kindly confirm the MOC of the Chimney flue minimum 10 mm thick. liners. Bidder request to owner to also provide option of 'Flake Glass Lining on Mild 7 of 22 The chimney Flue liner cladding shall be made of 2 mm THK Steel' in addition to liner MOC mentioned. Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achive the requiality as per ASTM-B 898-11. Alternately contractor may provide Borosilicate Glass Block lining system. 6 of 22 Top 10m length or length equal to 2 times flue diameter whichever is larger shall be provided…

As per standard practice followed by major power utilities including NTPC, bidder requests owner to modify clause as below: "Top 10 m length or length equal to 1 times flue diameter whichever is larger shall be provided…"

Owner's Reply Lime handling plant shall be designed for rated capacity of 100 TPH. One (1) working+ One (1) standby stream to to be provided. Crusher capacity for lime stone slurry preparation shall be 120% of rated capacity. Gypsum handling capacity shall be of 100 TPH. 15 days storage required for gypsum storage.

Shall be decided during detail engineering stage

Will be provided. Please refer Addendum.

Bidder to comply with stipulation of technical specification.

Bidder to comply with stipulation of technical specification.

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Section / Part / Chapter / Volume Vol VI / Chapter 07

Clause No. 7.1

Page no. 1 of 1

56

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Complete hopper including vertical and conical portion of bunker in This clause is in contradiction with Clause 6.6.2 of Volume V-III, Chapter 6, mill building shall be provided with lining of atleast 4 mm thick SS Sheet 29 of 54, wherein it is mentioned that "The storage silos and hopper plate grade SS 316L . cones shall be fabricated of minimum 10 mm thick carbon steel with a SS lining of SS304 (4 mm minimum)". Kindly clarify the lining material. Also bidder envisages lining requirement only in conical portion of silo.

Owner's Reply

Lining material: Specification as per Vol.VI, Clause 7.1 i.e SS:316L to be followed. Lining to be provided both in vertical & conical portion.

Vol VI / Chapter 11

11.0

1 of 16

Description Of Buildings, Structures And Other Facilities

In line with the decription of structural configuration and other building details provided for structures in the sub-clauses, kindly provide the description of buildings for Limestone Crusher house, Limestone slurry preparation Reffer addendum no.-01. building, Gypsum dewatering building and Gypsum storage shed.

Vol III / Chapter 6

6.6.1

28 of 54

A limestone and slurry preparation system is envisaged for both units. Bidder shall supply wet limestone grinding and slurry preparation system complete with all auxiliaries and slurry storage tank of proven design.

Kindly confirm the number of silos required in Limestone slurry preparation building.

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12.5.1

59

Sheet | 6 The liner shall be of corrosion resistant steel type “COR-TEN B” of of 22 minimum 10 mm thick. Top 10m length or length equal to 2 times flue diameter whichever is larger shall be provided using material confirming to AISI:316L or BS:1449. The liner shall be supported atleast at five different levels, and restrained laterally at several levels, with a small length at the bottom near breach elevation supported from the bottom with a suitable expansion compensator in between.

2 Nos. of Silos.

The Bidder understands that AISI: 316L is not a suitable material for Wet Stack operations as per EPRI guidelines, therefore top liner shall also be made of either of the following options: 1) 2mm thick Ti + 8mm Thick MS 2) 50mm Thick Borosilicate + 8mm Thick MS

Bidder to comply with stipulation of technical specification

Please confirm.

VOL VI/ Chapter 12

60

12.5.2

Sheet | 7 The flue diameter shall be so sized to ensure that the flue gas exit of 22 velocity is of the order of 20 to 25 meters/second at the normal continuous operating load. It should be ensured that the flue gas exit velocity at the lowest continuous unit load is high enough (of the order of 15 meters/second) to enable adequate dispersion of the flue gases.

As per the Table 2-1 of EPRI guidelines wet stack shall be design as per the following criteria: 1. for Borosilicate lining gas velocity shall be limited to 18.3m/s. 2. for TI Coating / FlRP lining gas velocity shall be limited to 16.8m/s. Therefore for liner sizing same criteria must be utilized.

Bidder to comply with stipulation of technical specification

Kindly confirm.

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Section / Part / Chapter / Volume VOL VI/ Chapter 12

Clause No. 12.1

61

VOL VI/ Chapter 12

12.6

62

VOL VI/ Chapter 12

12.6

63

Page no.

Bid Specification Stipulation

Sheet | The plate thickness of the ducts shall be arrived at from minimum 11 of 22 (i.e. codal) requirements, structural considerations and corrosion allowances. Material of construction shall be COR-TEN steel conforming to IS:2062. Minimum thickness shall be 10 mm.

Sheet | 7 The flue shall be insulated externally. The insulation shall be semiof 22 rigid, resin bonded type, in the form of slabs and shall conform to IS:8183. Blanket type insulation shall not be used. The density of insulation shall not be less than 100 kg/cum for resin bonded rock wool. The coeffient thermal conductivity of insulation shall be 0.52mW / cm/o c at a mean temperature of 100oC. I

Statement of Prebid Queries & Clarification The bidder would like to propose option of 2mm thick FlRP + 8mm Thick MS as an alternative to COR-TEN lining: Please confirm.

Owner's Reply

Bidder to comply with stipulation of technical specification

The bidder understands that insulation shall be provided only in case of alloy/FlRP lining i.e. in case of borosilicate lining no insulation shall be required owing to its excellent insulation properties. Kindly confirm.

Sheet | 5 The total plan area of the openings at a particular section shall not The bidder would like to consider 20% of the plan area as the sum of of 22 be more than 15% of the plan area of concrete shell at that openings area in line with clause 7.0 of IS 4998: 2015. location. The opening size for the purpose of stress calculations shall be taken as 1.1 times the actual width of the opening. The Please confirm. extra reinforcement around opening shall satisfy the requirements given in the following documents and the highest shall be provided.

Confirmed.

Bidder to comply with stipulation of technical specification

ESP 64

65

Volume III 1.4 viii) Mechanical Works, Ch 1: SG & Auxiliaries Section 1 : Scope Volume III 3.2.1 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

37 of 47

Scale model by fabricating a three dimensional physical model of the Electrostatic Precipitator and it's ducting with a scale not less than 1:10.

Since CFD analysis shall be conducted, physical model study of ESP is not envisaged.

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The Bidder shall perform model study….

Since CFD analysis shall be conducted, physical model study of ESP is not envisaged.

The Provision as per bidding document shall prevail. The Provision as per bidding document shall prevail.

37 of 47

66

Volume III 1.4 ix) Mechanical Works, Ch 1: SG & Auxiliaries Section 1 : Scope

Opacity monitors complete with all accessories at the outlet of each pass (gas stream) of ESP but upstream of the ID Fan i.e. six (6) no’s per ESP serving one steam generator.

Opacity monitors complete with all accessories at the outlet of each Unit of ESP but upstream of the ID Fan i.e. One (1) no’s per ESP serving one steam The Provision as per bidding document shall generator shall be provided as per general practice. Kindly confirm. prevail.

Volume III 1.4 xii) Mechanical Works, Ch 1: SG & Auxiliaries Section 1 : Scope

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Complete microprocessor based ESP control system….

PLC based ESP control system shall be provided.

67

The Provision as per bidding document shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

3.1.3.1 Volume III Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

2 of 15

3.5.1 Volume III Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Volume III 3.8.2 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

5 of 15

71

Volume III 3.5.1 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

68

Bid Specification Stipulation ...ESP sizing criteria, 3.11 of this section...

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder understands that 3.11 shall be read as 3.12. Bidder understanding is correct.

The specific collecting plate area shall in no case be less than the value specified in ESP Sizing Criteria, 3.11 of this section.

Bidder understands that 3.11 shall be read as 3.12.

The hopper capacity shall be based on the inlet dust burden, gas flow rate and gas temperature indicated in ESP sizing criteria (3.11 of this section)

Bidder understands that 3.11 shall be read as 3.12.

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Minimum plate thickness shall be 18 BWG.

Minimum plate thickness shall be 18 BWG or 1.2 mm. This is as per standard practice followed by all major power utilities in India including NTPC. Bidder & its technology provider have proven global references of the same. Agreed.

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Each plate shall be shaped in one piece construction...

72

Volume III 3.5.1 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

TM The offered technology has collecting electrodes (modulok ) that are modular, assembled and lock-fitted with each other that are welded together The Provision as per by tadpoles at top and bottom. This is as per our standard offering. The same bidding document shall are installed in various plants in India. prevail.

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Necessary lubrication system shall be provided for the rapping mechanism.

Lubrication system is not envisaged for ESI rappers.

73

Volume III 3.7.3 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

8 of 15

74

Volume III 3.8.5 Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

69

70

7 of 15

Bidder understanding is correct.

Bidder understanding is correct.

Agreed.

All heaters on each level shall have same wattage and be capable of maintaining internal hoppers temperature in excess of 140 deg.C and capacity selection of these heaters shall be as per Purchaser's approval.

Bidder requests to modify the clause as: 'All heaters on each level shall have same wattage and be The Provision as per capable of maintaining internal hoppers temperature in excess of 120 deg.C bidding document shall and capacity selection of these heaters shall be as per Purchaser's approval.' prevail.

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75

76

77

78

79

80

E E1 1

Section / Part / Chapter / Volume

Clause No.

Page no.

3.9.7 Volume III Mechanical Works, Ch 1: SG & Auxiliaries Section 3 : Electrostatic Precipitator

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Volume III Mechanical Works, Ch 1 : SG & Auxiliaries Section 3 : Electrostatic Precipitator Volume III Mechanical Works, Ch 1 : SG & Auxiliaries Section 3 : Electrostatic Precipitator Volume III Mechanical Works, Ch 1 : SG & Auxiliaries Section 3 : Electrostatic Precipitator Volume III Mechanical Works, Ch 1 : SG & Auxiliaries Section 3 : Electrostatic Precipitator

Clause 3.12 point 7.0

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Clause 3.12 point 8.1

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Bid Specification Stipulation The precipitator shall be guided, anchored or supported by lubricated plates/roller bearings at such locations as may be required to limit precipitator, duct work or expansion joint forces or movement.

Bidder shall offer slide bearings (self lubricated type) having extensive global references. Same is accepted by all major power utilities including NTPC.

Inlet Dust Burden - 90 % of ash or actual predicted whichever is higher being carried forward to ESP while firing specified worst (maximum ash) coal.

The refered specification results in over design of hoppers. Bidder requests to modify clause as follows: 'Inlet Dust Burden - 85 % of ash or actual predicted whichever is higher being carried forward to ESP while firing specified worst (maximum ash) coal.' Same is as per standard industry practice. Bidder requests to modify the clause as: ESP Dust Collection loading at outlet, when all fields of each pass are in service <17 mg/Nm3 or as per MOEF requirement as on 7 days prior to bid submission date, whichever is more stringent

ESP Dust Collection loading at outlet, when all fields of each pass are in service <17 mg/Nm3 or as per MOEF requirement whichever is more stringent.

Clause 3.12 point 8.2

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ESP Dust Collection loading at outlet, when first field of each pass out of service. (mechanical collection efficiency of first field not exceeding 20% or actual, whichever is lower) <30 mg/Nm3 or as per MOEF requirement whichever is more stringent.

Clause 3.12 point 8.2

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Minimum specific collection area 260 m2/m3/ sec (at Design and Guarantee point).

Volume III Clause 3.12 Mechanical Works, Ch point 11 k) 1 : SG & Auxiliaries Section 3 : Electrostatic Precipitator

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Spacing between the collecting electrodes (Centre line to centre line) transverse to the gas flow - 300 MM

MECHANICAL BALANCE OF PLANT COAL HANDLING PLANT Volume II (Book 1 of 2.3.1-g 2)/Chapter 08

Statement of Prebid Queries & Clarification

Owner's Reply

Agreed.

The Provision as per bidding document shall prevail.

Agreed.

Bidder requests to modify the clause as: ESP Dust Collection loading at outlet, when first field of each pass out of service. (mechanical collection efficiency of first field not Agreed. exceeding 20% or actual, whichever is lower) <30 mg/Nm3 or as per MOEF requirement as on 7 days prior to bid submission date, whichever is more stringent. Bidder understands that this requirement is at collecting electrode spacing of 300 mm. In offered technology which has extensive global references, collecting electrode spacing is 400 mm for all fields. Same is accepted by all Bidder understanding is major power utilities including NTPC. Hence bidder shall offer minimum SCA correct. of 195 m2/m3/ sec (at Design and Guarantee point) with 400 mm spacing.

In offered technology which has extensive global references, collecting electrode spacing is 400 mm for all fields. Same is accepted by all major power utilities including NTPC. Agreed.

57

Demonstration of the ability of conveyor to start under full designed Whether same shall be guaranteed load 3300 TPH or any design margin to load. be considered on guaranteed load. Please clarify.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

2

Volume II (Book 1 of 2)/Chapter 08

2.3.13-c

60

Vibration is to be within allowable limits.

Please furnish allowable limit.

3

Volume II (Book 1 of 2)/Chapter 08

2.3.17-d

62

Demonstration of tippling rate of 26 wagons/hr.

There is discrepancy between two clauses. Please clarify wagon tippler tippling rate.

Volume III /Chapter 19

1.13-(3)

14

Wagon Tippler (Tandem type): Each Tippler shall operate at guaranteed capacity of 22 tips per hour.

Volume II (Book 1 of 2)/Chapter 08

2.3.17-e

62

Demonstration of side arm charger for auto operation of 60 wagon rake.

Volume III /Chapter 19

1.13-(4)

14

It shall be used for pushing/ pulling rake of maximum 58 loaded wagons of

-

-

4

5

Volume VII-TDMechanical

Detail layout drawings and data sheets

Volume III / Chapter 19 data sheet

6

Drawing No: D-0444111-235201/5202/5203...-Rev 0- Notes

-

-

Building size/dimensions/levels etc as shown above for transfer towers /others buildings are minimum required.

There is discrepancy between two clauses. Please clarify side arm charger maximum pulling capacity.

This is EPC project. functional requirement of storage capacity, rail level, rail routing, location of Wagon tippler, location of track hopper and main plant area will be maintained as per specification. Layout of CHP may be required to alter to accommodate Crusher house as proposed, keeping capacity of stock adequate for present two and future one unit. More over layout will be designed to suit to offered boiler. In such situation numbers of conveyors, crusher house, transfer house and their respective location may vary. Therefore we request to dilute the criteria of minimum dimensions in the drawings and data sheet of conveyors and allow us to design the system as required for specified performance of the plant as a whole. CHP plant will be offered to suit specified functional requirement keeping rail layout, wagon tippler, track hopper as per NIT. Bidder understands that this, being an EPC project, CHP will be designed to meet the requirement of offered boiler. Please confirm bidder's understanding. Bidder also understands that this CHP will cater to future one unit and no additional stockpile/unloading/receiving facility is going to come up.

Owner's Reply Please refer relevant standard in this regard. Each tippler shall operate at guaranteed capacity of 22 tips/hour. Caluse 1.13(3) shall prevail. Please consider 58 loaded Wagons as per Vol.III, Chapter-19. The provision as per bidding specification shall prevail. However, Bunker Building shall be designed to suit Boiler package during detailed engineering stage. It is EPC contract. Bidder is to ensure all relevent data for design & corelate.

NIT document & drawings are self explanatory. Hence The provision as per bidding specification shall prevail.

Please confirm bidder's understanding. 7

Volume III /Chapter 19

1.14-vii

16

All safety guards wherever needed shall be provided for safety of operators.

Whether belt safety guard is required for carrying & return side. Please clarify. This shall be decided during detail engg stage. Yes as per specification.

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Section / Part / Chapter / Volume

Clause No.

Page no.

8

Volume III /Chapter 19

1.15-vi

18

Angle of surcharge: 25 degree

whether same angle shall be considered in belt width calculation. Please clarify.

9

Volume III /Chapter 19

1.19-j

29

Sizing calculation of ring granulator, rotary discharge machine, vibrating screen feeder and vibrating feeder.

Same shall be submitted subject to availability from respective vendor.

Calculation in support of strength of magnet of ILMS / SEM.

Same shall be submitted subject to availability from respective vendor.

10

Volume III /Chapter 19

1.19

29

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply The provision as per bidding specification shall prevail.

This shall be decided during detailed engineering.

This shall be decided during detailed engineering. 11

Volume III /Chapter 19

3.0-vii

32

Clearance between top of rail track / road and bottom of conveyor gallery shall be kept at least (6) meter for conveyor gallery crossing over rail track/ road.

There is discrepancy between two clauses. Whereas in tender drawings of conveyor profile same is 13.8 mtr for BC-5A/5B. whether gallery can be lowered. Please clarify.

Volume VI/Chapter 6 12

Volume III /Chapter 19

6.05.00

2

Main roads / Railway crossings & crane access 8000 mm

H-ii

38

Rating of all drive motor of conve yor shall not be less than 120% of the power required at drive motor output shaft at specified guaranteed capacity.

3.0-vi

32

This shall be decided during detail engg stage.

There is discrepancy between two clauses. Please clarify motor margin. Clause No.3.0-vi, Page-32 of bidding specification shall prevail.

The drive motor of each belt conveyor shall be rated for minimum 115% of actual requirement of driven equipment at motor output shaft at the specified guaranteed capacity of conveyor.

13

Volume III /Chapter 19

H-vi-c

39

Service factor shall not be less than 1.5 (to be used on belt kW) for Whether Belt KW means consumed power at pulley shaft. Please clarify. coupling selection.

14

Volume III /Chapter 19

Data Sheet: Belt Conveyors

43

Motor speed, RPM (Syn.) for BC-1A/1B, BC-7A/7B, BC-8A/8B & RBC-1A/1B are 750 rpm.

This is beyond prevailing practice in CHP. Please clarify the basic requirement and basis of selection of rpm of motor to be offered for conveyors.

15

Volume III /Chapter 19

Data Sheet: Belt Conveyors

43

Dual drive / Belt type and cover thickness

It is being EPC project we have noted the selection of dual drive in the specification. We request to allow us to design the system as per requirement as optimum solution. Please confirm.

Belt kW means consumed power at drive pulley shaft. The provision as per bidding documents shall prevail. Such issues may please be discussed during detailed engg stage.

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Section / Part / Chapter / Volume

16

Volume III /Chapter 19

17

18

Volume III /Chapter 19

Volume III /Chapter 19

Volume III /Chapter 19

Clause No.

Page no.

Schedule of hoist

59

C 'WT of Conv.: EH hoist for all conveyors

F-ix

37

A lifting beam with Manual Hoist o f minimum capacity 150% the total weight of counter wt unit shall be provided, located on the centre line of the take-up unit and above the Take-up Pulley in case of VGTU and above the Cwt. Box in case of HGTU.

M-14-1.1

80

Indexer if required shall be supplied to work in conjunction with side arm charger to achieve the desired tipping capacity of tippler.

1.13-(3)

14

M-13 (5.2)

73

M-18, a)

Bid Specification Stipulation

Statement of Prebid Queries & Clarification 150% load consideration if way beyond normal engineering practice in CHP. There is also a discrepancy of type of hoist between two clauses. Please clarify hoist type above counter weight in VGTU & HGTU. We also propose 125% of counter weight as hoisting capacity. Please confirm.

Clause . No.[F]/Belt Takeups/(ix) of bidding specification shall prevail.

Please clarify the requirement of indexer for achieving 44 tips per hour in each tandem tippler. Bidder shall ensure that each tandem tippler operates at guaranteed capacity of 22 tips/hr or 44 wagons unloaded per hour.

Each Tippler shall operate at guaranteed capacity of 22 tips per hour. It shall be capable of safely unloading Forty four (44) numbers of Wagons per hour on a continuous basis Including hauling, pause, decoupling and weighing time etc. in conjunction with side arm charger. It shall also perform function of weighing the gross & tare weight of wagons by incorporating an integral weighbridge.

Owner's Reply

Owner to note that requirement of integral weigh bridge and Dozer/Hydra/Payloader is not compatible.

The above is feasible had it been rota side wagon tippler in which wagon tippler table is fixed type and not floating type. Necessary ramp/access shall be provided so that Payloader/ 94 of 154 Hydra/ dozer can access hopper top for removal of oversize lumps Since, this is rotary type wagon tippler, it is impossible to fulfil the functional of shale, sandstone which come along with ROM coal. requirement of dozer with integral weigh bridge in all scenario as in this case wagon tippler table is floating type and integral weigh bridge structure will cause hindrance to the access/movement of Dozer. Also, there is no reference where integral weigh bridge is provided for rotary type wagon tippler.

Suitable weigh bridges to suit the tippler requirement may please be provided to meet requirement of bidding specification.

In view of above, bidder suggest to provide in motion weigh bridge (inhaul & out haul) instead of integral weigh bridge to fulfil the functional requirement of Bobcat machine. Owner is requested review and issue suitable amendment. 19

Volume III /Chapter 19

M-18, a)

Due to non clarity, Owner is requested to clearly specify the arrangement for 94 of 154 Necessary ramp/access shall be provided so that Payloader/ Hydra/ dozer can access hopper top for removal of oversize lumps dozer access to hopper. of shale, sandstone which come along with ROM coal. Also, please clarify whether covered or open ramp is to be considered.

This shall be decided during detail engg stage.

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Section / Part / Chapter / Volume

Clause No.

Page no.

20

Volume III /Chapter 19

M-18 (1.2)j

73

21

Volume III /Chapter 19

1.10-(13)

11

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

The track hopper outlet/shelf shall be provided with sealing plates Please clarify the requirement sealing plate. for adjusting coal height over RDM shelve so that no coal falls into conveyors or floor when RDM is not operating.

Sampling tower

Separate sampling tower may be a costly proposition. Bidder proposes that CSU shall be installed in respective transfer tower or crusher house. Please confirm.

22

Volume III /Chapter 19

1.14-(vi)

16

Mono rail beam with Electric Hoist shall be fixed above floating T.U. Pulley centreline of all vertical gravity take-up arrangements for belt conveyors so as to lift the takeup pulley / counterweight at the time of belt joining to get the required loop.

Bidder proposes that combination of electric hoist, manual hoist & chain pulley block shall be considered at VGTU. These hoist shall be common for entire plant. Please confirm acceptance.

23

Volume III /Chapter 19

1.14-(x)

16

Adequate maintenance space (minimum 1500mm clear) around equipment

Owner to note that 1500mm space is way beyond normal practice, hence bidder proposes that maintenance space of 1000 mm clear around equipment is adequate for standard CHP. Please confirm acceptance.

Owner's Reply This shall be decided during detail engg stage. The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

24

Volume III /Chapter 19

1.18- (6)

27

One operator’s cabin in each location mentioned below: a) Crusher House b) On Tripper Floor in Bunker Row# 1/2 (Unit-1) c) On Tripper Floor in Bunker Row# 1/2 (Unit-2)

Owner to note that separate operator's cabin at crusher house & bunker floor are additional requirement beyond normal practice in CHP and not required The provision as per functionally. Hence, bidder request Owner to delete this requirement. bidding specification shall prevail.

25

Volume III /Chapter 19

3.0-(iii)

32

Wrap angle shall be generally 200 °/400° for single snub drive pulley/ dual drive pulley respectively.

Bidder proposes 210 deg wrap angle for single snub drive pulley as per standard CHP.

confirmed .

Please confirm acceptance. 26

Volume III /Chapter 19

3.0-(iv)

32

An extra allowance of minimum 15% shall be kept on the CHP will be designed as per codes and standards. This is an additional calculated radius of curvature. Further suitable holding down pulley requirement beyond that. Therefore bidder proposes not to consider extra shall be provided at concave curve of all conveyors. allowance over calculated radius. Please confirm acceptance.

This shall be decided during detailed engg stage. We may agree with bidder comment.

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Section / Part / Chapter / Volume

Clause No.

Page no.

27

Volume III /Chapter 19

3.0-(v)

32

Bid Specification Stipulation All inclined Conveyors shall be provided with external holdback device.

Statement of Prebid Queries & Clarification Gear Box with integral hold back shall be sufficient for this application.Hence, bidder does not envisage external holdback device for all inclined conveyor. Please confirm acceptance.

28

Volume III /Chapter 19

3.0-(v)

32

Further conveyor shall come to halt as early as possible.

Owner's Reply

The provision as per bidding specification shall prevail.

Based on coasting time calculation, Stopping time will be decided. confirmed. Please confirm acceptance.

29

Volume III /Chapter 19

3.0-(vi)

32

Ai value shall be considered 2.94 lb (minimum)

This is extra codal requirement and beyond recommendation of CEMA. Hence, maximum Ai value 2.8 lb shall be considered in conveyor power calculation. Please confirm acceptance.

30

Volume III /Chapter 19

H-vi)b)3

39

160 kW & above - Actuator operated Scoop type fluid coupling (air- Upto 160 KW being LT motor, bidder proposes to offer delayed filled fluid cooled design) coupling upto 160 KW. Please confirm acceptance.

31

Volume III /Chapter 19

3.0-(vi)

32

Minimum value of Ky to be considered shall not be less than 0.021 This is extra codal requirement and beyond recommendation of CEMA. Ky in the above calculations. value shall be selected as per CEMA-5 recommendation. Please confirm acceptance.

32

Volume III /Chapter 19

4.0-B-(iii)

33

Normal Spacing of idler shall be 1.0m for carrying side and 3m on return side.

33

Volume III /Chapter 19

4.0-C-(i)

34

Pulleys shall be of welded steel construction (Mild Steel This is against standard design practice. As per standard CHP application conforming to IS: 2062, tested quality) having continuous rim and internal stiffeners are not used in conveyors pulley. two end discs fitted with hubs and the required internal stiffeners. Please confirm acceptance.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

To reduce the conveyor power, bidder proposes spacing for carrying idler 1.1 The provision as per m & for return idler 3.3 m. bidding specification shall prevail. Please confirm acceptance.

This shall be decided during detail engg stage.

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Section / Part / Chapter / Volume

Clause No.

Page no.

34

Volume III /Chapter 19

4.0-C-(iii)

35

Bid Specification Stipulation pulley. Shaft diameter shall be calculated based on rubber lagging only. i.e. T1/ T2 etc. shall be based on rubber lagging only.

Statement of Prebid Queries & Clarification

Owner's Reply

Friction between pulley and belt decides counter weight to avoid slip. Once counter weight is decided this issue does not have any effect on belt tension. Therefore considering a hypothetical tension to arrive at shaft diameter is conceptually not desirable. This will make the system grossly over designed The provision as per bidding specification shall beyond any functional requirement. We propose to consider actual lagging prevail. for all calculations. Please confirm acceptance.

35

Volume III /Chapter 19

4.0-C-(x)

36

Stringer size: ISMC-200 (Minimum); Short support: ISMC-125 (Minimum); Short support spacing: 3m (Maximum) Non loading area and 2.4m (Maximum) in impact loading zone.

Member size shall be finalized based on design requirement. However, minimum size will be ISMC 150 for stringer, ISMC 125 for short post. In addition to that bidder proposes maximum short post spacing 3.3 m. Please confirm acceptance.

36

Volume III /Chapter 19

4.0-D-i

36

Minimum height of skirt plate shall be 1000 mm.

The height of skirt plate shall be decided based on DFDS requirement. Please confirm acceptance.

37

Volume III /Chapter 19

4.0-D-i

36

Minimum skirt board shall be as shown on drawings.

Maximum skirt length will be 4.5 meter after front edge of last feeding chute toward belt travel direction. Please confirm acceptance.

38

Volume III /Chapter 19

4.0-D-ii

36

Back plate of skirt board shall be kept about 1200mm away from the feed Chute rear edge.

Back plate of skirt board shall be kept about 500 mm. Please confirm acceptance.

39

Volume III /Chapter 19

4.0-F-i

36

Screw take-up (if applicable) shall be hydraulic operated type.

Screw take-up shall be manually adjustable type. Please confirm acceptance.

40

Volume III /Chapter 19

4.0-F-iv

37

Stair (800mm wide) with handrails shall be provided for VGTU.

Ladder shall be provided instead of stair in VGTU tower. Please confirm acceptance.

41

Volume III /Chapter 19

1.15-xx-f

20

Stringer & short support size shall be as per provision of bidding specification shall prevail. Short post, spacing may be kept to suit.

RCC staircase [1500mm wide] shall be provided for approach to This requirement is additional wrt to standard CHP and functionally not Tail/ portion of Conveyor/ other equipment etc. which are located in required. Therefore bidder requests to delete this requirment. pit/ underground portion of Wagon tippler Complex/ Track Hopper Complex/ Junction Towers Please confirm acceptance.

confirmed.

The provision as per bidding specification shall prevail. Back plate shall be kept to suit Dust Suppression System requirement. The provision as per biiding specification shall prevail & duct manually screw type. The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

42

Volume III /Chapter 19

M-19-(2.8)

98

Bid Specification Stipulation Pan Speed: Up to 0.25 m/sec

Statement of Prebid Queries & Clarification Bidder proposes maximum pan speed up to 0.36 m/s as per equipment manufacturers' design requirement. Please confirm acceptance.

43

Drawing No: D-0444111-23-5201-Rev 0

-

-

44

Volume III /Chapter 19

Data Sheet: Belt Conveyors

45

Volume III /Chapter 19

M-21-(2.5)

Owner's Reply

Rail level

Please furnish rail level at WTC & track hopper area.

43

Belt Width: 2000 mm

Belt width 1800 mm is adequate for this project.

105

Feed material/ size: ROM Coal (Refer Cl. No. Design Criteria)

Please furnish sieve analysis of coal for optimum screen sizing.

Please confirm acceptance.

This shall be decided during detail engg stage.

This will be furnished during detailed engg stage. The provision as per bidding specification shall prevail. Refer Cl.# 1.5 (Design Criteria & Gen. Requirement for CHP) & Bidder's past experience in this regard.

46

Drawing No: D-0444111-23-5200-Rev 0

-

-

CHP Layout

Please furnish AutoCAD drawing of same. This will be furnished during detailed engg stage. Plot Plan autocad drawing enclosed. (reffer addendum for plot plan)

47

Drawing No: D-0444111-23-5200-Rev 0

-

-

Co ordinates of Wagon tippler complex, track hopper & crusher house.

Drawing No: 111-290200-Rev 0 48

Volume VI/Chapter 2

Drawing No: D-0444111-23-5200-Rev 0

There is discrepancy between two drawings, co-ordinates of wagon tippler complex, track hopper & crusher house are not matching. Please clarify.

2.8.1

-

8

Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level.

In layout plan for Coal Handling Plant different FGL has been considered in bulb area, e.g in WTC & TH: RL61.0 & stockyard, crusher house: RL60.0.Main plant area is at RL 64.5.

RL level in CHP area.

Please clarify the RL of entire coal handling plant along with rail level.

Any minor descrepancy shall be adjusted during detailed engg stage.

The provision as per bidding specification shall prevail.

-

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 49

Section / Part / Chapter / Volume Drawing No: D-0444111-13-5300-Rev 0

Clause No.

Page no.

-

-

Drawing No: D-0444111-12-3605-Rev 0 50

Volume III /Chapter 19

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Typical Gallery section: Side Walkway 1000 mm & center walkway There is discrepancy in referred clauses. Please clarify the same. 1200 mm

Typical LHS cable Gallery section: Side Walkway 1100 mm & center walkway 1400 mm 1.15-iv

18

14.2

5

Volume VI/Chapter 14

Bulk Density of Coal: 1050 kg/m3 (for load / stress on structure)

Thus coal load per unit length of each moving conveyor shall be: Rated Capacity of Conveyor system 1100 1.6 X ------------------------------------------ X ----Conveyor Belt Speed 800

As far as design of Mechanical Equipment, Technological Structure are conceved. Please follow Cl.No.1.15/Design Criteria & General Requirement of CHP.

Unit weight of coal shall be taken as 1200 Kgs. / cum. for design purposes

Ch 1: SG & Auxiliaries Section 2 : Design Basis of SG & Auxiliaries and SCR 51

52

15 For all capacity (volume) calculation and structural design (load calculation) unit weight of coal shall be 800 kg/m3 and 1200 kg/m3 respectively.

iii), (e)

33 of 120

Drawing No: D-0444111-235203/5204/5205/5206/ 5207/5208/5209/5210Rev 0

-

-

Volume III /Chapter 19

1.15

Distance between center line of two conveyors

Bidder proposes that distance between center line of two conveyors shall be finalized as per layout requirement. Please confirm acceptance.

19

For underground portion of above buildings, floors & access stairs (1500mm wide) shall be of RCC

53

Volume III /Chapter 19

Minimum width of stairs shall be 1200mm generally. 6.07.03

3

M-22

106

Up to 15% [normal] & up to 20% during rainy season

1.15

18

Moisture Content: Up to 15%

The provision as per bidding specification shall prevail.

There are discrepancies in referred clauses. Please clarify the moisture content to be considered.

Volume III /Chapter 19

The provision as per bidding specification shall prevail.

There are discrepancies in referred clauses. Please clarify access stair width.

Volume VI/Chapter 6

Please follow drawing for Conveyor Gallery Section Drg No. D-0444-111-135300.

There are discrepancies in the clauses. Please clarify coal density to be considered for load/structural design.

Volume VI/Chapter 14

14.17

Owner's Reply

Bidder shall consider upto 20% moisture during rainy season.

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Section / Part / Chapter / Volume

Clause No.

54

Volume III /Chapter 19

1.19

Page no.

Bid Specification Stipulation

28 & 29 Design Calculation / Technical Documents: Load data Calculation etc. Electric load list / Hoist Schedule (manual & electric)

Statement of Prebid Queries & Clarification Load data calculation & electrical load list for hoist shall not be submitted. However, load data in building GA drawing & hoist schedule shall be submitted. Please confirm acceptance.

55

Volume III /Chapter 19

1.19

28 & 29 Conveyor profile drawing / flow diagram / other drawings etc.

Conveyor profile is integral part of GA drawings of conveyors. Separate drawing will not be submitted. Please confirm.

56

57

58

Volume III /Chapter 19

Volume III /Chapter 19

Volume III /Chapter 19

C) I

35

The end disc of drive pulley, discharge pulley, take-up pulley and The referred clauses are contradictory. tripper discharge pulley and any other H.T. pulley shall be turbo web design for uniform stress distribution. The material of end disc Please specify the requirement. shall be cast steel.

Conveyor data sheet Sl no 14.9

44

Forged steel

M-18) 1.2

94

A well-ventilated & lit “Tools & Spares Storage Room” above ground shall be provided combined with Compressor House Building# ACH-1 near the Track Hopper Complex for keeping spares of rotary discharge machine and belt conveyors etc.

1.5, ii.

3 of 154 Coal Handling Plant shall be operated and maintained by the Contractor for a period of three (3) months from date of handing over of the entire CHP package to M/s STPL.

Owner's Reply (i) Bidder shall confirm that Electric Load List shall be furnished during detailed engg stage and also (ii) civil load data with relevant calculations where necessary shall be furnished during detailed engg stage. This shall be decided during detail engg stage.

This will be decided during detailed engg Stage.

Please specify the space requirement. This will be decided during detailed engg Stage. Bidder understands that CHP shall be operated and maintained by the Owner under the supervision of contractor for a period of three (3) months from date of handing over of the entire CHP package to M/s STPL.. Please confirm.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

59

Volume III /Chapter 19

1.7,11

E2 60

61

62

Volume III /Chapter 19

1.4

Volume III /Chapter 19

2.8

ASH HANDLING PLANT Vol-III/Ch:21 Ash Handling System

21.2.3

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

4 of 154 Travelling Tripper# TRT-1A/1B/ 2A/2B with three way discharge chute having flap gates.

Discrapancy observed in referred clauses for traveling tripper discharge chute.

One (1) linear actuator operated flap gate shall be provided to direct the material flow through the tripper’s two (2) way discharge 71 of 154 chute to deliver coal either into Coal Bunker Slot opening or the tripper conveyor itself.

Owner is requested to clarify the same.

3 of 52 Fluidizing blowers shall be provided for each unit for easy dislodging of ash from all the fly ash hoppers -

Bidder envisage fluidizing of ESP fly ash only. However, fluidising is not envisaged for APH hopper ash as it is coarse in nature. Owner is requested to confirm bidder's understanding.

-

Vol-III/Ch:21 Ash Handling System

21.2.3

3 of 52 For each storage silo, provision shall be made for unloading dry fly There is a ambiguity of no. of unloaders to be provided below each FA silo. ash directly to trucks from each silo. Each storage silo will be As per Fly ash silo area flow diagram, total 8 nos. unloading points are provided with … shown whereas as per specification referred clauses total six (6) nos. unloading points shall be provided.

Vol-III/Ch:21 Ash Handling System

21.31

46 of 52 FLY ASH SILO Technical Datasheet: No of outlets : 6

Dwg No: 111-13-5203

-

Vol-III/Ch:21 Ash Handling System

21.2.4.2

-

Flow diagram for fly ash handling system: Fluidizing air and pad are shown in APH hoppers

Owner is requested to check and amend.

Confirmed.

Six (6) unloading points shall be considered.

Flow diagram for fly ash silo area: total 8 nos. unloading points are shown

4 of 52 1st stage slurry pumps shall have scoop controlled Fluid Couplings There is a ambiguity for ash slurry disposal pump speed variation in tender to vary the duty point within (+) 20% to (-) 40% of design duty point. specification as referred herewith. Request Owner to revisit and issue amendment.

21.10.1

Last Bunker shall be fed by head pulley. Hence three way chute required for each tripper.

Type of discharge chute: 72 of 154 Three-way with required flap gates having Linear actuator

Dwg No: 111-13-5205

Vol-III/Ch:21 Ash Handling System

Owner's Reply

Data Sheet of Horizontal Centrifugal Pumps: 33 of 52 Speed variation (+)10% to (-)45% with respect to rated design point in case of ash disposal pumps

(+)20% to (-)40% shall be considered. As per the clause 21.2.4.2 of volume III chapter 21.

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Section / Part / Chapter / Volume Vol-III/Ch:21 Ash Handling System

Clause No. 21.2.4.3

Page no.

Bid Specification Stipulation

4 of 52 The slurry pumps shall be capable of delivering slurry to a 20 M dyke height (considering future raising of Dyke height) from existing grade level.

Statement of Prebid Queries & Clarification

Owner's Reply

There is an ambiguity in ash pond ultimate dyke height as referred tender clauses beside, Hence, bidder has considered 12 M dyke height (considering future raising of Dyke height) from existing average grade level of ash pond area for ash 18 M dyke height shall be slurry pump head selection. considered.

64

Vol-VI/Ch:16 Ash Pond

16

1 of 2

111-29-02000

-

-

The ultimate dyke height shall be 12m.

Please confirm bidder's understanding.

Plot Plan: AHP facilities (33,34,35,37,38,39,40 etc)

i) Bidder understand that location of all AHP facilities as shown in the plot plan is tentative. EPC bidder can relocate the AHP facilities as per overall plant layout and same shall be provided for owner's approval during detail engineering.

Confirmed.

Request owner to confirm bidder's understanding. 65

vol-III/Ch 33: Plant Layout Requirement

33.4, 41)

111-29-02000 21.8.2.3 Vol-III/Ch:21 Ash Handling System

12 of 15 41) Ash slurry pipe lines shall be routed on pedestals except at In absence of clarity, request owner to mark the pipe rack in plot plan upto road/rail crossings where pipe culverts shall be provided. Minimum which the ash slurry disposal pipes to be routed on to pipe rack and also height of pedestal shall be 1000 mm from FGL. mark the corridor on which ash slurry pipes shall be routed on the pipe pedestals for disposal upto ash pond. Plot Plan: AHP slurry pipe corridor 29 of 52 Normally slurry pipes shall be on pipe rack in plant boundary & on pipe pedestal outside plant boundary.

Marked on the revised Plot Plan.

There shall be four (4) cross country slurry disposal pipes for two units routed on pipe rack pedestals 66

Vol-III/Ch:21 Ash Handling System 111-29-02000

-

-

Plot plan

As per plot plan, owner has shown rail below main FA silos (4 nos.). However, AHP tender specification (Vol-III, Ch: 21) and AHP flow diagram do not cover any requirement related to rail unloading through Main FA silos. If rail unloading is envisaged, request owner to please check and confirm following concerns related to rail unloading. i. The type of wagon (open/close) to be considered for rail unloading. Ii. In which form ash to be unloaded to wagon. Iii. What minimum clear height to be considered below FA silo iv In Haul and Out Haul rail track requirement for rail unloading.

Rail unloading envisaged. All necessary guidelines required shall be followed by bidder.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

67

Vol-III/Ch:21 Ash Handling System

-

-

AHP technical specification mention (vacuum + Pressure) type fly ash pneumatic conveying system for fly ash conveying from ESP to Main Fly ash silo.

Please allow bidder to adopt two stage pressure (Pressure+Pressure) type fly ash pneumatic conveying system in lieu of vacuum+Pressure type FA The provision as per conveying system for fly ash conveying from ESP to Main Fly ash silo bidding specification shall considering the higher route length of fly ash conveying (ESP to silo). prevail.

68

111-29-02000

-

-

Plot Plan: Location of Main FA silos

As per the location of the FA silo, Second stage fly ash pressure conveying distance shall be approximately 1800 Meter and each FA pressure conveying line capacity specified is 120 TPH. Also, while laying the FA pressure conveying path, lot of bends will also be encountered as per plot plan. In The provision as per such scenarios, consequences of FA line chockages shall be higher. bidding specification shall prevail. In view of this, to achieve better system performance, request owner to allow bidder to relocate Main FA silos nearer to the plant as much as possible.

69

111-29-02000

-

-

Vol-III/Ch:21 Ash Handling System Vol-III/Ch:21 Ash Handling System

21.2.5.1 21.2.4.3

Plot Plan: As per the ash slurry pipe corridor shown in the plot plan, ash 4 of 52 slurry pipe length upto ash pond would approximately 2600 to 2650 meter 4 of 52 Ash disposal area is tentatively 4.0 KM away from slurry sump. Length of each slurry pipe line shall be considered as 6 KM including garlanding on ash dyke.

70

71

Vol-III/Ch:21 Ash Handling System

21.2.5.4

Vol-III/Ch:21 Ash Handling System

21.2.6

4 of 52 The system shall have provision of chemical dosing system as The referred clause is applicable for AHP clarification system only. necessary for coagulation and efficient settlement of ash carryover as well as chemical treatment. Please confirm bidder's understanding. 5 of 52 The overflow from BA hopper shall accumulate in BA hopper overflow sump having a buffer storage capacity of 20 minutes. Basis for selection of capacities of various tanks/ sumps: Bottom ash overflow sump : 10 Min

Vol-III/Ch:21 Ash Handling System

21.3.1, h)

There is a ambiguity in referred clauses beside. In view of this, owner is requested to check and confirm the following concerns. 1) Each pipe length 6 KM. 1) Ash slurry pipe total supply quantities 2) Ash slurry pipe length to be considered for ash slurry pump head selection. 2) For pump head calculations length of pipe 6 KM. (Bidder has to optimize and acess as being an EPC Project.)

Confirmed.

There is a ambiguity for BA overflow sump capacity as referred clauses beside. i.e. 20 min vs 10 min. Request owner to revisit and confirm the BA overflow sump/tank effective storage capacity.

20 minutes shall be considered.

7 of 52

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Section / Part / Chapter / Volume

Clause No.

Vol-III/Ch:21 Ash Handling System

21.37

111-13-5201

'-

Page no.

Bid Specification Stipulation Technical Datasheet of BOTTOM ASH OVERFLOW TANK: Shall be of self supporting type or underground sump.

'-

BA Handling System flow diagram: Horizontal type BA overflow pump shown with above ground tank MOC : MS Construction

Statement of Prebid Queries & Clarification There is ambiguity for BA overflow sump (whether above ground or underground) as per referred tender clauses besides. Request owner to relook and confirm the location of BA overflow sump/tank and sump.

BA overflow sump - Above ground with horizontal centrifugal pumps.

MOC of BA overflow sump: RCC overflow transfer sump Vol-III/Ch:21 Ash Handling System Vol-III/Ch:21 Ash Handling System 73

Vol-III/Ch:21 Ash Handling System

21.6.8 21.10.1 21.16

Owner's Reply

26 of 52 Data Sheet of Horizontal Centrifugal Pumps BA overflow water pumps : Horizontal type 32 of 52 39 of 52 DATA SHEET - BOTTOM ASH HOPPER: Temp. of Bottom Ash: 1050 Deg.C

Owner has specified the temperature of bottom ash as 1050 Deg C. The bottom ash temperature is specified by boiler OEM as per their site proven experience. Hence, bidder envisage to consider bottom ash temperature as per boiler OEM recommendation for BA overflow cooling water pump capacity selection. However, MOC of BA hopper refractory shall Confirmed. be selected considering 1050 Deg C temperature as specified in tender specification. Request owner to confirm bidder's understanding.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 74

Section / Part / Chapter / Volume

Clause No.

Vol-III/Ch:21 Ash Handling System

21.2.7.1, 21.2.7.2

Vol-III/Ch:21 Ash Handling System

Vol-III/Ch:21 Ash Handling System

75

21.3.5.1

21.3.5.2

Page no.

Bid Specification Stipulation

5 of 52 Ash Laden Water Clarification System: Water from the BA Overflow Pump discharge of both units, recovery from ash disposal area and any other drains shall be routed to the clarification plant. Functionally, this plant (which is common to both the units) The ash water collecting tank along with surge tank, clarifier and 10 of 52 recovery water tank shall be provided. The system shall be sized for 75% ash water recovery. Ash Water Recovery System: -One no. ash water settling tank and surge tank. 10 of 52 -One (1) clarifier sized for 75% ash water recovery with sludge sump having 2 x 100% vertical sludge disposal pumps. -Recycled water Storage over ground tank along with pump house. The pump house shall be equipped with crane, adequate maintenance space, MCC & switchgear room

111-13-5202

'-

'-

As per Flow diagram of ash water and ash slurry system, BA overflow water shall be transferred to settling tank, surge tank and then clarifier system

111-13-5206

-

-

Clarifloculator system AHP flow diagram: borewell pump (near ash pond) discharge line to AHP clarifier is shown.

Statement of Prebid Queries & Clarification

Owner's Reply

There is a contradiction for following AHP facilities as per referred tender clauses and AHP flow diagrams. i) Whether common AHP clarifier is proposed for ash pond recovery and BA overflow water from both the units and AHP drains etc. or two separate AHP clarifier. Ii) Please clarify the requirement of settling tank and surge tank (referred in tender specification clauses and AHP flow diagram) as there shall be stilling pond in ash pond area as specified in cl. no. 16.0 of civil specification (VolVI/Ch:16 Ash Pond). Stilling pond will fulfil the function of ash settlement prior to transferred into ash pond recovery sump.

i) Common AHP clarifier for ash pond recovery, BA overflow water of both units and other drains of Ash Handling System. Settling Tank & Surge Tank not required.

As per clarifloculator system AHP flow diagram, Borewell pump (near ash pond) discharge line to AHP clarifier is not applicable for AHP clarifier area. Please amend the flow diagram.

The Provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

76

Vol-VI/Ch:16 Ash Pond

16

1 of 2

ASH POND: For developing storage capacity, one storage lagoon for Fly Ash disposal of 9 years (as per MOEF notification) by High Concentration Slurry Disposal (HCSD) system with sedimentation basin and one storage lagoon for disposal of 9 years (as per latest MOEF notification) bottom ash by wet slurry disposal system with one overflow lagoon for storing decanted water from above storage lagoons will be constructed.

Statement of Prebid Queries & Clarification i) There is a ambiguity for type of Ash pond/storage lagoon. Request owner to review and confirm the type of ash pond required. As per mechanical AHP tender spec, Fly ash wet disposal is through lean slurry mode. HCSD system is not envisaged. Hence, HCSD lagoon, sedimentation pond are not applicable for this project.

Owner's Reply (i) HCSD System not envisaged. Only ash slurry disposal through lean slurry mode shall be considered.

ii) If both BA and FA slurry shall be disposed into ash pond in lean slurry (ii) Only 1 lagoon is mode, please confirm whether only one lagoon is required or two lagoons are required. required for proposed (2X660 MW) units.

77

Vol-III/Ch:21 Ash Handling System

'-

'-

Vol-VI/Ch:16 Ash Pond

16

1 of 2

As per Mechanical section AHP tender technical requirement and AHP flow diagram, HCSD system is not applicable. Fly ash shall be conveyed in lean slurry mode only.

Further, to start with only about 30 acres of land in one of the bottom ash lagoon will be provided with impervious liner and balance part of the bottom ash lagoon shall be lined by spreading high concentrated fly ash during initial stage of slurry disposal.

iii) Please specify total ash pond area available for proposed unit (2X660 MW) (iii) Refer Plot Plan (307 iv) If HCSD is not applicable, request owner to issue amendment of "chapter - acres) 16 ash pond" (iv) HCSD not applicable. No separate amendment will be issued. Bidder understand that if HCSD system is not applicable for this project, ash pond area (307 Acre) as specified in plot plan shall be used for proposed Units (2X660 MW) only. Please confirm bidder's understanding.

78

111-29-02000

-

-

Vol-VI/Ch:16 Ash Pond

16

1 of 2

Plot Plan: ash pond area (307 Acre) As per MOEF notification, 100 percent fly ash utilization is to be achieved progressively within 4 years starting with 50% in 1st year and 70% & 90% in 2nd & 3rd year respectively of plant commissioning. Considering utilization of fly ash as 30%, 50%, 80% & 90% in 1st, 2nd, 3rd & 4th year respectively of plant commissioning.

Vol-VI/Ch:16 Ash Pond

16

Confirmed.

1 of 2

In absence of input, request owner to please furnish following design basis for ash pond storage volume calculation:i) Plant operating condition (whether 100% TMCR or BMCR) ii) Type of coal (whether worst coal or design coal) iii) Placed density of ash to be considered for ash pond storage sizing iv) Ash distribution for each year (Bottom ash and Fly ash) considering the fly ash utilization philosophy

Ash dyke shall be developed for 4 years of ash generation (BA+CA+FA) while firing worst coal. Placed density 1.4 T/M3.

The starter dykes around the storage pond shall have total storage

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 79

Section / Part / Chapter / Volume Vol-III/Ch:21 Ash Handling System

Clause No. 21.2.7

Page no. 5 of 52 AHP clarifier

Bid Specification Stipulation

Statement of Prebid Queries & Clarification Pleas provide the following inputs as the same is missing in the specification. i) AHP clarifier Technical Datasheet ii) Guaranteed outlet particle size in AHP clarifier outlet clarified water.

Owner's Reply

Collection sump having a capacity of 200 M3 shall be provided. From this sump the water shall be pumped the clariflocculator. The specification of the clariflocculator, chemical dosing system, chemical house sludge handling system etc shall be as per Chapter-5. Clariflocculator shall be designed for an inlet TSS of 1000 ppm with a guaranteed output of 20 ppm TSS. The clarified water shall be routed to ash water sump.

The capacity of clariflocculator shall be as per the ash slurry water balance considering 75% ash water recovery from ash pond. 80

111-13-5205

-

Vol-III/Ch:21 Ash Handling System

21.2.10, c)

In absence of clarity, bidder understand that all the drains from BA hopper FA handling system flow diagram: vacuum pump area sump pump discharge is shown as terminating area, vacuum pumps area and Bottom ash hopper overflow water shall be into ash slurry sump/clarifier transported to the AHP clarifier only as per 21.2.10. Owner is requested to confirm bidder's understanding. Drains from BA hopper area, vacuum pumps area and Bottom ash 6 of 52 hopper overflow water shall be transported to the AHP clarifier. -

Confirmed.

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Section / Part / Chapter / Volume

Clause No.

Page no.

81

111-13-5205

-

-

Vol-III/Ch:21 Ash Handling System

21.3.4, a)

Vol-III/Ch:21 Ash Handling System

21.3.1, h)

82

Vol-III/Ch:21 Ash Handling System 83

84

85

86

87

21.3.5.2

Bid Specification Stipulation FA handling system flow diagram: vacuum pump area sump pump is located in vacuum pump house

Request owner to please confirm bidder's understanding.

7 of 52 Equipment Sizing Criteria: Recovery water to be designed for 70% of total water outflow with slurry

In absence of clarity, bidder understand that capacity of recovery water pumps and associated downstream system (piping, clarifier etc.) shall be sized considering 70% of total ash water is being recovered from disposal area.

10 of 52 One (1) clarifier sized for 75% ash water recovery

21.3.1, d)

8 of 52 Each Fly ash Storage Silo (RCC construction) shall have a capacity to store 1800 T dry fly ash (dry ash basis).

Vol-III/Ch:21 Ash Handling System

21.8.1, m)

28 of 52 Four (4) RCC fly ash silos (each 1800 T capacity)

Vol-III/Ch:21 Ash Handling System Vol-III/Ch:21 Ash Handling System

21.31

8 of 52 Angle of repose in the fly ash silo shall be considered as 45 Deg.

Datasheet of FLY ASH SILO: 47 of 52 Free Board: 700 mm

21.31, 1.4.12

Vol-III/Ch:21 Ash Handling System

21.31, 1.2

Vol-III/Ch:21 Ash Handling System

21.31, 1.4.12

47 of 52 Datasheet of FLY ASH SILO: Free Board: 700 mm

Vol-III/Ch:21 Ash Handling System

21.31, 1.4.9

47 of 52 Particulate Emission at Vent filter Outlet: Below 30 ppm

21.3.4, e)

Confirmed.

75% shall be considered as per clause 21.3.5.2 chapter 21, Vol.III.

In absence of clarity, bidder request owner to please clarify and confirm the effective storage capacity of each fly ash silo to be considered . The Capacity of each FA Silo - 1800 tonnes.

Datasheet of FLY ASH SILO: 46 of 52 Effective Capacity of each silo: 1800 m3

Vol-III/Ch:21 Ash Handling System

Vol-III/Ch:21 Ash Handling System

Owner's Reply

In absence of clarity, bidder understand that all the vacuum pumps, its sump pumps are located near ESP first field of both the units.

Vacuum pumps for each unit shall be situated under the ESP 1st 6 of 52 field (Near buffer hopper towers).

Vol-III/Ch:21 Ash Handling System

21.3.1, d)

Statement of Prebid Queries & Clarification

46 of 52 Datasheet of FLY ASH SILO: Effective ash storage shall be considered at min 750mm below soffit of silo roof beam with stored ash having a positive angle of repose

9 of 52 One adequately sized maintenance building.

Angle of repose for fly ash seems to be on higher side as per past project experience. Bidder envisage 18 Deg C angle of repose for fly ash silo storage calculation. Bidder is requested to relook and issue amendment.

In absence of clarity, bidder understand that clear free board above maximum ash level shall be 700 mm as per Sr. no. 1.4.12 of silo datasheet. Owner is requested to confirm bidder's understanding.

The stated tender clause shall be "Less than or equal to 30 mg/Nm3"

Angle of repose for FA Silo is 18o

The Clear Free board above maximum ash level shall be 700 mm as per clause 1.4.12 vol. III, Chapter 21.

Owner is requested to review and issue amendment suitably.

Agreed. It should be Less than or equal to 30 mg/Nm3

Please clarify the purpose of dedicated AHP maintenance building. Common plant maintenance building can be used to carry out AHP maintenance activity. Owner is requested to review and revert.

The provision of AHP maintenance building stands deleted.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 88

Section / Part / Chapter / Volume

Clause No.

Vol-III/Ch:21 Ash Handling System

21.3.4, f)

111-13-5202

-

Page no.

Bid Specification Stipulation

9 of 52 another set of seal water pumps at later date to enable dispose slurry to new ash dump area or rising existing ash pond dyke height. -

Flow diagram of ash water and slurry system: HP and LP seal water pumps are shown in flow diagram

Statement of Prebid Queries & Clarification

Owner's Reply

As per executed project data, each ash slurry pump will require approximately 8 to 10 m3/hr sealing water. Considering smaller sealing water demand, bidder envisage total (2) nos. seal water pumps for existing working four nos. ash slurry disposal pumps instead of Four (4) nos seal water pumps(2 LP seal and 2 HP seal pumps). The Provision as per bidding specification shall However, for future ash slurry pumps' sealing requirement will be mitigated prevail. by dedicated by another set of sealing water pumps. Request bidder to please confirm bidder's understanding.

89

90

91

92

Vol-III/Ch:21 Ash Handling System

21.3.4, i)

9 of 52 All pipe racks shall have walkway of 600 mm width.

Vol-III/Ch:21 Ash Handling System

21.2.3

2 of 52 Buffer Hoppers shall have a storage capacity of 30 M3 (minimum) (or 20 minutes accumulation of FA from one vacuum conveying stream, whatever is higher)

Vol-III/Ch:21 Ash Handling System

21.8.1, f)

27 of 52 Filter Separator cum Buffer Hoppers each having ash storing capacity of minimum 30 M3

Vol-III/Ch:21 Ash Handling System

21.4

Vol-III/Ch:21 Ash Handling System

21.2.10

Vol-III/Ch:21 Ash Handling System

21.8.2.4

Vol-III/Ch:21 Ash Handling System

21.8.2.5, (B)

Vol-III/Ch:21 Ash Handling System

21.3.1, (h)

50 of 52 DATA SHEET OF BUFFER HOPPER Capacity: 20 M3 for each Buffer Hopper (one for each vacuum conveying stream )

Bidder envisage walkways on pipe racks where ash pipe are laid. However, bidder does not envisage any walkways on pipe rack where water pipes and utility pipes are laid. Owner is requested to relook and confirm bidder's understanding.

Confirmed.

There is an ambiguity in Fly ash Filter Separator cum Buffer Hopper as per referred tender clauses. Request owner to please clarify and confirm the Fly ash Filter Separator cum Buffer Hoppers shall have Buffer Hopper effective storage capacity. 15 minutes accumulation of FA from one vacuum conveying stream.

6 of 52 Drain Pumping System Drain pumps are not specified AHP compressor house.

There is an ambiguity for drain pumps requirement for AHP compressor house as per referred tender clauses. Owner is requested to check and confirm the requirement of AHP 29 of 52 In compressor house area, total two drain pumps (one working and compressor house drain pumps. one standby) shall be provided.

2 Drain Pumps (1+1) shall be provided for AHP Compressor House.

30 of 52 One (1) recovery water pipe of suitable dia from Ash disposal area As per flow diagram ash clariflocculator system (111-13-5206), ash pond recovery pipe shall be terminated into AHP clarifier only. Also, normal to the top of clarifier / Ash Water sump suspended solids in ash pond recovery pipes are specified as 1000 ppm. In view of this, it is not envisaged to terminate recovery water pipe into Ash 6 of 52 Equipment Sizing Criteria: Water sump. Suspended solids in recovery water:1000 ppm (normal) Request owner to relook and issue suitable amendment for the same.

Ash pond recovery pipe shall be terminated into AHP clarifier only.

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Section / Part / Chapter / Volume

Clause No.

Page no.

93

111-13-5202

-

-

Vol-III/Ch:21 Ash Handling System

21.8.2.5, (F)

30 of 52 Four (4) LP Water Pumps (2W+2S/B) for two (2) units

Vol-III/Ch:21 Ash Handling System

21.8.2.5, (J)

30 of 52 One (1) over-ground adequately sized Ash Water Sump (RCC)

Bid Specification Stipulation Flow diagram of ash water and slurry system: Three (3) LP Water Pumps (1W+2S/B) for two (2) units

Statement of Prebid Queries & Clarification As per referred tender clause and AHP flow diagram, there is a contradiction in quantities of LP water pumps. Request owner to relook and issue amendment suitably.

94

Owner's Reply 2W + 2 S/B for both units as per clause 21.8.2.5 (F) mentioned in bidding specification. Shall be followed.

Bidder envisage ash water sump (Plant area) and ash water recirculation/recovery water sump semi-over ground or above ground as per layout feasibility.

Confirmed.

Request owner to accept bidder's understanding. 95

96

Vol-III/Ch:21 Ash Handling System

21.2.9

5 of 52 The instrument air supply for remote location e.g. silo shall have suitable air receiver along with moisture separator aided with maintenance free auto drain trap.

There is an ambiguity regarding quantities and location of AHP IA compressors as per referred tender clauses and AHP flow diagram. Also, check the quantities of the IA receivers specified in cl. No. 21.8.3.5.

Vol-III/Ch:21 Ash Handling System

21.8.3.1

30 of 52 3 x 100% duty Oil free Screw type Instrument Air Compressorstotal (1 W/unit + 1 S/B) for main plant area IA demand.

Request Owner to revisit and issue suitable amendment.

Vol-III/Ch:21 Ash Handling System

21.8.3.2

30 of 52 2x100% duty Oil free Screw type Instrument Air Compressors-total (1 W + 1 S/B) for FA Silo Area.

Vol-III/Ch:21 Ash Handling System

21.8.3.5

111-13-5203

-

31 of 52 Five (5) Air Receivers of 5 M3 size 3 x 100% duty Oil free Screw type Instrument Air Compressors for FA silo area -

Vol-III/Ch:21 Ash Handling System

21.9.3

97

21.12.2

111-13-5205

-

31 of 52 Datasheet of vacuum pumps: motor capacity shall be suitable to handle same capacity of air at 240 Deg C

2x100% duty Oil free Screw type Instrument Air Compressors - total (1 W + 1 S/B) for FA Silo Area.

ESP hopper ash temperature shall be 150 Deg C as per boiler OEM recommendation as per past project experience. Hence, vacuum pump conveying air temperature will never reach upto 240 Deg C. In view of this, bidder request owner to revisit the criteria for vacuum pump motor selection.

35 of 52 The ash slurry disposal pipelines shall be provided with adequately Bidder does not recommend any drains and vents along with valves in ash sized drain connections with blind flanges (with valves) at lower slurry disposal lines as same will be chocked with ash. Hence, fluid within the most location and vent connections with blind flanges (with valves) ash slurry pipes can neither be vented nor be drained during coarse of time. at top most location as per the final layout requirements.

-

3 x 100% duty Oil free Screw type Instrument Air Compressors-total (1 W/unit + 1 S/B) for main plant area IA demand.

200oC

Confirmed.

Flow diagram of ash water and ash slurry system: drain and vents are shown in ash slurry disposal pipelines.

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Section / Part / Chapter / Volume Vol-III/Ch:21 Ash Handling System

Clause No. 21.2.1

21.2

21.16

21.2.3

99

21.2.2

111-13-5201

-

111-13-5205

-

21.2.2

Vol-II, Ch: 8 5.27, (C)

100

Vol-III/Ch:21 Ash Handling System and AHP Flow diagram

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

2 of 52 bottom ash hopper having a hold up volume to store bottom ash, Considering the ash content of 50% in worst coal, it is not possible to provide Economiser and SCR ash generated for a period of minimum eight eight (8) hour bottom ash hopper storage capacity (BMCR Worst coal). (8) hours. Hence, bidder envisage to consider bottom ash cleaning twice in a shift of eight (8) hours. Accordingly, bidder envisage five (5) hours bottom ash 2 of 52 The system shall be designed to cater for 100% BMCR and 50% hopper effective storage capacity to store bottom ash and eco. ash. whereas, The Provision as per ash content in worst coal. coarse ash (SCR hopper ash and APH hopper ash) is envisaged to disposed Bidding Specification shall Prevail. in wet mode as mention in Sl. No. 99 below. 38 of 52 Datasheet of BA hopper Minimum effective ash storage capacity of BA hopper: Please confirm bidder's understanding. 8 hours (Bottom Ash + Economiser Ash + SCR ash) Owner has specified Vacuum type Pneumatic conveying of APH ash as per referred tender clauses. Bidder does not recommend APH hopper ash conveying through vacuum type Pneumatic conveying system as APH ash is coarse in nature and these ash collection hoppers are located at higher In case flushing apparatus system is not feasible for SCR hoppers, elevation. Hence, vacuum type pneumatic conveying of APH ash causes frequent line chocking problems and longer cleaning time during plant 2 of 52 then a separate coarse ash system shall be provided so as to remove the SCR ash parallel to Bottom ash. Ash slurry from SCR operation. In view of this, bidder suggest following wet type lean slurry disposal system for APH ash and SCR ash conveying which is nowadays hoppers shall be routed to a coarse ash tank (located in Boiler being followed by NTPC and other state electricity board. area) and pumped further to ash slurry sump using coarse ash Owner is requested to review and accordingly issue amendment for the same. SCR, APH & Duct ash slurry pumps (1W+1S per unit). disposal in slurry form "The ash collected in APH and SCR hoppers will be removed twice in a shift acceptable. The same Flow diagram of BA and Eco ash handling system: of eight (8) hour in sequence after bottom ash and economizer ash removal 4 nos. SCR hopper ash terminated into BA hopper shall be removed once a of all units. The ash from air preheater shall be removed by feeder ejectors to shift. BA hopper capacity a slurry tank . The slurry from the tank shall be evacuated by means of jet Flow diagram of Fly ash handling system: shall be for 8 hours only. 5 pump to the sump of ash slurry disposal pump house. 4 nos. APH hopper ash conveyed through vacuum type dry FA hours capacity is not Considering twice operation, BA hopper effective storage capacity shall be system acceptable. five(5) hours." Owner is requested to review proposal and issue suitable amendment (flow 2 of 52 (SCR hopper ash )coarse ash shall flow to respective bottom ash scheme, design basis including cleaning time, Material of construction of hopper through adequately sized and sloped pipe….. associated items etc.) (B) SCR ash handling system: 37 of 78 SCR hoppers will drop continuously into bottom ash hopper through vertical pipes, flushing connection, flushing equipment in form of slurry. 2 of 52 Fly ash collected in Air Pre-heater (APH), Duct Hoppers and Electrostatic Precipitator (ESP) hoppers and stack hoppers shall be transported pneumatically under vacuum

no. of Ash collection hoppers and their locations i.e at inlet duct hopper, at outlet duct hopper…etc

Bidder understand that no. of Ash collection hoppers and their locations shall be as per boiler OEM recommendation. Confirmed. Owner is requested to confirm bidder's understanding.

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Section / Part / Chapter / Volume

Clause No.

Page no.

101

111-13-5205

-

-

102

Vol-III/Ch:21 Ash Handling System

21.8.2.3

Bid Specification Stipulation Flow Diagram of FA handling System: Vacuum type pneumatic system is proposed for stack ash hopper ash conveying.

29 of 52 Normally slurry pipes shall be on pipe rack in plant boundary & on pipe pedestal outside plant boundary. There shall be four (4) cross country slurry disposal pipes for two units routed on pipe rack pedestals

Statement of Prebid Queries & Clarification

Considering the higher conveying length of stack ash hopper to buffer hopper tower, stack ash conveying conveying through vacuum type FA conveying system is not feasible. For such a higher conveying length vacuum system Agreed. shall not operate satisfactorily and frequent line chockage will happen. Vacuum system stands Hence, bidder envisage manual unloading of stack ash hopper periodically deleted for stack hoppers. via truck. Request owner to relook and issue amendment. In the absence of clarity in technical specification regarding the slurry disposal pipe routing arrangement, bidder envisage following arrangement. 1. BA slurry ash slurry disposal pipes from BA hopper/coarse ash slurry tank to nearest pipe rack shall be routed on the RCC pedestal upto slurry sump. Request owner to please confirm bidder's understanding.

vol-III/Ch 33: Plant Layout Requirement 103

104

33.4, 41)

3 of 52 Fly ash generated in 8 hours shall be evacuated in 5 hours 20 minutes (including time for line purging etc).

21.3.1

8 of 52 Evacuation Time: Fly ash (ESP & APH Ash) : 5 hrs in a shift of 8 hrs

5.27, (C)

111-13-5203

-

Vol-III/Ch:21 Ash Handling System

21.22

There is a ambiguity in Fly ash cleaning time as per referred tender clauses. Owner is requested to relook and issue amendment.

FA removal time - 5 hours.

(C) Fly ash extraction & conveying system 37 of 78 The fly ash collected in each unit in every shift of eight (8) hours corresponding to specified ash collection rates shall be removed in five (5) hours. -

Flow diagram of fly ash silo area: ACW water is shown for AHP IA compressor cooling

44 of 52 Instrument air compressor datasheet : Refer Chapter 23, vol-III

23.4.12 Vol-III/Ch:23 Compressed Air System

Shall be decided during detail engineering depending on the layout.

12 of 15 41) Ash slurry pipe lines shall be routed on pedestals except at road/rail crossings where pipe culverts shall be provided. Minimum height of pedestal shall be 1000 mm from FGL.

21.2.3

Vol-II, Ch: 8

Owner's Reply

5 of 20 Compressed air system equipment requiring DMCW cooling water shall be capable of operation at design capacity with DMCW cooling water inlet temperature subject to a maximum of 38ºC (Indicative).

There is an ambiguity for type of cooling water for AHP IA compressor as per referred tender clauses and flow diagram. Request owner to recheck and confirm the source of cooling water for AHP IA compressors. DMCW Water for compressor cooling.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 105

Section / Part / Chapter / Volume Vol-III/Ch:23 Compressed Air System

Clause No. 8.3

21.33 Vol-III/Ch:21 Ash Handling System

Page no.

Bid Specification Stipulation

19 of 20 Technical Datasheet of plant air compressors; 8.3 INTERCOOLER, AFTERCOOLER, MOISTURE SEPARATOR

44 of 52 Conveying air compressor datasheet : Refer Chapter 23, Vol-III

-

-

Plant air compressors

-

-

Flow diagram of fly ash silo area: silo area drain to tube settler

Statement of Prebid Queries & Clarification Bidder understand entire plant air compressor chapter can not be followed for AHP conveying air compressors (8 Nos.) as these compressors shall be selected considering the ash conveying process parameters. Hence, VolIII/Ch:23 Compressed Air System can not be used for AHP conveying air compressors. In view of this request, owner to please provide AHP specific compressor datasheet for ash handling system.

Vol-III/Ch:23 Compressed Air System 106

111-13-5203

Bidder understand that tube settler plant is not applicable for ash handling system. Request owner to please confirm bidder's understanding.

107

108

111-13-5204

111-13-5205

-

-

-

-

Flow diagram of fly ash system- buffer hopper to fly ash silo: "Ash vessel enlarged view"

Bidder understand that "Ash vessel enlarged view" shown in flow diagram of fly ash handling system is for information only. Same shall be as per AHP OEM proven technology and same shall be submitted to owner during detail engineering for approval. Owner is requested to confirm bidder's understanding.

Flow diagram of fly ash system Owner has connected ESP fluidizing line to vacuum Fly ash conveying line

As per referred FA flow diagram, Owner has connected ESP fluidizing line to vacuum Fly ash conveying line along with pneumatic type branch isolation valves. Request owner to relook and issue suitable amendment of flow diagram.

Owner's Reply

No. of stages of Compressor shall be as per Ash Handling System design. All other technical parameters shall be as per specification Chapter 23 (as applicable).

Silo area drain shall be routed to AHP clarifier.

Confirmed.

Drafting mistake. Stands deleted.

109

111-13-5205

-

-

Flow diagram of fly ash system As per the connection shown for Vacuum conveying FA lines to each ESP hoppers, it seems that each FA vacuum conveying lines are not equally loaded with fly ash.

As per FA flow scheme, it seems that each FA vacuum conveying lines are not equally loaded with fly ash. Bidder understand that the shown fly ash vacuum conveying line connection to each ESP hoppers are tentative and same shall be connected as per AHP Confirmed. OEM recommendation based on ESP design (no. of hoppers) and same shall be submitted to owner for approval during detail engineering. Owner is requested to confirm bidder's understanding.

110

111-13-5206

-

-

Flow diagram of clariflocculator system of AHP Owner has shown AHP clarifier sludge into ash dyke

Bidder understand that AHP clarifier sludge shall be terminated into ash slurry sump for further disposal into ash dyke as the AHP clarifier plant is located in plant side. Owner is requested to confirm bidder's understanding.

To ash slurry sump.

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Section / Part / Chapter / Volume

Clause No.

Page no.

111

Vol-VI/Ch:15 AHP

15.3

2 of 2

112

113

vol-III/Ch 33: Plant Layout Requirement

vol-III/Ch 33: Plant Layout Requirement

33.4, 31), VI)

33.4, 41)

15.1

115

vol-III/Ch 33: Plant Layout Requirement

33.10, b)

1 of 2

The top level of the pipe pedestals shall be 300mm above the formation level

14 of 15 b) Space for additional two (2) nos. fly ash silos to be added in future in fly ash silo area.

Vol-VI/Ch:15 AHP

15.1

1 of 2

Vol-VI/Ch:15 AHP

15.2, vi)

1 of 2

RCC paving in Silo area

Vol-VI/Ch:15 AHP

21.2.4.2

4 of 52 One (1) ash slurry pumping series shall be working for bottom ash/coarse ash/wet fly ash slurry disposal of each unit with two (2) series as common standby for 2 units.

-

Bidder envisage following. Request owner to review and confirm bidder's understanding. 1. Suitable grating will be provided only at the location of coupling /pipe joint . 2. We understand that required grating will be provided only on the tier containing ash conveying ( FA & BA ) pipes. No grating is envisaged on the tier where all water and air pipes will be installed.

12 of 15 41) Ash slurry pipe lines shall be routed on pedestals except at In absence of clarity amongst the referred clauses, request owner to confirm road/rail crossings where pipe culverts shall be provided. Minimum the pedestal height required for ash slurry pipes from FGL height of pedestal shall be 1000 mm from FGL.

development of silo area (including paving, fencing, access roads,

Flow diagram: 111-135202

Statement of Prebid Queries & Clarification

Ash Pipe Supporting Structure: Being a green field project, the referred clause is not applicable for this Ash pipe from plant area to Ash Dyke will be supported on existing project. pedestal. Modification and strengthening of existing pedestals (wherever required) is in the scope of Bidder. Please confirm.

11 of 15 31, VI) Wherever ash handling pipes are routed on the trestle, grating platform all along the length and width of the trestle shall be provided. Further, one walkway of 600mm width shall be ensured on the tier meant for routing the ash handling pipes.

Vol-VI/Ch:15 AHP 114

Bid Specification Stipulation

-

Total working ash disposal slurry chain: 3 nos and standby: 1 no

In absence of clarity amongst the referred clauses, Bidder understanding that paving, fencing, access roads shall be provided for 4 nos. FA silos only. Owner is requested to confirm bidder's understanding.

Discrapancy observed in referred clauses for nos working and standby ash disposal slurry chains. Bidder understands that ash disposal slurry chain shall be considered in line with referred clause 21.2.4.2 of Vol-VI/Ch:15 AHP.

Owner's Reply

Confirmed.

Confirmed.

Pedestals shall be 1000 mm from FGL.

The provision as per bidding specification shall prevail.

As per bidding Specification in clause no.21.2.4.2 of Chapter 21 AHP.

Owner is requested to clarify the same.

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Section / Part / Chapter / Volume

Clause No.

116

Volume III, Chapter 33

33.10-a

14 of 15 Space for additional two (2)nos. pumps to be added in future in Ash Slurry pump House building.

Volume III, Chapter 21

21.8.2.2

28 of 52 Total four (4) sets of slurry pumps each set comprising suitable & optimum No. of stages (provision for incorporating at least one no. future stage to be made)

Volume VII, Tender Drawings Mech Volume II, Chapter-1 Intent of Specification

117

E3 118

Volume III, Chapter 21

Flow Diagram Ash Water & Slurry System 1.0

21.27 & 21.29

RAW WATER INTAKE SYSTEM Volume III, Chapter 4.0 4.2

Page no.

Bid Specification Stipulation

111-13- One future pump for each series is indicated (total 4nos of future 5202 pumps.)

Statement of Prebid Queries & Clarification There is a discrepancy in AHP facilities requirement for future unit (660 MW) as per referred tender clauses. AHP technical specification(ch:21) and flow diagram do not mention any requirement of AHP equipment envisaged for future unit. e.g. As per AHP technical specification(ch:21) and flow diagram, ash slurry pump house shall house total four (4) series of ash slurry pump chains/series. Whereas as per vol-III, ch:33 and vol-II referred clause, owner is asking for future augmentation/integration & interconnection of AHP.

Bidders shall note that one (1) more unit of 660 MW may be added Owner is requested revisit the requirement of AHP equipment provision for future unit (660 MW) and describe the same in AHP technical specification in future by the EMPLOYER as an expansion unit for possible 5 of 12 augmentation of the station….. present 2x660 MW units for future along with AHP flow diagram. augmentation/integration & interconnection of corresponding system 45 of 52 Disc/Dome/Cone/Plate: 3 mm thk. SS-410/420 heat treated to 350 & 46 of BHN 52

2 of 3

It is proposed to locate the Raw Water Intake Structure at SITE 3 which is 350 M downstream of the State Govt Intake structure (as per enclosed WAPCOS final report on water drawl study).

Owner's Reply

AHP of future unit need not be considered in the present ash handling system design. No integration & interconnection.

Bidder proposes ACI 350BHN MOC of Dome as per OEM standard. Please confirm acceptance.

Agreed.

The report mentioned in the specification (WAPCOS water drawl study) is missing. Refer Addendum -01. Please furnish the same for our information.

119

120

Volume III, Chapter 4.0

Volume II Ch 1 : Intent of Specification Volume III, Ch 5 : Water Treatment Plant

-

2 of 3

Missing details in Raw water intake system

In the absence of inputs, we request Owner to provide the following details of raw water intake arrangement for estimation. 1. Tentative locating coordinates of raw water intake well and pump house 2. High flood level of river 3. Maximum draw down level of river 4. Maximum and minimum water level of river 5. Tentative pipe corridor from raw water pump house to raw water reservoir located within plant boundary 6. Contour of intake area and pipe corridor 7. Grade level of intake pump house area

1.2

6 of 12 Raw water reservoir (5 days)

Discrepancies observed in referred clause.

5.1

Raw Water Reservoir of 6 days storage approx. capacity 530,000 2 of 14 cum in two compartments

Owner to fix the raw water reservoir storage capacity as 5,30,000 cum and issue suitable amendment.

1 to 4: Please refer addendum. 5: In scope of Bidder. 6&7: During detail engineering.

The capacity of raw water reservoir-530,000 M3.

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Section / Part / Chapter / Volume Volume III, Chapter 15.0

Clause No.

Page no.

15.3 (j)

4 of 49

11.8

8 of 16

Volume VI, Chapter 11.0

122

E4 123

2 of 3

Volume VI, Chapter 06 6.17.00 (3)

8 of 9

Volume III ANNEXURE- I Ch 5 : Water Treatment

j) Stop log gate and coarse screens at up stream of CW & ACW pumps.

Statement of Prebid Queries & Clarification Discrepancy between referred clauses. Bidder understands that only coarse screen shall be required.

Each sump shall be provided with stainless steel (SS 316L) groove for inserting coarse screen, fine screen and stop logs. Grooves for Please confirm. stop log shall be provided before and after the screen.

Volume III, Chapter 4.0 4.7 (j)

WATER TREATMENT PLANT Volume II Appendix – I: Ch 2 : Project Information

Bid Specification Stipulation

4 of 7

Owner's Reply Grooves for Stoplog Gates & Coarse Screens shall be provided. Screens shall be permanently installed while stoplog gates will be installed in a sump during maintenance.

j) Stop log gates, trash racks, coarse screens as required shall be Discrepancy between referred clauses. installed in the Raw water Intake structure. The specification of the Bidder proposes to use stoplog gates / gate valve to iosolate incoming water. gates and screens shall be same as described in Chapter-15 for CW system. Bidder also proposes to use coarse screen/ crib for screening incoming water. Water Intake well shall generally be circular in shape of required diameter to house vertical wet pit pumps of required capacity, switchgear room, travelling screen, stop log gates, monorail and trash racks.

Please confirm

Raw Water Analysis

The Raw Water Quality mentioned in Project Information and Water Treatment Plant Section is different, with regards to Turbidity, pH etc.

6 of 14 RAW WATER ANALYSIS

Refer addendum -01

Due to referred discrepancies, Owner is requested to confirm which clause to Refer amendement -04. be referred for Raw Water Analysis.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 124

Section / Part / Chapter / Volume Volume II General & Schedules Ch 4 : Provenness

Clause No. 4.10

Page no.

125

Volume II, Chapter 2.0 & Volume III, Chapter 5.0

Appendix-1 & Annexure-1

Statement of Prebid Queries & Clarification

Owner's Reply

10 of 40 Water Pre-treatment Plant & Liquid Effluent Treatment Plant Due to discrepancy in referred clause, bidder will follow the description The Bidder/its sub-vendor should have designed, supplied, erected mentioned in Attachment - 3K on Page 144 of 322. and commissioned at least two (2) water/waste water treatment Please confirm. plants, each with a capacity of not less than 2000 Cu.m/hr, comprising of clarifiers/tube settlers/ thickeners or a combination thereof including civil works. The plants should have been in successful operation for at least one (1) year prior to the date of Techno- Commercial bid opening.

ATTACHMENT - 3K -

Bid Specification Stipulation

144 of 322

Qualification details for Water Pre-treatment Plant & Liquid Effluent Treatment Plant. In terms of clause no. 4.10 of Chapter 04, “Provenness” , Volume II, We/our sub-vendor confirm that, we have designed, supplied, erected and commissioned at least two (2) numbers of water/waste water treatment plants, each with a total capacity of 1000 cum/hr. (minimum), comprising of clarifiers/tube settlers/thickeners or a combination thereof including civil works. The plants should be in successful operation for atleast one (1) year prior to the date of Techno-commercial bid opening, as per following details:

4 of 7 Colloidal silica : Detail missing & & 6 of 14 Colloidal silica : Traces

Chapter 4 Provenness shall prevails.

There is discrepancy in Colloidal silica value mentioned in Raw water Analysis. It is mentioned as "Traces" in Volume III and not specified in Volume II. Bidder understands that colloidal silica traces mentioned in Vol. III corresponds to non deductible limit and hence no separate treatment/equipment is envisaged for the same.

Confirmed.

Please confirm bidder's understanding. 126

Volume II, Chapter 2.0 & Volume III, Chapter 5.0

Appendix-1 & Annexure-1

4 of 7 Turbidity : 154 NTU & & 6 of 14 Turbidity : 500 Silica scale

Turbidity of raw water is mentioned as 154 NTU in Volume II. Whereas, the same is mentioned as 500 Silica scale in Volume III. In general, turbidity is measure in NTU and hence, bidder will consider the turbidity value as mentioned in Volume II (i.e. 154 NTU).

Refer amendement -04.

Please confirm.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 127

Section / Part / Chapter / Volume

Clause No.

Volume II, Chapter 2.0 & Volume III, Chapter 5.0

Appendix-1 & Annexure-1

Page no.

Bid Specification Stipulation

4 of 7 Total suspended solids : 122 ppm & & 6 of 14 Total suspended solids : Detail missing

Statement of Prebid Queries & Clarification Total suspended solids (TSS) of raw water is mentioned as 122 ppm in Volume II. Whereas, the same is not included in raw water analysis given in Volume III. Bidder will consider TSS value as 122 ppm as mentioned in Volume II of specification.

Owner's Reply

Design TSS shall be 500 ppm

Please confirm. 128

129

Volume III, Chapter 5.0 Data sheet, 3.d, 7 & 8 of Rated capacity of PT plant equipment: 4.c, 5.b, 6.d 14 Stilling chamber : 3800 cu.m/h Parshall flume : 2200 cu.m/h Flash mixer : 1900 cu.m/h Clariflocculator : 2200 cu.m/h Volume III, Chapter 5.0

130

Volume III, Chapter 5.0 5.3.q

E5 131

FLUE GAS DESULFURISER Volume II, Chapter 2.0

132

Volume II, Chapter 2.0

5.3

3 of 14 Two (2) (1W+1S) wall mounted chlorinator system having capacity Owner has mentioned the requirement of eight (8) nos. of chlorine ton of 25 kg/hr for raw water chlorination with eight nos. of tonners. containers in the specification. However, there is no mention about chlorine absorption system in the specification. Considering eight (8) nos. of ton containers, scrubber system is mandatory. Owner is requested to confirm the requirement of chlorine gas scrubber for raw water system and issue suitable amendment. 4 of 14

-

It is observed that there is a discrepancy between the rated capacity of Stilling chamber (3800 cu.m) and Parshall flume (2200 x 2 = 4400 cu.m/h). Similar mismatch is observed between flash mixer (1900 x2 = 3800cu.m/h) and clariflocculator (2200 x2 = 4400cu.m/h) . Owner is requested to clarify the same.

-

One (1) platform digital type weighing scale of 500 kg capacity. An electric hoist with electric driven travelling trolley of 1 Tonne capacity in the chemical house.

As the ton containers load capacity is approx. one (1) ton, weighing scale of 500 kg and electric hoist of 1 tonne will not be sufficient. We propose weighing scale of 1000 kg and electric hoist of 2 tonne capacity. Please confirm.

Missing details in Project information

Owner is requested to provide Limestone analysis report for Flue gas desulphurisation (FGD) plant design.

Missing details in Project information

Owner is requested to provide Trace element analysis of coal (including mercury, arsenic, selenium, etc.) for FGD waste water system design.

The Provision as per Bidding specification shall prevail.

Confirmed.

500 kg capacity weighing scale & 1 tonne crane is for chemical handling only. For Cl2 Tonner handling separate 3 T Crane is to be provided.

Refer addendum -01 Revised coal analysis shall be submitted through ammendment.

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134

135

Section / Part / Chapter / Volume Volume III Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Clause No. 6.11.3.2

Volume III Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.11.3.5

Volume VII, Mechanical

111-12-3504 EFFLUENT TREATMENT PLANT-Model

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

E6

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

53 of 54 Physico- chemical treatment is to be provided in order to reduce total suspended solids, adjust the pH, and reduce the heavy metals. The treated waste water shall be pumped to ash slurry sump as well as to the ash pond through two (2) (1w+1s) Treated FGD waste water pumps The solid sludge shall be disposed of suitably.

Specification calls for suspended solids removal and heavy metal treatment in addition to pH correction. Since the treated water is sent to ash pond, the same are not necessary, provided proper lining is given in ash pond to avoid leaching of heavy metals and to prevent ground water contamination. As per NTPC specification, only pH correction is considered for FGD waste water treatment before disposing to ash pond. Request Owner to re-analyse the treatment scheme mentioned in the specification with respect to our above consideration. However, if Owner insist to consider FGD waste water treatment, then various chemical dosing (like lime, organo sulfide, coagulant, polymer, etc.) and multiple clarifier arrangement along with sludge removal and disposal system are required. In order to keep all bidders at par, we request Owner to provide a detail specification for this system with process flow diagram.

54 of 54 Bidder shall provide all the consumables including chemicals till the provisional handing over and additional chemicals of two (2) months consumptive requirement

Bidder understands that the chemicals have to be provided till provisional handing over of Unit#1. Please confirm.

6.11.3.2

6.1.2 6) Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

Page no.

-

Ash slurry sump is not shown in referred P&ID

Owner's Reply

The Provision as per bidding specification shall prevail.

The Provision as per bidding specification shall prevail.

Owner to note that the treated waste water from FGD shall be pumped to ash slurry sump only, which in turn shall be led to the Ash Pond. Please note that no separate provision shall be made for transferring the same directly to Ash Pond.

53 of 54 Physico- chemical treatment is to be provided in order to reduce total suspended solids, adjust the pH, and reduce the heavy Please confirm. metals. The treated waste water shall be pumped to ash slurry sump as well as to the ash pond through two (2) (1w+1s) Treated FGD waste water pumps The solid sludge shall be disposed of suitably. 3 of 54 The gypsum slurry from absorber shall be pumped by dedicated gypsum bleed pumps to a Gypsum Dewatering system consisting of dual streams (in series) of primary and secondary dewatering equipments. The waste water from the system shall be discharged to effluent treatment plant.

Confirmed.

SERVICE CUM POTABLE WATER SYSTEM

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137

Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 7.0 7.2.2.a & & Volume VI, Flow Flow diagram diagram Potable water Potable water system system & & Volume VI, Flow Flow scheme scheme DM plant DM plant 7.2.1 c) Volume III : Mechanical Works Ch 7 : Service cum Potable Water System

7.2.2 d)

Page no.

Bid Specification Stipulation

3 of 7 & Sh.1 of 1 & Sh. 1 of 3

Two 2 (1W+1S) Potable water pumps (Cap-10M3/hr minimum) taking suction from Potable water storage tank & supplying Potable water to cater Plant requirement. & Potable water pumps quantity : 3 (2W + 1S) & Potable water pumps quantity : 2 nos.

Specification write-up and DM plant flow scheme shows 2 (1W+1S) nos. of potable water pumps for plant potable water requirement. However, potable water system flow diagram shows 3 (2W+1S) nos. of potable water pumps for plant, which is contradicting with the earlier mentioned documents. Bidder considers 2 (1W+1S) nos. of potable water pumps for plant potable water requirement inline with write-up and data sheet. Please confirm our understanding.

2 of 7

7.2.1 Service water system c) O/H service water HDPE/Polypropylene tanks of 5 cum effective capacity located on roof of DM plant, Boiler building Unit # 1, Boiler building Unit # 2, Fire Station Building, ETP Building, Crusher House, Hydrogen Generation Plant Building Ash Silo Area, Wagon Tippler Area / CHP Building, Administrative Building (as mentioned elsewhere) and as provided as per P&ID – Service Water System, etc.

Bidder understands that the terminal point for Potable water & Service water for Admin Building will be upto plant boundary only.

139

Vol-III, Ch 7 : Service cum Potable Water System

Vol-III, Ch 7 : Service cum Potable Water System

Please confirm acceptance.

7.2.2, j)

2 of 7

3 of 7

O/H service water HDPE tanks of 2.5 M3, 2.0 M3 effective capacity located on roof of JNT # 10, Stores, Workshop, Service Building, Compresser House, ESP Control Room , AHP Control Room, Ash Pump House, DG Set Room, CPU Regeneration Building, CW Pump House, and as provided as per P&ID – Servoce Water System, etc.

Bidder understands that O/H service water HDPE tanks of 2.0 m3 effective capacity shall be provided and not of 2.5 m3.

Piping and instrumentation as indicated in the P&ID for service water system. (Drg. No. 111-12-3401)

There is typo error in referred clause. The referred drawing is for potable water system and not for service water system.

Please confirm bidder's understanding.

Please confirm. E7 140

DM PLANT Volume III Mechanical Works Ch 8 : DM Plant

8.3.4

The Provision as per bidding specification shall prevail as mentioned in data sheet and clause 7.2.2(a)

Admin. Building is read as service building is located inside plant boundary. O/H Tank shall be in bidder's scope.

7.2.2 Potable water system d) O/H potable water HDPE tanks of 5.0 cum effective capacity located on roof of Fire Station, ETP Building, Crusher House, Wagon Tippler Building, Administrative Building, Ash Silo Area, etc. 7.2.1, d)

Owner's Reply

Hence, O/H tank shall not be in bidder's scope.

3 of 7

Volume III : Mechanical Works Ch 7 : Service cum Potable Water System 138

Statement of Prebid Queries & Clarification

Confirmed.The capacity of O/H service water is 2.5m3.

Agreed (in place of service water potable water system)

Bidder shall provide chemicals and consumables till Completion of facilities of 4 of 16 Bidder shall supply first charge of filter media, resein, degasser tower rings, lubricating oil, inhibitor of oil & all the consumables Unit#1. The Provision as per including chemicals till the handling over of the plant & additional bidding specification shall Please confirm. chemicals of two (2) months requirement. prevail.

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Section / Part / Chapter / Volume

Clause No.

141

Volume III, Chapter 8.0

8.2.n

2 of 16 Four (4) of Effluent Disposal pumps; Two (2) in each compartment complete with electrical drive motors and other accessories as required.

Bidder would like to propose Two (2x100%) effluent disposal pumps, that will The Provision as per be installed at a common bay for both the compartments of neutralisation pit bidding specification shall instead of Four (4) pumps as given in specification. prevail.

142

Volume III, Chapter 8.0

8.4.f

5 of 16 Ten (10) nos. of conductivity transmitters out of which 2 Nos. on each strong acid cation exchangers and 1 No. at outlet of each weak base anion & strong base anion and MB exchanger.

Weak base anion is not included in specification as well as in P&ID. Hence, Bidder understand only eight (8) numbers of conductivity analysers are applicable and the same will be considered in offer.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Confirmed.

Please confirm Bidder's understanding. 143

Volume III, Chapter 8.0

Data sheet, 6.2.v

14 of 16 Neutralised waste disposal pumps: Material of Construction - Column Pipe SS 316 - Base Plate Carbon Steel IS:2062 - Impeller Stainless Steel CF 8M - Shaft Stainless Steel SS 410 - Shaft coupling Stainless Steel SS 304 - Shaft sleeve SS 316

For neutralised waste disposal pumps, we propose Horizontal centrifugal pumps with priming arrangement and M.O.C as below: 1. Casing: Rubber lined, cast iron IS: 210 Grade FG 260 2. Impeller: Rubber lined, Cast Iron IS: 210 Grade FG 260 3. Shaft: SS 410 4. Shaft coupling Stainless Steel SS 304 5. Shaft sleeve SS 316 Stainless steel material is not suitable for this application considering below The Provision as per reasons: a) Chloride content in N-pit effluent could be in the range of 3000-5000 ppm. bidding specification shall prevail. Stainless steel is subjected to corrosion for this Chloride level. b) Effluents from DM plant collected in N-pit are not always designed with selfneutralized condition and would need pH correction time to time. N-pit effluent disposal pumps are used to recirculate the water during mixing prior to discharge of effluent, which could be acidic in nature, which again is not suitable for SS material. Considering this, it is not recommended to use stainless steel for this application.

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145

Section / Part / Chapter / Volume

Clause No.

Volume III : Mechanical Works Ch 8 : DM Plant

Guaranteed Effluent Quality from DM Plant

Volume II General & Schedules Ch 8 : Functional Guarantee & Liquidated Damages

5.30 b) 4.

Volume III : Mechanical Works Ch 8 : DM Plant

Guaranteed Effluent Quality from DM Plant

Volume II General & Schedules Ch 8 : Functional Guarantee & Liquidated Damages

5.30 b) 3

Page no.

Bid Specification Stipulation

10 of 16 S.No. Description Outlet Parameters 1. SAC Outlet Sodium Leakage ppm as NA <0.5 ..... 3. SBA Outlet Reactive Silica ppm as SiO2 <0.1 Conductivity Micromho < 5 Total Electrolyte ppm < 1

Statement of Prebid Queries & Clarification Owner to note that two clauses are mentioned for Guarantee of DM Water. Due to discrepancy, bidder will follow Clause no. 5.30 b) 4. mentioned in Volume-II, Chapter-8. Please confirm.

Provision as per VolumeIII Ch.8 data shall prevail.

40 of 78 4. Effluent from the anion exchanger shall be guaranteed as follows at rated capacity throughout the period between two regenerations: i.) Reactive silica not to exceed: Not to exceed 0.2 ppm as SiO2 ii.) Conductivity at 25 deg.C : Not more than 10 micro mhos/cm iii.) Sodium leakage through cation shall not exceed 2 ppm as CaCO3 throughout the period between two regenerations.

10 of 16 S.No. Description Outlet Parameters 4. MB Outlet Reactive Silica ppm as SiO2 <0.01 Total Electrolyte ppm <0.05 Total Hardness Nil Conductivity Micromho ≤ 0.1 at 250C pH value at 25 Deg.C 6.8 – 7.2 40 of 78 3. Effluent from the mixed bed unit shall be guaranteed to meet the following requirements, at rated capacity, throughout the period between two successive regenerations: i.) Reactive Silica not to exceed - 0.01 ppm as SiO2 ii.) Iron as Fe - Not detectable as per ASTM (ASTM-D-1068) iii.) Total Hardness - Not detectable iv.) pH Value - 6.8 - 7.3 v.) Conductivity - Not more than 0.1 micromhos/cm at 25 deg.C.

Owner's Reply

Owner to note that two clauses are mentioned for Guarantee of DM Water. Due to discrepancy, bidder will follow Clause no. 5.30 b) 3. mentioned in Volume-II, Chapter-8. Please confirm.

Provision as per VolumeIII Ch.8 data shall prevail.

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147

E8 148

Section / Part / Chapter / Volume Volume III : Mechanical Works Ch 8 : DM Plant

Volume III : Mechanical Works Ch 8 : DM Plant

Clause No. 8.2

6.2

Volume III : Mechanical Works Ch 38 : Effluent Treatment Plant

38.2.4

Volume VII Mechanical

111-12-3501 R0

CONDENSATE POLISHING UNIT Volume III, Chapter 9.0 9.6.1.ii

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

2 of 16 The DM Plant shall be supplied complete and shall include, but not limited to the following. DM Plant shall also include the Interconnecting piping, valves & other accessories. a) Three (3) Pressure Sand Filters along with 2 nos. blowers with all accessories. b) Two (2) Activated Carbon Filters with all accessories c) Two (2) Strong Acid Cation exchangers with all accessories. d) One (1) Degasser system consisting of DG tower, sump, air blowers with drives and degassed water transfer pumps with drives. e) Two (2) Strong Base Anion Exchangers with all accessories

Bidder understands that since the Weak Acid Cation & Weak Base Anion Exchanger are not specified on the DM Plant specification, hence, the same have not been considered.

14 of 16 6.2 Neutralised Waste Disposal Pumps Two (2) (1w+1s) in each compartment. i) Capacity and Head M3/hr, MWC To empty pit in four (4) Hours Transfer water to Guard Pound

Due to discrepancy observed in the referred clauses & P&ID for N-Pit waste, bidder shall transfer the N-Pit Waste directly to the Ash Slurry Sump.

4 of 19 38.2.4 DM PLANT/ CPU PLANT REGENERATION WASTE: The DM Plant/CPU regeneration waste shall be generated due to regeneration of resin beds by acid or alkali. The waste contains high amount of dissolved solids and acidic/alkaline nature based on the regeneration requirements. The effluent shall be collected in the Neutralising pit after pH correction and pumped to the ash water sump for further treatment. -

Owner's Reply

Please confirm bidder's understanding. Confirmed.

Owner is requested to confirm acceptance & issue amendment accordingly.

Confirmed.

N-Pit waste collected in CMB

7 of 19 This tank shall be provided with burn out protection, pressure relief valve, level switches, temperature indicator etc. The temperature switches provided on the tank shall control the heater. The heaters shall be sized for heating the water from a temperature of 15 to 50 deg.C within 4 hrs. C at the outlet of ejector.

We understand the term burn-out protection is referred to tank insulation for personnel safety. Insulation is not required for hot water tank as the temperature of the water inside the tank will be not exceed more than 50 °C. Agreed. Hence, the burn out protection is not considered for Hot water tank and associated pipe lines and valves. Request Owner's acceptance in this regard.

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150

Section / Part / Chapter / Volume Volume III : Mechanical Works Ch 09: Condensate Polishing System

Clause No. 9.2.1

Volume III : Mechanical Works Ch 09: Condensate Polishing System

9.6.1 ii)

Volume III : Mechanical Works Ch 09: Condensate Polishing System

3.3

Volume III : Mechanical Works Ch 8 : DM Plant

8.2, p)

Volume III : Mechanical Works Ch 09: Condensate Polishing System

9.2.3, (ii)

Page no.

Bid Specification Stipulation

2 of 19 Each unit shall have three (3) service vessels (two working & one standby) of 50% capacity design for maximum condensate flow corresponding to: Valve Wide Open condition at 1% make-up and designed condenser pressure OR HP/LP bypass charge condition OR All HP heaters are out of service

Statement of Prebid Queries & Clarification Bidder has considered that each unit shall have three (3) service vessels (two working & one standby) of 50% capacity designed for condensate flow corresponding to following condition: Valve Wide Open condition at 1% make-up and designed condenser pressure inline with all recent NTPC and SEBs projects and not for other two referred conditions.

Owner's Reply

The Provison as per bidding specification shall prevail.

Please confirm acceptance.

7 of 19 ii) For heating of alkali diluent water a hot water tank with electric Discrepancy observed in referred clauses, bidder understands that Hot Water heater adequately insulated of stainless steel construction shall be Tank for DM Plant and CPU is common in line with referred clause 3.3 of volIII, Ch-09, CPU. provided. Please confirm bidder's understanding.

151

E9 152

16 of 19 Alkali Diluent Water Heating Tank (Hot Water Tank) Common for DM Plant & CPU.

Confirmed.

2 of 16 One (1) Hot Water Tank complete with all accessories common for DM & CPU regeneration.

CW TREATMENT & CHLORINATION Volume III, Chapter 17 17.4.9

2 of 19 In addition to the dissolved solids, the influent condensate shall also contain some quantities of suspended solids (crud) derived from the corrosion of water and steam carrying pipe lines, turbine condenser and steam side of the feed water heater. The polisher beds shall be designed such that they provide sufficient filtering action to restrict the effluent crud content to less than 5 ppb. Pre filters, to be used for this purpose shall be of regenerating type.

Since technical details of pre filter are not mentioned in tender specification, bidder understands that pre filter is not envisaged for CPU.

6 of 18 For Biocide Injection System, Scale Inhibitor Injection System and Corrosion Inhibitor Injection System, all associated pipe work, fittings, valves etc. shall be stainless steel type 316 construction only.

SS 316 will not be suitable if the biocide is of oxidising type. We propose CPVC PN10 / Polypropylene (PP) pipe material for biocide, sulphuric acid, scale inhibitor and corrosion inhibitor applications.

Please confirm bidder's understanding. If pre filters are required, Owner is requested to furnish the technical details of the same.

Owner is requested to accept the proposal.

Prefilters are required.The same should be finalize during detailed engineering.

The Provison as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

153

Volume III, Chapter 17

17.4.11

6 of 18 The chemical injection pumps shall be positive displacement, simplex, constant speed, variable stroke plunger operated reciprocating type and arranged to operate under flooded suction conditions. The pump internals coming in contact with chemical shall be SS 316 (except for Sulphuric Acid service where it shall be of Alloy 20) construction.

PP / PVDF material shall also be considered as an alternative option for the subject chemical dosing pumps as the same are compatible and widely used The Provison as per in many executed projects. bidding specification shall Owner is requested to accept the proposal. prevail.

154

Volume III : Mechanical Works Ch 17 : CW Treatment & Chlorination

17.1.2

2 of 19 Scope of Supply: i. Seventy two (72) Empty chlorine Ton containers alongwith trunnion, metallic brackets and roller support for tonner with half hoods for each tonner and one (1) no. full hood.

There is a discrepancy in the quantity of chlorine ton containers between write-up and data sheet. Please confirm the actual requirement of chlorine ton containers.

1.1 (iii) 155

156

157

E10 158

Volume III : Mechanical Works Ch 17 : CW Treatment & Chlorination

5.0

Volume II General & Schedules Ch 8 : Functional Guarantee & Liquidated Damages

3.10.2

Volume II, Chapter 8.0 & Volume III, Chapter 17

5.35.5f,g & Data sheet, 17.6.1.v

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

10 of 19 Chlorine container Numbers Required Nos. Sixty eight(68) 14 of 18 Day Tank for Scale Inhibitor, Corrosion Inhibitor & Biocide

Owner to note that there seems to be a type error in the referred clause in the data sheet. The Day Tank shall be read as Storage Tank. Please confirm.

25 of 78 c) Water System Pumps (Working Pumps) xiv.) CW treatment system & Chlorination plant

Owner is requested to provide the duty factor for the referred systems.

42 of 78 f) TVC (Total Viable Count) (Micro Biological Counts) < 1.2 x 100000 counts/ml of circulating water. & 8 of 18 g) SRB (Sulphate Reducing Bacteria) <100 organisms/100 ml of circulating water. & Micro/Bio fouling conditions • Total Viable Count (TVC) : < 1 x10^5 Counts/ml • Sulphate reducing bacteria (SRB) : < 1 x10^5 Counts/100 ml

There is a discrepancy between the listed clauses for the Circulating water chemical treatment guarantee parameters. Request Owner to provide the actual guarantee parameters to be considered for bidding.

IDCT Volume III, Chapter 18 Data sheet, 1.06 19 of 21 Cold water temperature (°C) : 33 (guaranteed)

Owner's Reply

Tonners for CW Chlorination shall be 72 Nos.

The Provison as per bidding specification shall prevail.

Duty Factor is 1.0 Please Refer chapter 8 page 24 0f 78, clause3.10.2.

Bidder requests Owner not to fix cooling water inlet temperature to condenser as 33°C. Since it is an EPC project, the cold end optimization shall be left to bidder. Please confirm acceptance.

The provision as per bidding specification mentioned in Vol. III shall prevail.

The Provison as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

159

Volume III, Chapter 18

18.2

E11 160

FUEL OIL HANDLING SYSTEM Vol. VI/ Ch 02 2.6 (32.)

Vol VII 161

Page no.

Bid Specification Stipulation

3 of 21 The CT basin shall be so designed to have effective capacity (between min. water level & max. water level) to store atleast ten (10) minutes of cooling tower flow at full load operation of the unit.

4

LDO unloading, pump house, transfer pump, LDO storage tank foundation, oil water separator pit and pressurizing pump house.

111-29-0200 Rev 0

Statement of Prebid Queries & Clarification IDCT basin effective capacity shall be selected by EPC contractor based on their proven experience for 660 MW plants. Please confirm

1.1.18 (9)

22

Vol. III/ Ch 22

22.2.1

3

One (1) drain oil tank common for two (2) steam generator units in pressurizing pump house area having 10 m3 capacity and one oil transfer pump with motor.

Confirmed.

As Bidder proposed to provide common pump house for LDO unloading and pressurizing pumps, one (1) common drain oil tank of 10m3 capacity with common 2 no. (1W+1S) sump pumps of 10m3/hr capacity shall be provided for 2 units.

One drain oil tank shall be furnished to collect the oil drained from various pipes and from the equipment in the unloading pump Please confirm. house. The tank shall conform to IS:800 and IS:804. The tank shall have accessories as indicated in tender drawing and shall have minimum liquid holding capacity of 6m3. 162

The Provison as per bidding specification shall prevail.

Bidder has considered common pump house for LDO unloading pumps and LDO pressurizing pump. Owner is requested to confirm.

Plot Plan

Vol. III/ Ch 1

Owner's Reply

Confirmed.

Vol. III/ Ch 01

1.1.18 (15)

23

Two (2) nos. sump pumps with motors

Vol. III/ Ch 22

22.6 (11)

8

Two (2) nos. pumps shall be installed at sump of unloading pump house and two (2) nos at water pit of oil water separator pit

163

Vol. III/ Ch 24

24.4.3 (g)

10

LDO/HFO tanks

Bidder has considered only LDO as a main fuel for boiler start up and flame stabilization. Please confirm the Bidder's understanding.

164

Vol. III/ Ch 22

22.6

8

LDO transfer pumps

Vol VI

111-11-1300

Please note that the selected system is adequate to supply the oil to Auxiliary Boiler. Hence, separate LDO Day Oil Tank & set of 2 Nos. (1W+1S) LDO The Provison as per transfer pumps for auxiliary boiler are not envisaged. bidding specification shall prevail. Owner is requested to confirm and issue suitable amendment.

LDO transfer pumps

Bidder proposed to provide common pump house for LDO unloading and pressurizing pumps. Hence, bidder has considered two (2) nos. pumps installed at sump of unloading cum pressurising pump house and two (2) nos Confirmed. at water pit of oil water separator pit. Owner is requested to confirm. Agreed.Only LDO is considered as main fuel for boiler start up.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Volume III Mechanical Works Ch 1: SG & Auxiliaries Section 1 : Scope

1.1.18 7. (v)

22 of 47 (v) Recirculation piping around firing aisle and to the fuel oil storage Bidder doesn't envisage long recirculation from Boiler for LDO, hence, no tanks. LDO return line will be provided.

Volume VII Mechanical

111-11-1300 (R00) - FLOW DIAGRAM LDO UNLOADING SYSTEM

Owner's Reply

Please confirm acceptance and issue amendment suitably. As per fuel oil flow diagram, recirculation line from boiler is shown to day oil tank. Confirmed.

111-11-1301 Flow diagram of Fuel oil Firing System 166

Volume VII Mechanical

111-11-1300 (R00) - FLOW DIAGRAM LDO UNLOADING SYSTEM

-

1. Suction of Pressurizing Pump shown from LDO Day Tank

Bidder understands that pressurising pump suction and return line shall be connected to LDO Storage Tank and not LDO Day Tank.

2. LDO Pressurizing Pump Return shown to LDO Day Tank. Please confirm bidder's understanding. Confirmed.

111-11-1301 Flow diagram of Fuel oil Firing System E12 167

COMPRESSED AIR SYSTEM Vol. III/ Ch 23 23.4.8

5

The total Service Air requirement shall be assessed by considering Service Air for cleaning purpose is not envisaged in CHP and AHP areas considering dust environment. the following guideline: Please confirm. Y = {(2xE+F)+G+H} x [1+ (mw+ml)/100] where Y = Total service air requirement (continuous) E = Service Air requirement (continuous) for SG, TG & auxiliaries of each unit. F = Service Air requirement (continuous) for Water treatment plant and other facilities. F = 2.5 NM3/min (minimum) G= Service Air Requirement for AHP H= Service Air Requirement for CHP mw = Wear & tear margin (10%) ml = Leakage margin (10%)

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

168

Vol. III/ Ch 23

23.4.8

5

Bid Specification Stipulation 23.4.8 (i) The total Instrument Air requirements shall be assessed by the following guideline: Z = {2(A+B)+C+D} x [1+ (mw+ml)/100] ......

Statement of Prebid Queries & Clarification

Owner's Reply

Diversity factor is not specified for intermittent instrument air consumption. Diversity factor of 0.4 shall be considered for intermittent instrument air requirement as per standard engineering practice. Owner is requested to confirm.

Z = Total Instrument Air requirement The total Service Air requirement shall be assessed by considering the following guideline: Y = {(2xE+F)+G+H} x [1+ (mw+ml)/100].....

Each Service Air Compressor shall have capacity derived based on above formula or identical to that of each IA compressor whichever is higher While calculating the air requirement of bidder’s equipment/ plant/ systems for continuous requirement of service air, no diversity factor shall be considered and they are assumed to be of “Simultaneous Requirements”. The intermittent requirement of service air, if any, shall be converted into continuous requirement by considering frequency of such requirements or selecting an appropriate diversity factor and such diversity factor shall not be less than 0.6. 169

Vol. III/ Ch 23

23.5.1 (h)

7

Vol. III/ Ch 23

23.6.5

11

Vol. III/ Ch 23

Datasheet 8.2.1

18

Vol VII

111-14-6100

Diversity factor shall be 0.6.

Discrepancy is found in listed clauses. Three Unit Air Receivers, two in main plant area and one in DM plant area. Capacity of each unit air receiver in main plant area shall be minimum 10 M³ and for DM plant area it shall be minimum Request client to provide Air receiver capacity to be provided for the following 1. TG building unit air receiver 2 M³. 2. air receiver at DM plant. ... compressor house & Two (2) Nos. each of 15 m³ to be located near TG Building, shall be designed and fabricated as per applicable ASME/IS Codes. ... Two (2) – 10 Cum each- unit air receivers One (1)- 5 Cum for DM plant Flow diagram compressed air system TG building unit air receiver -each 15 M³ Air Receiver at DM plant - 2 M³

The Provison as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

170

Vol. III/ Ch 23

23.4.15

6

Each Air Receiver shall be so sized that even in the event of total stoppage of air inflow to the same, the pressure in the Air Receiver shall not fall below 5.5 kg/cm2 (g) within two (2) minutes of such stoppage, while maintaining an out flow of air at a rate equal to the rated capacity of a single compressor, during the aforesaid period. In no case, the size of each Air Receiver shall be less than that arrived from IS 7938.

As per IS: 7938, 'T' is the time for which receiver supplies air from upper to lower pressure limits. This is applicable for reciprocating compressors. In case of Screw compressors the loading & unloading of air compressors shall be carried out from the pressure transducer at discharge side of the compressor. Bleed down time 2 min. is extremely high which shall result in abnormal size of air receivers. The compressor takes not more than 23 sec. to achieve full capacity. Moreover there are receivers provided for standby compressor and, additional unit air receivers have also been asked for in the specification. So we request to optimize Bleed down time to 10 sec. in line to the requirement of all other consultant/ customer.

171

Volume III Mechanical Works Chapter - 23 : Compressed Air System

23.4.8

5 of 20 (i) The total Instrument Air requirements shall be assessed by the following guideline: Z = {2(A+B)+C+D} x [1+ (mw+ml)/100] where, A = Instrument Air requirement for SG & auxiliaries of each unit (continuous). B = Instrument Air requirement (continuous) for TG & auxiliaries of each unit C = Instrument Air requirement (continuous) for Water treatment plant and other facilities D = Station C&I requirement (continuous). mw = Wear & tear margin (10%) ml = Leakage margin (10%) Z = Total Instrument Air requirement

Bidder understands that the total Instrument Air (IA) requirement (Z)) calculated from the referred clause is for both the units and in order to arrive at the compressor capacity, the same needs to be divided by nos of working IA compressors ( i.e each compressor capacity= Z/2).

Statement of Prebid Queries & Clarification

Please confirm bidder's understanding. Also, IA requirement for SG and TG auxiliaries is doubled plus margin for wear and tear as well as leakage margin is added. This shall result in bulky design of service air compressor and increase in capital as well as operating cost of compressed air system. Hence, Bidder requests Owner to remove the margin for wear/tear and leakage.

Owner's Reply

The Provision as per bidding specification shall prevail.

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173

E13

Section / Part / Chapter / Volume Volume III Mechanical Works Chapter - 23 : Compressed Air System

Volume III Mechanical Works Chapter - 23 : Compressed Air System

Clause No. 23.4.8

23.4.8

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

5 of 20 The total Service Air requirement shall be assessed by considering the following guideline: Y = {(2xE+F)+G+H} x [1+ (mw+ml)/100] where Y = Total service air requirement (continuous) E = Service Air requirement (continuous) for SG, TG & auxiliaries of each unit. F = Service Air requirement (continuous) for Water treatment plant and other facilities. F = 2.5 NM3/min (minimum) G= Service Air Requirement for AHP H= Service Air Requirement for CHP mw = Wear & tear margin (10%) ml = Leakage margin (10%) Each Service Air Compressor shall have capacity derived based on above formula or identical to that of each IA compressor whichever is higher While calculating the air requirement of bidder’s equipment/ plant/ systems for continuous requirement of service air, no diversity factor shall be considered and they are assumed to be of “Simultaneous Requirements”. The intermittent requirement of service air, if any, shall be converted into continuous requirement by considering frequency of such requirements or selecting an appropriate diversity factor and such diversity factor shall not be less than 0.6.

Bidder understands that the total Service Air (SA) requirement calculated from the referred clause is for both the units and in order to arrive at the compressor capacity, the same needs to be divided by nos of working SA compressors ( i.e each compressor capacity= Y/2).

5 of 20 (ii) Compressors shall also be sized for the following conditions: (a) Normal Operation of 2 units (b) Normal operation of one units and start-up of second unit (c) Worst condition of starting both units simultaneously.

(ii) Compressors shall also be sized for the following conditions: (a) Normal Operation of 2 units (b) Normal operation of one units and start-up of second unit

Owner's Reply

Please confirm bidder's understanding. Also, SA requirement for SG and TG auxiliaries is doubled plus margin for wear and tear as well as leakage margin is added. This shall result in bulky design of service air compressor and increase in capital as well as operating cost of compressed air system. Hence, Bidder requests Owner to remove the margin for wear/tear and leakage. The Provision as per bidding specification shall prevail.

The Provision as per bidding specification shall prevail.

CRANES & HOIST

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175

Section / Part / Chapter / Volume Volume III Mechanical Works Ch 28 : Cranes & Hoists

Clause No. 28.2.12

Vol-II Ch 5 : General Technical Requirement

7.2.3

Volume III Mechanical Works Ch 33: Plant Layout Requirement

27

Page no.

Bid Specification Stipulation

4 of 15 Hoists and Trolleys with Monorails For items weighing 300 kg and above, hoists and trolleys along with monorails shall be provided throughout the plant where crane cannot be utilized. For items weighing less than 1000 kg, manual hoists can be provided. For items weighing 1000 kg and more, electric hoists (lift & travel) shall be provided. In case the lifting height is more than 10m, electric hoist (lift & travel) shall be provided irrespective of the weight. All 4 of 91 hoists shall be provided with trolleys.

Statement of Prebid Queries & Clarification Discrepancies observed in referred clause. Bidder understands that manual hoist shall be provided for handling of any equipment or any of its part having weight in excess of 500 Kgs. Please confirm bidder's understanding.

Provision as per Clause 28.2.12 shall prevail.

Lifting devices i.e. hoists and chain pulley jacks, etc. shall be provided by the Bidder for handling of any equipment or any of its part having weight in excess of 500 Kgs during erection and maintenance activities. 10 of 15 Provision of Condenser water box handling with crane facilities in Owner to note that alternately electric hoist / any other suitable arrangement case the same are not hinge type, shall be kept. Further adequate shall be provided for handling of condenser water box in case the same is not hinge type. space shall be kept for condenser tube withdrawal. Please confirm.

176

Vol. III/ Ch 28

Owner's Reply

28.2.2

3

In addition, it shall also be possible to handle Generator Stator with tandem operation of two Turbine hall EOT cranes for which necessary arrangements shall be provided. In such case, the combined capacity of two EOT cranes shall not be less than the 110% of weight of Generator Stator, including the weight of lifting beam with swiveling arrangement and slings.

The Provision as per bidding specification shall prevail.

Bidder proposes that the generator stator to be erected & placed on its foundation by strand jack system and not by EOT crane in Tandem Operation. Hence, bidder understand that the cranes shall not be used in tandem for erection and maintenance of generator stator. Further, strand jack arrangement for handling generator stator shall not be part of supply and it will be taken back by bidder once the erection is over.

The Provision as per bidding specification shall prevail.

Owner is requested to confirm.

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Clause No.

Page no.

Bid Specification Stipulation

177

Vol. III/ Ch 28

28.2.2

3

In addition, it shall also be possible to handle Generator Stator with tandem operation of two Turbine hall EOT cranes for which necessary arrangements shall be provided. In such case, the combined capacity of two EOT cranes shall not be less than the 110% of weight of Generator Stator, including the weight of lifting beam with swiveling arrangement and slings.

Vol. III/ Ch 28

28.3 (i) (a)

5

Crane Capacity shall be minimum 310/30 T

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder understands that as per the referred clause No. 28.3 (i) (a), the combined capacity of TG EOT Cranes shall be 620 T, which seems to be extremely on higher side with respect to the actual requirment. Hence, Bidder proposes to consider the safe working load (X) for each TG Hall EOT crane AB bay shall be computed as X = 1.10 x a where a = single heaviest equipment expected to be handled by the crane (excluding generator stator) and accordingly arrive at the TG EOT crane capacity.

Min. Crane capacity shall be 210T/30T.

Owner is requested to accept and confirm same. 178

179

Vol. III/ Ch 28

28.2.3

3

Vol. III/ Ch 28

28.2.10

5

Vol. III/ Ch 28

28.3 (viii) (i)

6

Vol VI/Ch 6

6.02.00

1

Vol VI/Ch 6

6.16.00

7

The main hook capacity of each crane shall be 10% over and above the heaviest component/ equipment to be handled (including lifting beam if applicable and slings etc) or 65 T whichever is higher.

Bidder proposed to consider the safe working load (X) for each TG Hall EOT crane BC bay shall be computed as X = 1.10 x a where a = single heaviest equipment expected to be handled by the crane. Owner is requested to accept and confirm same.

The Provision as per bidding specification shall prevail.

Discrepancy is found in listed clause. Access walkway of minimum 600 mm width with safety handrails shall be provided along the full span length of the CW pump house Both side walkway of minimum 600 mm wide along crane-girder will be crane. provided for TG Hall EOT crane AB bay at EOT crane level. In TG bay at crane rail level, chequered plate walkway of minimum For other EOT cranes, single walkway of minimum 600 mm wide along crane600mm clear width from face of the column to the hand rail on girder will be provided. crane side to be provided for entire A-row & B-row column sectional depth for full length of the building. Owner is requested to confirm. Continuous walkway with GI Hand rail at least 750 mm (Wherever occurs) Confirmed. wide shall be provided along the crane girder level with handrails, on both side of the building. Approach to EOT crane shall be ensured by Cage ladder and staircase. Provisions of safety, health and welfare according to Factories act shall be complied with at design stage. These shall include provision of continuous walkway (minimum 750 mm wide) along crane-girder at crane girder level on both sides of the building, comfortable approach to EOT crane. Cabin, railings, fire escape locker room for workmen, pantry, toilets, rest rooms etc.

E14

ELEVATOR

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Section / Part / Chapter / Volume

Clause No.

Page no.

180

Vol. III/ Ch 29

29.1.2.1

2

181

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

One (1) rack & pinion type stack Elevator of 500 kg (min.) capacity Discrepancy is found in listed clause. complete with all other accessories and associated steel works for Request client to provide Elevator carrying capacity for Chimney to be 275 m high chimney. confirmed.

Owner's Reply

Elevator capacity shall be 500 kg (min.)

Owner is requested to confirm.

Vol. III/ Ch 29

29.2.1.4.1 (i)

3

Carrying capacity (kg) : 400 (minimum)

Vol. III/ Ch 29

29.1.2.6

2

Two (2) 950 kg (one at each end of the turbine building) The specified capacity of passenger elevator does not match as per IS:14665. conventional passenger elevator for Turbine building. This elevator Owner is requested to furnish/clarify the capacity of passenger elevators as shall travel upto Deaerator floor level. per IS:14665.

Vol. III/ Ch 29

29.1.2.7

2

Vol. III/ Ch 29

29.1.2.8

2

1088 kg Elevators shall be provided instead of 950 kg.

Two (2) 950 kg conventional VIP passenger elevators for Service Building. Two (2)- 950 kg conventional passenger elevators, one for each ESP/VFD Control Building.

182

183

E15

Vol. III/ Ch 33

33.4

Volume III : Mechanical Works Chaper – 29: Elevators

29.1.2

Volume III : Mechanical Works Ch 6 : Flue Gas Desulphurisation System

6.1.3

Passenger cum good elevator shall be provided for approach for Bidder understands that Passenger Elevator / Passenger cum Goods Elevator shall be provided as per referred clause Vol. III, Ch. 29, Cl. 29.1.2. steam generator, station building, service building, conference room, coal handling TP in SG area and chimney for O&M. Owner is requested to confirm. The required equipment and services shall be as described below: One (1) rack & pinion type stack Elevator of 500 kg (min.) capacity Two (2) - 3000 kg conventional passenger cum goods elevatorSteam Generator and auxiliaries. Two (2) - 1088 kg conventional passenger elevator- Steam Generator and auxiliaries. Two (2) 950 kg (one at each end of the turbine building) conventional passenger elevator for Turbine building. Two (2) 950 kg conventional VIP passenger elevators for Service Building. Two (2)- 950 kg conventional passenger elevators, one for each ESP/VFD Control Building.

4 of 54 2. Front End Loader 2 To feed limestone from stockpile into feed hopper. 3. Bulldozer 1 For stockpile formation/ management of stockpile in limestone shed/feed limestone from stock pile into feed hopper.

Owner to note that since Dozer for Coal Handling Plant is in Owner scope, hence, bidder understands that bulldozer and front end loader for lime stone plant shall also be in Owner's scope.

Confirmed. Please note that 950 kg shall be read as 1088 kg Elevators.

Confirmed.

Please confirm bidder's understanding.

EFFLUENT TREATMENT PLANT

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Section / Part / Chapter / Volume

184

185

186

187

Clause No.

Page no.

Volume III, Chapter 38

Data sheet, 15.01.04, 15.01.06 & 16.01.07

18 of 19 Chemical measuring / solution preparation tanks - MOC : SS 316. Metering pumps MOC : All wetted parts in SS 316/ Alloy 20

In ETP, material of chemical measuring tank and metering pumps are mentioned as SS 316 and SS 316/ Alloy 20 respectively. Please note that SS 316 is not suitable for acid application. The provision as per We propose polypropylene (PP) / FRP material tanks and metering pumps, bidding specification shall which are more compatible for this chemical dosing application. Request prevail. Owner's acceptance on the same.

Volume III, Chapter 38

38.2.12

6 of 19 The waste water generated will be due to dust suppression and floor cleaning in ash silo area. The waste water will be collected in a sump located in the ash silo area. Pumps shall be installed to transfer the ash rich effluent to ash water sump.

Bidder understands that the waste water shall be transferred to the AHP clarifier for further clarification or disposal due to high suspended solids content.

Volume VII, Mechanical

111-12-3504 EFFLUENT TREATMENT PLANT-Model

Volume III, Chapter 38 38.2.5 4 of 19 & & & Volume VI, Flow Flow diagram Sh 1 of 1 diagram Effluent Effluent treatment plant treatment plant Volume VI, Flow diagram Effluent treatment plant Volume III : Mechanical Works Ch 38 : Effluent Treatment Plant

188

-

Volume II, Chapter 8 & Volume III, Chapter 38

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Please confirm acceptance.

Confirmed.

Turbidity of ETP clarifier reject and the salinity level of RO reject will be higher. Similarly, SSF backwash waste also would have high suspended solids. Hence, it is not advisable to use the waste water in ash water sump which may choke the High pressure water head / jet. Bidder proposes to dispose the same in ash slurry sump. Please confirm acceptance.

Confirmed.

Ash Silo Area Wash Water is transferred to Ash water sump.

The RO reject so generated shall be used in ash disposal. & Flow diagram shows RO reject shall be transferred to ash water sump.

Flow diagram Sh 1 of 1 Flow diagram Effluent treatment plant Effluent treatment plant 38.2.12 6 of 19 ASH SILO AREA WASTE WATER: The waste water generated will be due to dust suppression and floor cleaning in ash silo area. The waste water will be collected in a sump located in the ash silo area. Pumps shall be installed to transfer the ash rich effluent to ash water sump.

Owner's Reply

TG wash, SSF backwash, ESP area waste water, Treated oily water and Boiler waste water will be first taken to CMB/ETP clarifier. After removal of suspended solids and ph correction the same shall be further used into Ash water sump. RO reject water will be disposed to Ash slurry sump for further disposal to Ash pond.

Confirmed.

Please confirm. 5.29.d.2 & Data sheet, 19.01.05

RO permeate - Overall recovery > 80% & Recovery rate 75%

Owner is requested to clarify the discrepancy regarding RO recovery rate as mentioned in clauses of Volume II & III.

Bidding Specification as per Volume-III will prevail.

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Section / Part / Chapter / Volume

Clause No.

189

Volume III, Chapter 38

38.3

Volume VII, Mechanical

111-12-3504 EFFLUENT TREATMENT PLANT-Model

Volume III, Ch 1: SG & Auxiliaries

1.13.10, i)

190

191

Volume III, Ch 1: SG & Auxiliaries

2.21.11, 1)

Volume III, Ch 1: SG & Auxiliaries

1.13.1, x)

Page no.

Bid Specification Stipulation

6 of 19 Equalised waste water from CMB will be treated in pre filteraters. -

Water from CMB is routed for treatment into DMF-UF-RO.

45 of 47 One (01) no. Waste water retaining basin near ammonia unloading & storage system along with 2x100% waste water/ ammonia disposal pumps with motors for transferring drains to Water Treatment Plant (WTP). Chemical dosing system for controlling PH of waste water before sending to WTP.

109 of 120

For neutralization of waste ammonia in waste water retaining basin, chemical dosing system alongwith agitator(s) shall be provided. ..............Sump pump shall be used to supply waste water at PH not more than 8 up to the Water Treatment Plant.

10 of 12 These process drain and oily waste shall be let into the common sump in ETP area (ETP provided by the Purchaser - BOP Bidder).

Statement of Prebid Queries & Clarification

Owner's Reply

Since equalized waste water treatment shall be treated by Dual Media Filter (DMF) - Ultrafiltration (UF) - Reverse Osmosis (RO) as shown in referred flow diagram. Hence, bidder understands that pre filteraters are same as DMF-UF- The provision as per bidding specification shall RO. No other pre filters are envisaged. prevail. Please confirm bidder's understanding. Waste ammonia water will have very high dissolved solids which cannot be sent to water treatment plant. In view of this, Owner is requested to furnish the following for chemical dosing system of ammonia waste treatment system: 1) Type of chemical for dosing 2) Specification 3) Design basis 4) Scheme

The provision as per bidding specification shall prevail.

There is typo error in referred clause. Bidder understands that ETP system is in bidder scope. Confirmed. Please confirm.

192

Volume VI : Civil, Ch 02

30

38.2.7 Ch 38 : Effluent Treatment Plant 193

Ch 38 : Effluent Treatment Plant

3.01.01 a),iii)

Rainfall cum normal run off from coal piles shall be collected by a 4 of 19 drainage system around the coal pile and led by gravity to a coal particle settling basin. 12 of 19 Coal settling ponds effective capacity: 500 ( Each Compartment)

Discrepancy observed in referred clause. Bidder understands that coal settling basin shall be provided for coal area effluent only and no separate tube settler.

38.2.7

Rainfall cum normal run off from coal piles shall be collected by a 4 of 19 drainage system around the coal pile and led by gravity to a coal particle settling basin.

Confirmed. (No separate tube settler).

Please confrim bidder's understanding. Discrepancy observed in referred clause. Bidder understands that coal settling basin effective capacity shall be inline with referred clause no 3.01.01,a), iii) of Vol-II,Ch 38.

Ch 38 : Effluent Treatment Plant

E16

4 of 11 RCC coal settling ponds and tube settler.

Please confrim bidder's understanding.

The provision as per bidding specification shall prevail.. each compartment 500 M3. Rainfall cum normal run off from coal piles will be collected in these compartments.

FIRE DETECTION & PROTECTION SYSTEM

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Section / Part / Chapter / Volume Volume III Mechanical Works Ch 5 : Water Treatment Plant

Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System 195

196

Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System

Clause No. 5.3 j)

24.2

Clause no. 24.4.3

Clause no. 24.4.6 point number (i)

Page no.

Bid Specification Stipulation

3 of 14 Clarified water storage tank of RCC construction of effective capacity of 4 hours requirement in two compartments and a fire water storage tank as per TAC requirement (minimum of 4200 M3) for fire fighting with pump houses to house the following pumps:-

Statement of Prebid Queries & Clarification

Owner's Reply

Owner is requested to clarify the discrepancy regarding capacity of Fire Water Storage Tank.

Min. capacity of Fire storage tank is 4200 M3 shall be followed.

One No. RCC fire water storage tank with suction sump (provided 3 of 70 in /adjacent to Filtered Water Sump). Effective capacity of fire water storage shall be decided based on TAC requirements. However the effective capacity, in any case, shall not be less than 4000 cum with all accessories as specified. Sheet 10 The open conveyors installed shall also be provided with MVW of 70 spray system. It may be noted that full length of each conveyor both top and bottom belt shall be protected with MVW Spray System.

Open conveyor which is installed on Coal yard shall be protected till start of stacker reclaimer movement area and movement area of stacker reclaimer shall not required MVWS system as the same is not feasible, Owner to confirm

Sheet 20 Three (5) nos. of horizontal centrifugal type fire water pumps (3 of 70 Nos for Hydrant+ 2 Nos for Spray System)with drive electrical motors and all other accessories as specified. The quantity and capacity indicated in the specification is only tentative and bidder to work out capacity and quantity based on TAC guidelines / IS 3034.

We understand total Five (5) Nos, fire water pumps (3 Nos for Hydrant+ 2 Nos for Spray System)with drive electrical motors and all other accessories as specified. Owner to confirm

The provision as per bidding specification shall prevail.

Bidder has to optimize as per requirement.

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Section / Part / Chapter / Volume Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System

Clause No.

Page no.

Bid Specification Stipulation

Clause no. Sheet 20 24.4.6 point of 70 number (i), (ii), (iii), (iv), (vi)

198

Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System

DATA SHEET FOR FIRE WATER PUMPS

199

Volume VII-TDMechanical

DWG No. 11112-3601 Flow Diagram fire water pump house and booster pump house

i) Three (5) nos. of horizontal centrifugal type fire water pumps (3 Nos for Hydrant+ 2 Nos for Spray System)with drive electrical motors and all other accessories as specified. The quantity and capacity indicated in the specification is only tentative and bidder to work out capacity and quantity based on TAC guidelines / IS 3034. ii) Three (3) nos. of horizontal centrifugal type fire water pumps driven(2 Nos for Hydrant+ 1 Nos for Spray System)with compression ignition diesel engines along with all accessories required for automatic starting of diesel engine, including fuel oil system, lub oil system etc. The quantity and capacity indicated in the specification is only tentative and bidder to work out capacity and quantity based on TAC guidelines. iii) Two (2) (1W +1S) horizontal centrifugal type fire water jockey with drive motors and all other accessories as per TAC as specified elsewhere. iv) Two (2) nos. of horizontal centrifugal type booster pumps (One motor driven and the other diesel engine driven) for hydrant service for maintaining required pressure on higher elevations of power house and boiler building. v) Two (2) nos. of horizontal centrifugal type booster pumps (One motor driven and the other diesel engine driven) for Spray service for maintaining required pressure on higher elevations of Transfer Points and Mill bay Conveyors. vi) The Selection of Spray Pump Capacity & head shall be designed on the basis of the following criteria whichever is higher Sheet 56 Quantity of the pump specified in the data sheet. of 70

Total Pump Qty specified in the table

Statement of Prebid Queries & Clarification

Owner's Reply

Qty of the pump specified in the data sheet is not matching with the qty of the pump specified in the Cl. No. 24.4.6 & Drawing number 111-12-3601, Owner to please clarify.

The provision as per bidding Specification Clause 24.4.6 shall prevail.

Qty of the pump specified in the data sheet is not matching with the qty of the pump specified in the Cl. No. 24.4.6 & Drawing number 111-12-3601, Owner The provision as per to please clarify. bidding Specification Clause 24.4.6 shall prevail. Qty of the pump specified in the data sheet is not matching with the qty of the pump specified in the Cl. No. 24.4.6 & Drawing number 111-12-3601, Owner to please clarify. The provision as per bidding Specification Clause 24.4.6 shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Volume III 24.4.4.4 Sheet 13 TECHNICAL of 70 Mechanical Works Ch 24 : Fire Detection, REQUIREMENT Alarm :& Protection System

Bid Specification Stipulation The minimum effective capacity of each foam concentrate tank and foam pumps shall be designed considering the following: > Simultaneous protection of any of the fuel oil tank or LDO tanks and operation of two hydrants for 60 minutes. or > Minimum capacity if specified elsewhere. > A design margin of at least 10% shall be considered over the calculated foam concentrate capacity, tank capacity and discharge capacity of the foam discharge pumps.

Statement of Prebid Queries & Clarification We are considering 100% foam concentrate tank as per the principle of fire case that is, one largest capacity tank internal fire protection on the common dike area and operation of 2 hydrants, along with that additionally 10 % margin will be included for selecting actual capacity of 100% foam concentrate tank. Duration of fire protection for tank internal protection will be 60 minutes and Duration of usage for fixed Hydrant will be used only for 30 minutes operation. The design philosophy is followed as per NFPA 2011. Portable foam monitor shall have its individual foam tank. Please confirm.

Owner's Reply

The provision as per bidding specification shall prevail.

201

Volume III 24.4.3 DESIGN Sheet 10 f) In cable galleries the water spray shall cover the exposed area We understand "Cable galleries" shall be read as "Coal Conveyor", owner Mechanical Works PHILOSOPHY of 70 (f) of both the forward and return conveyors and idlers. In transfer to confirm. Ch 24 : Fire Detection, FOR SPRAY points, crusher house, track hopper, pent house etc thewater spray Alarm SYSTEM shall cover the drive equipment, pulleys, chutes, other equipments & Protection System of the floor and at various elevations. Specifically in Transfer Agreed. Points, crusher house and all the areas where Floor protection is required, total floor area is to be considered in calculating water requirement, not just the equipment coming on that floor.

202

Volume III Mechanical Works Ch 24 : Fire Detection, Alarm & Protection System

24.4.2 A

4 of 70 xxvi) Administrative building

Bidder understands that the Administrative Building is not envisaged for this project. Hence the tap off for the hydrant line shall be provided at the plant boundary. The other systems to be provided for fire detection and protection system for Administrative Building beyond plant boundary for shall be in Owner's scope of work.

Include the FDPS package for Admin. Building also.

Please confirm. E17

HVAC

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Section / Part / Chapter / Volume Volume III Mechanical Works Chapter 11 : Air Conditioning System

Clause No. 11.1.1

Page no.

Bid Specification Stipulation

2 of 30 TG Building area and ESP control Buildings 1 x 100% capacity steam powered Vapour Absorption Machines (VAM) as working and 2 x 50% capacity Vapour compression screw / centrifugal chilling units as standby shall be provided for TG building mainly consisting Central control areas etc. Central control area shall mainly consisting of Control Rooms, Control Equipment Rooms, Telecommunication Rooms, Microprocessor, Computer and Programmers Rooms, Static Excitation Control room, Data Storage Rooms, UPS Rooms, Instrumentation Laboratory and Steam & Water Analysis Room, Conference Room, Shift In-Charge Engineer's Room, AVR Room etc.

Volume III Mechanical Works Chapter 11 : Air Conditioning System 11.3.35

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder shall provide separate systems for TG Building & ESP Building. The system provided for TG Building shall be in line with the referred clause. However for ESP Building, 2 x 100% (1W+1S) duty Water cooled DX system with Vapour compression screw compressor shall be provided. Please confirm acceptance. The provision as per bidding specification shall prevail.

8 of 30 (TG building area including Central control building & ESP Control Buildings & Service building shall be air conditioned using central chilled water system as specified elsewhere).

204

Volume III Mechanical Works Chapter 11 : Air Conditioning System

11.3.32

7 of 30 For calculating friction loss in piping system: SHALLIAM & HAZEN Due to typo error, the same shall be read as follows: For calculating friction loss in piping system: WILLIAM & HAZEN formula formula shall be used with C value as 100. shall be used with C value as 100.

Agreed.

Please confirm. 205

Volume III Mechanical Works Chapter 11 : Air Conditioning System

11.5.8

19 of 30 Non- Chemical Type Scale Preventer The unit should be a non-chemical on-line type scale preventer not requiring any chemicals. Non-chemical water treatment system should prevent the formation of hard scale in cooling circuits of air conditioning equipment. It should work with a combination of Adsorption, and Turbulence. The inner core should be able to convert the hardness salts into colloidal particles. The unit should not require any electricity or any other source of energy. The unit should not have any recurring, operating and maintenance cost. The size of the unit shall be determined based on the water quality and water flow rate. The unit shall be installed in the condenser water circuit. The outer casing should be of stainless steel. The method of checking the performance of system through computer simulation shall be provided

Since Clarified water is provided for makeup, scale preventer is not required. Please confirm. However, if the scale preventer treatment has to be provided, Owner to allow alternative treatment such as softening plant. The provision as per bidding specification shall prevail.

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207

Section / Part / Chapter / Volume Volume III Mechanical Works Chapter 12 : Ventilation System

Clause No. 12.4.1.1

Chapter 11 / Volume III 11.1.2

11.3.35

208

209

Chapter 11 / Volume III 11.3.1

Chapter 11 / Volume III 11.3.4 and 11.3.5

Page no.

Bid Specification Stipulation

6 of 16 Numbers of Air washer units each of maximum capacity 1,00,000 m3/hr, with all accessories, DIDW centrifugal fans, circulating water pumps etc. shall be provided. Each air washer unit (evaporative system) shall consist of the various sections such as Air Washer chamber/ casing, tank, distribution plates, set of metallic/ fabric filters at suction, suction louvers, bird screens, water headers, spray nozzle, piping, valves etc, drift eliminators, pumps fans, necessary controls & instrumentation and all other required accessories. 2 of 30

FGD control building 2 x 100% (1W+1S) duty Water cooled DX system with Vapour compression screw compressor shall be provided for FGD control building.

8 of 30

iii. Estimated heat load range of 7.6 TR to 30 TR:Air cooled type Precision packaged AC plant with hermetic scroll compressors.

sheet 5 of 30

0 Ambient Dry bulb temperature: 46.6 C.

sheet 5 of 30

11.3.4. A minimum design margin of 10 % shall be considered while sizing AC Plant and related equipment. Solar load, all internal loads due to equipment, lighting, fresh air, occupants etc. shall be considered while calculating the heat load. 11.3.5. Margins for calculating heat load: i. 12.5%, 10% & 10% margins on sensible heat, latent heat & overall heat respectively is to be considered while calculating heat load.

Statement of Prebid Queries & Clarification

Owner's Reply

Owner is requested to provide the quantity of Air Washer Units to be considered for each Unit. Shall be decided during detail engg stage in line with specification requirement.

For FGD Control Building : Bidder will choose Air cooled Packaged AC units when load is below 30 TR. Please confirm our understanding.

Since Owner has not provided summer, monsoon and winter design weather data, Hence Bidder will consider Weather data as following, Summer DBT=40.7oC Summer WBT=23.4oC Monsoon DBT=33.9oC Monsoon WBT =29oC Winter DBT=8oC Winter WBT=7.6oC Above data is for Patna, as per ISHRAE Weather data. Please confirm our understanding. Bidder understanding is overall 12.5%, 10% & 10% margins on sensible heat, latent heat & overall heat respectively is to be considered and with derived capacity AC units shall be selected. Also additional 10% margin is not considered for equipment selection as already 12.5% and 10% margin is considered in sensible and latent load in cooling load calculation. Please confirm our understanding.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail for Ambient DBT. For other parameters, climatological of "Dehri" may be referred to. Reffer ammendement -04

The provision as per bidding specification shall prevail.

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Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

210

Chapter 11 / Volume III 11.3.35

sheet 8 of 30

Air condition system type selection criteria: iv. Estimated heat load up to 7.5 TR:Hi-wall-Split Air conditioners.

For Office / Non plant areas Load up to 15 TR : Hi-wall-Split Air conditioners. Please confirm acceptance.

211

Chapter 11 / Volume III 11.3.35

sheet 8 of 30

Air condition system type selection criteria: ii. Estimated heat load range of 30 TR to 60 TR:Water cooled type condensing units (D-X type) plant with hermetic or semi-hermetic Screw/scroll compressors iii. Estimated heat load range of 7.6 TR to 30 TR:Air cooled type Precision packaged AC plant with hermetic scroll compressors.

For load range 15 TR to 60 TR : AC system shall be with Air cooled DX type Packaged AC units. Please confirm acceptance.

Redundancy of Equipments

Redundancy of AC units for Office / Non-plant areas : no Standby AC units Please confirm acceptance.

Owner's Reply The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

212

Chapter 11 / Volume III 11.3.36

sheet 9 of 30

213

Chapter 11 / Volume III 11.10.1

sheet 26 1) Supply & Return air duct of AC system: of 30 Resin bonded glass wool or closed cell elastomeric Nitrile rubber : 50mm Thick

Incase Bidder select elastomeric Nitrile Rubber then we consider thickness to The provision as per be 25 mm which is technically equivalent to 50mm thick glass wool. bidding specification shall Please confirm acceptance. prevail.

214

Chapter 12 / Volume III 12.1.3

sheet 2 of 16

Bidder has considered the following:

The areas to be ventilated by Mechanical ventilation process (using supply air fans and/or exhaust fans / roof extractors) shall consist of but not limited to the following:

Compressor area, Switchgear/MCC Rooms, GIS Hall, Security, Time office, gate house shall be Positive pressurized with Pre filtered supply air, tube a) All the pump houses like Fuel oil pump house, CW pump house, axial fan and Pressure Relief Damper (PRD) for exhaust air. Clarified water pump house, Fire water pump house, Raw water AC plant areas, Pump House, Non AC SWAS areas, Workshop, store, intake Canteen, Bunker bay, Transfer tower, Lube oil purification room, Battery pump house, Raw Water pump house, Fire Water Booster Pump room, toilets, kitchens, pantry, WTP areas, chemical areas, Labs, fuel oil house, Ash water and Ash Slurry pump house, etc. area, shall be Negative pressurized in room with wall/roof mounted exhaust b) Battery rooms, lube oil purification room, non A/C areas of fans and fresh air through wall mounted louver. SWAS room. .......................................................................................... m) All non-AC areas of service building. n) Any other areas which are not covered either by air conditioning system or by evaporative cooling system.

215

Chapter 12 / Volume III 12.2.3

sheet 3 of 16

Inside dry bulb temperature shall be minimum 50 C below the design ambient dry Bulb temperature during summer for evaporative cooled areas.

The provision as per bidding specification shall prevail.. Further detailing shall be done during detail engg stage.

Inside dry bulb temperature shall be minimum 30 C below the design ambient The provision as per dry Bulb temperature during summer for bidding specification shall evaporative cooled areas. prevail. Please confirm acceptance.

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Section / Part / Chapter / Volume

Clause No.

Chapter 12 / Volume III 12.2.14

Page no. sheet 4 of 16

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Supply air fans, exhaust air fans & ventilation of each area shall be For small areas like pantry, toilet (where rooms are ventilated by propeller provided with local starter panels. fans) separate local starter panels are not required. Please confirm the acceptance.

Owner's Reply Agreed for toilet & Pantry only.

217

Chapter 12 / Volume III 12.4.7.2.3

sheet 10 For switchgear and cable vault rooms other than in TG building, of 16 the supply air shall be filtered and distributed through air distribution system by means of Centrifugal fans, ducting & grills.

For Cable vault rooms other than in TG building, the supply air shall be filtered and distributed through air distribution system by means of Tube Axial The provision as per bidding specification shall fans, ducting & grills as per standard industry practice. prevail. Please confirm acceptance.

218

Chapter 11 : Air Conditioning System

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Since this is being an EPC project, the steam for VAM shall be in bidder's scope.

11.4, iii.

Steam for Vapour absorption system (VAM) shall be provided by the purchaser at one point.

Confirmed Please confirm. E18 219

GAS CYLINDER Volume III Mechanical Works Ch 3 : Gas Cylinders

3.2.1

2 of 4

4 of 4 220

Volume III Mechanical Works Ch 3 : Gas Cylinders

3.2.1

3 of 4

4 of 4 221

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Volume III 3.1.1 Mechanical Works Ch 3 : Gas Cylinders MILL REJECT HANDLING SYSTEM Vol-III/Ch:20 Mill 20.2,d) Reject Handling System

2 of 4

2 of 7

The no. of hydrogen cylinders required for (2x660) MW units shall be computed as above or 400, whichever is higher.

S.No. Description H2 Gas Cyl CO2 Gas Cyl 1. No. of Cylinders 200 50 (Minimum) The no. of Carbon dioxide cylinders shall be computed as above Owner is requested to clarify the discrepancy regarding quantity of Carbon Dioxide Cylinders. or 100 whichever is higher. S.No. Description H2 Gas Cyl CO2 Gas Cyl 1. No. of Cylinders 200 50 (Minimum) The Nitrogen gas shall be used for nitrogen capping of boiler parts, Owner is requested to clarify whether Nitrogen Cylinders have to be regenerative heaters etc. considered for Ammonia System which shall be used for SCR.

One (1) Mill Reject vessel below each pyrite hopper with pneumatically operated inlet/outlet valves Mill reject vessel shall be provided with one pneumatic cylinder operated inlet valve (material handling valve), outlet valve

223

Vol-III/Ch:20 Mill Reject Handling System

20.2.2

4 of 7

20.2.1

3 of 7

Owner is requested to clarify the discrepancy regarding quantity of Hydrogen Cylinders.

The conveying velocity of reject shall not be more than 6.0 m/sec and number of cycles shall not be more than 6 per hour.

Hydrogen Cylinders shall be 400 Nos.

CO2 Cylinder shall be 100 Nos.

Shall be considered.

As mill reject conveying is batch conveying process, pneumatic type isolation valve at outlet of mill reject conveying vessel is not envisaged as per MRHS OEM proven practice. The provision as per bidding specification shall Request owner to relook the referred tender clauses and confirm bidder's prevail. understanding. Bidder envisage that Mill Reject conveying velocity is governed by MRHS OEM proven engineering practice. Same will be provided to owner during The provision as per bidding specification shall detail engineering for owner's approval. prevail. Owner is requested to confirm bidder's understanding.

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225

Section / Part / Chapter / Volume

Clause No.

Vol-III/Ch:20 Mill Reject Handling System

20.2.4

Vol-III/Ch:20 Mill Reject Handling System

20.2

Page no. 5 of 7

7 of 7

20.2.4

5 of 7

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Air Compressors Bidder understand entire plant air compressor chapter can not be followed for For technical requirements of screw compressors refer Chapter 23: MRHS conveying air compressors (3 Nos.) as these compressors shall be Compressed Air System, Volume III. selected considering the MRHS OEM required process parameters (after cooler etc. not required for MRHS). Hence, Vol-III/Ch:23 Compressed Air System can not be followed for MRHS conveying air compressors. In view of this request, owner to please provide MRHS specific compressor datasheet for MRHS handling system. Bidder understands that for mill reject system compressor, auxiliary cooling DATA SHEET FOR MILL REJECT HANDLING SYSTEM 5.0 Air Compressor water (secondary circuit) can also be used as per compressor vendor recommendations. c Cooling : Water Cooled (DMCW) Please confirm acceptance. Air Compressors For technical requirements of screw compressors refer Chapter 23: Compressed Air System, Volume III.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

226

Vol-III/Ch:20 Mill Reject Handling System

20.2

7 of 7

DATA SHEET FOR MILL REJECT HANDLING SYSTEM 6.0, c) Material of Bags suitable for: suitable for prolonged operational temperature of 300 deg. C.

As per mill manufacturer/OEMs recommendation, mill reject temperature varies between 140 Deg C to 160 Deg C. Hence, Bidder envisage 160 Deg The provision as per C as filter bag material. bidding specification shall prevail. Request owner to relook and confirm acceptance.

227

Vol-III/Ch:20 Mill Reject Handling System

20.2, f)

2 of 7

f) Each silo shall have an effective storage capacity of sixteen (16) hours considering each mill in the bay rejecting @ 2.0% of mill capacity

Due to discrepancy, mill reject generation shall be considered as 1% of mill capacity corresponding to unit operation at 100 % BMCR with worst coal firing. Effective storage capacity of each mill reject silo to be considered accordingly.

20.2

6 of 7

DATA SHEET FOR MILL REJECT HANDLING SYSTEM: d) Rate of Rejects Generated per mill: 2.0% of mill capacity or maximum actual whichever is higher

1.7 (ii) d)

39 of 47

Mill rejects storage silos (2) no. for each unit in steel construction each having an effective storage capacity of sixteen (16) hours considering the number of mills connected to each silo and rejecting @ of 1% of mill capacity for the worst coal conditions/ or maximum actual, whichever higher. Necessary supporting steel structure, platforms, staircase, manual operated unloading gate, 3 mm thick SS plate liners covering straight length portion and conical portion of mill reject storage hoppers (bunkers), level switches, air relief devices, etc. shall also be provided.

20.2.1

3 of 7

...Number of cycles shall not be more than 6 per hour.

Volume III Mechanical Works Ch 1: SG & Auxiliaries Section 1 : Scope

228

Vol-III/Ch:20 Mill Reject Handling System

Please confirm acceptance. 2% of Mill capacity.The provision as per bidding specification shall prevail.

Bidder understand that the numbers of cycle mentioned in this clause is No. of Cycles - 6 per applicable for each mill. Owner is requested to confirm bidder's hr/stream understanding.

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Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

229

Vol-III/Ch:20 Mill Reject Handling System

-

-

-

230

Volume III : Mechanical Works Ch 20 : Mill Reject Handling System

20.2 g)

3 of 7

g) The storage silo shall be designed to provide a clear access of 5 Discrepancy observed in referred clauses for clear access below MRHS silo. m for trucks to come under the silo and receive the rejects using suitable chute work. Bidder understands that storage silos shall be designed to provide a clear access of 4.5 m for a Road Tanker/Trucks to come under the silo in line with clause 1.7, d) of Vol-III, Ch-1, SG & Auxiliaries. The storage silos shall be designed to provide a clear access of 4.5 m for a Road Tanker/Trucks to come under the silo & receive Owner is requested to confirm bidder's understanding. the rejects using suitable chute work.

Owner's Reply

Bidder may consider drag chain conveyor system for Mill Reject Handling System as an alternative to pneumatic system due to its distinct advantages The provision as per in power consumption and O&M cost point of view. Please confirm bidding specification shall prevail. acceptance.

5 M clear access shall be provided.

Volume III, Ch 1: SG & 1.7, (d) Auxiliaries Section 1 : Scope

39 of 47

231

Volume III : Mechanical Works Ch 20 : Mill Reject Handling System

20.2 j)

3 of 7

j) Three (3) (1W/unit + 1S) oil free screw compressors, with drives & accessories, to cater to the conveying air requirements of mill reject handling system. Compressors shall be located in Compressor House of Ash Handling System.

Bidder understands that this project being a turnkey contract, bidder understands that MRHS compressor can be located in main plant air The provision as per compressor house also based on layout requirement. bidding specification shall prevail. Please confirm acceptance.

232

Volume III : Mechanical Works Ch 20 : Mill Reject Handling System

4.0

6 of 7

MILL REJECT SILO

Bidder understands that liners are required at the conical portion of the mill reject silo only and not in vertical straight length. Hence, liner are at vertical straight length is not envisaged.

b Construction Steel Construction (MS IS 2062)with 3mm Thk SS 304 lining in conical as well as vertical portion

Owner is requested to confirm acceptance. E20 233

CCW SYSTEM Volume III : Mechanical Works Ch 16 : DMCW System

16.7.4.2

5 of 12

Suitable cleaning system complete with all equipment and accessories (viz. pumps, piping, valves etc.) for inside cleaning of the PHE’s.

Liner is required for 1 M of vertical portion.

Owner to note that bidder has never come across of such cleaning/flushing requirement of PHE in executed projects and none of the PHE suppliers are aware of such requirement. In view of above and clarified water, bidder has not considered the separate cleaning/flushing of PHE.

Confirmed.

Please confirm. In case, the same is to be provided, bidder requests Owner to furnish the specification, P&ID and design philosophy.

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Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

234

Vol-III/Ch 16 : DMCW System

13., a)

10 of 12

DATA SHEET FOR DMCW PUMPS: Material of Construction: Casing: AASTM A 351 CF8M

As the DMCW circuit utilizes passivated DM water which is non-corrosive, Bidder envisage to consider Cast iron IS 210 FG 260 as the material of The provision as per bidding specification shall construction for casing. prevail. Request owner to confirm acceptance.

235

Vol-III/Ch 16 : DMCW System

16.3

3 of 12

Bidder shall ensure that the average temperature rise of DMCW is limited to 5.5 deg.C under all circumstances.

There is no technical merit to limit the DMCW temperature rise to 5.5 Deg.c. Please note that DMCW system is closed cooling system without any interface with customer design system viz. complete system design rest with EPC bidder. Further the various coolers of turbine, generator, BFP, CEP etc. have varying temperature rises. Accordingly the overall temperature rise of DMCW system may exceed 5.5 Deg C.

Vol-III/Ch 16 : DMCW System

16.7.5.4,A), c )

c ) The pressure drop across each operating plate heat exchanger shall be limited to eight (8.0) MWC in the DMCW circuit and eight (8.0) MWC in the ACW circuit.

Bidder envisage to consider maximum allowable pressure drop through PHE shall be at design flow of CCW and ACW system. The Heat Exchanger shall be capable of passing a flow of at least 1.1 times the design flow rate on The provision as per both DMCW and ACW sides, however pressure drop across PHE shall be bidding specification shall increased accordingly. prevail. Request owner to relook and confirm acceptance.

236

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16.7.5.4,A), f ) 16.6

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f) Each Plate Type Heat Exchanger shall be capable of passing a flow of at least 1.1 times the design flow rate on both DMCW and ACW sides without exceeding the pressure drop values indicated previously in cl. 16.7.5.4 (A) (c). The capacity of the make up tank shall be adequate to provide a minimum of one (1) hour make-up water storage capacity in between the minimum and maximum operating levels based on the make up demand.

The provision as per bidding specification shall prevail.Average temperature = 5.5oC

As the DMCW system is closed system, there is no consumption of water in the system. There will be minor leakage in the system which is considered as 2 m3/hr as per tender plant water balance diagram dwg. No. 111-12-3100. Agreed. Hence, the capacity of make up tank is considered as 10 m3. Request owner to confirm bidder's understanding.

238

239

111-12-3201

-

-

Flow diagram of equipment cooling water system: Pump recirculation line

Vol-III/Ch 16 : DMCW System

16.13.8

9 of 12

A control valve shall be provided to maintain a constant pressure differential between the main supply and return headers of DM water (primary circuit of ECW system of unit auxiliaries)

111-12-3100

-

-

Composite Water Scheme: DMCW pump is receiving cold water at suction side from PHE.

111-12-3201

flow dia. Of equipment cooling water system: DMCW pump is receiving HOT water at suction side from equipment cooler.

Bidder envisage to provide CCW recirculation line with control valve for header pressure control. Request owner to confirm bidder's understanding.

Agreed.

There is a discrepancy for DMCW pump suction water (i.e. Hot water suction vs. Cold water suction) as per referred clauses. Hence, bidder understand that DMCW pump is receiving HOT water at suction side from equipment cooler. as shown in flow dia. Of equipment cooling water system(111-12-3201). Bidder understand that CCW scheme as Confirmed. shown in composite water scheme is tentative. Request owner to confirm bidder's understanding.

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Section / Part / Chapter / Volume

240

111-12-3201

E21 241

GENERAL Volume II General & Schedules Ch 1 : Intent of Specification

242

243

Volume I BID DATA SHEETS (BDS)

Volume II General & Schedules Ch 4 : Provenness

Clause No. -

Page no. -

1.0

5.0

Bid Specification Stipulation Flow diagram of equipment cooling water system:

Statement of Prebid Queries & Clarification

Please furnish flow diagram of CCW system for SG auxiliaries and BOP system as the same is not found in flow dia. Of equipment cooling water Drawing is available. system(111-12-3201).

5 of 12 Bidders shall note that one (1) more unit of 660 MW may be added in future by the EMPLOYER as an expansion unit for possible augmentation of the station. For this purpose, the employer envisages suitable space provision to be kept for one (1) 660 MW future expansion unit to be integrated along with that of the present two (2) nos. 660 MW units, which are shown in the indicative Plot Plan (Refer Volume - VII). As such suitable provision shall be kept by the bidder in various Civil, Mechanical, Electrical and C&I systems of present 2x660 MW units for future augmentation/integration & interconnection of corresponding system & facilities with the present units as brought out in various subsections/ parts/chapters of the technical specification (Volume II to VII).

Bidder has observed discrepancies in tender specification and P&ID/Flow Diagrams for provisions to be kept for future unit . Hence, Owner is requested to clearly define the provisions to be kept for future expansion unit both in specification as well as in P&IS/Flow diagrams to remove discrepancies /contradiction.

45 of 63 5.0 Major Inputs from Employer:

Bidder understands that Ammonia and Limestone shall be provided by Owner.

(Month from NOA) Unit#1 Unit#2 …….................................................................................................. 2. Availability of Fuel Oil for SG 35 41 3. Availability of coal* 39 45

Owner's Reply

Please confirm.

The provision as per bidding specification shall prevail.

S. No. Input

4.5

8 of 40 4.5 Fire Detection and Protection System: The bidder/its sub-vendor should have designed, supplied, erected and commissioned atleast two (2) numbers of Fire protection Systems, each of contract value not less than INR 35.0 million or equivalent in foreign currency (exchange rate applicable as on date of Technocommercial bid opening), in thermal power plant installations.

Please confirm.

Confirmed.

Owner is requested to amend the proveness criteria for Fire Detection and Protection System as follows:The bidder/its sub-vendor should have designed, supplied, erected and The provision as per commissioned atleast two (2) numbers of Fire protection Systems, each of contract value not less than INR 35.0 million or equivalent in foreign currency bidding specification shall (exchange rate applicable as on date of Techno-commercial bid opening), in prevail. thermal power plant / industrial installations.

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245

246

Section / Part / Chapter / Volume Volume II General & Schedules Ch 4 : Provenness

Volume II General & Schedules Ch 4 : Provenness

Volume II General & Schedules Ch 4 : Provenness

Clause No. 4.18.2

4.18

4.19

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

13 of 40 Ash handling system The Bidder/ its Sub- vendor who is a supplier of ash handling systems but does not meet the requirements under clause 4.18.1 in part or in full can also participate provided it has executed at least the following systems of ash handling plant involving design, engineering, manufacture, supply, erection and commissioning: a) Bottom ash handling system comprising of jet pump system in conjunction with water impounded Bottom Ash Hopper. b) Fly Ash Handling System for conveying fly ash from ESPs in dry form (involving pneumatic conveying systems of vacuum or pressure type) or in wet (slurry) form. The systems mentioned at 4.18.2 (a) and (b) above should have been in successful operation in at least two (2) plants for two (2) years prior to the date of Techno-Commercial bid opening and should have been installed for pulverized coal fired boiler units generating not less than 40 TPH of ash per boiler.

Bidder requests to modify referred clause as follows in line with all recent NTPC tenders: "The systems mentioned at 4.18.2 (a) and (b) above should have been in successful operation in at least one (1) plant for two (2) years prior to the date of Techno- Commercial bid opening and should have been installed for pulverized coal fired boiler units generating not less than 40 TPH of ash per boiler."

13 of 40 Ash handling system The systems mentioned at 4.18.1(a), (b) & (c) above should have been in successful operation in at least two (2) plants for at least two (2) years prior to date of Techno-Commercial bid opening. For the purpose of qualification, the experience as at (a), (b), (c) & (d) above in separate plants also is permissible.

Owner to note that the clause No. 4.18.1 (d) is not found in the referred Chapter of Volume II.

14 of 40 Coal Handling Plant 4.19.1 The Bidder/its Sub-vendor should have designed, manufactured/got manufactured, erected and commissioned at least two (2) integrated bulk material handling plants (essentially comprising of conveying and crushing) including all associated structural steel works and electrical works of minimum 1500 Metric tonnes per hour rated capacity or above for coal or other minerals of equivalent volumetric capacity which should have been in successful operation for at least two (2) years prior to the date of Techno- Commercial bid opening. At least one (1) tripper should have been supplied and commissioned in the above bulk material handling plants.

Bidder requests to modify referred clause as follows in line with all recent NTPC tenders: "The Bidder/ its Sub- vendor should have designed, manufactured/ got manufactured, erected and commissioned at least one number integrated bulk material handling plant (essentially comprising of conveying and crushing) including all associated structural steel works and electrical works of 1000 Metric tonnes per hour rated capacity or above for coal or other minerals of equivalent volumetric capacity which should have been in successful operation for at least one (1) year prior to the date of Techno-Commercial bid opening."

Owner's Reply

The provision as per bidding specification shall prevail.

Please clarify the same.

(d) to be deleted.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

247

Volume II General & Schedules Ch 4 : Provenness

4.19.5

248

Volume III : Mechanical Works Chaper-31 : Weigh Bridge

31.2

Volume II Ch 8 : Functional Guarantee & Liquidated Damages

3.10.2, f)

249

250

Volume II Ch 8 : Functional Guarantee & Liquidated Damages

Page no.

Bid Specification Stipulation

15 of 40 Wagon Tippler The Bidder/its Sub-vendor shall source crescent wagon tipplers from a manufacturer/supplier who has supplied minimum two (2) crescent wagon tippler suitable for tippling Indian Railway Wagons used for transportation of coal or other minerals which should have been in successful operation for at least two (2) years prior to the date of Techno-Commercial bid opening. 2 of 5

One (1) Electronic road weigh bridge of 60 Tonnes capacity suitable for weighing loaded road trucks/trailers shall be provided. The system shall have an accuracy of +0.25% of actual weight. The scope shall include supply of PC, printer, UPS with 1 hour backup, software capable of providing details like net weight, tare weight, total weight etc. Stamping by relevant authorities shall also be included in Contractor’s scope of work.

26 of 78 Coal Handling plant: Total power consumption for all the equipments including auxiliaries with single stream operation at its guaranteed flow path capacity except:- Lighting - Hoists - Coal sampling unit - Sump Pumps - Elevators - DS, DE, Ventilation, SW System, Potable water system Duty factor for coal handling plant shall be 0.5

3.10.1, (xiii)

21 of 78 COLTCS

3.10.1, (viii)

20 of 78 Main turbine Condenser tube cleaning system pumps.

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder requests to modify referred clause as follows in line with all recent NTPC tenders: "The Bidder/its Sub-vendor shall source crescent wagon tipplers from a manufacturer/supplier who has supplied minimum two (2) one (1) crescent The provision as per wagon tippler suitable for tippling Indian Railway Wagons used for bidding specification shall transportation of coal or other minerals which should have been in successful prevail. operation for at least two (2) years prior to the date of Techno-Commercial bid opening". Owner to mention the purpose of the referred 60 T weigh bridge along with its location.

Location will be decided during detailed engineering. Please include 60 T Weigh Bridge as per spec.

Being an EPC project, Owner is requested to mention the longest flow path of coal handling plant for which auxiliary power consumption to be guaranteed.

The provision as per bidding specification shall prevail.

Bidder has observed that there is repeatation of COTCS for main turbine under guaranteed aux power list. Bidder understands that either of referred clause for COLTCS shall be considered.

Confirmed.

Please confirm bidder's understanding.

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Section / Part / Chapter / Volume Volume II Ch 8 : Functional Guarantee & Liquidated Damages

Clause No. 3.10.2, b)

Page no.

Bid Specification Stipulation

24 of 78 Air Conditioning System: Power consumption at motor input terminals of working units (i.e. excluding stand-by) at its rated duty point of Chilling machines, Chilled water Pumps, Condenser water Pumps, Air/water cooled condensing machines, precision air conditioners, Air handling units (AHU) fans, cooling towers, for the Air conditioning system.

Statement of Prebid Queries & Clarification Bidder proposes to consider the Air Conditioning loads for the following in line with prevalent industry practice: Power consumption at motor input terminals of working units (i.e. excluding stand-by) at its rated duty point of Chilling machines, Chilled water Pumps, Condenser water Pumps, Air handling unit (AHU) fans, for the Air conditioning system of TG building, Service Building, FGD control room, ESP control room.

Owner's Reply

Confirmed.

Please confirm acceptance. 252

253

E22

Volume II Ch 8 : Functional Guarantee & Liquidated Damages

3.10.2, c),x.)

Volume II Ch 8 : Functional Guarantee & Liquidated Damages

3.10.2, d, 6

25 of 78 x.) Jockey Pumps for firefighting system xv.) Sludge transfer pumps in PT Plant, Centrifuge and thickened sludge transfer pumps xvi.) Pumps (for ETP system, zero discharge system) 25 of 78 Ash Handling Plant: i) Conveying air compressors

Bidder proposes that referred pumps shall not be considered for aux power guaranteed as the same pumps are not working continuously. Confirmed. Please confirm acceptance. Bidder understands that conveying compressor and transport air compressor are same. Confirmed. Please confirm.

MANDATORY SPARES

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255

256

Section / Part / Chapter / Volume Volume II General & Schedules Ch 1 : Intent of Specification

Volume II General & Schedules Ch 9 : Mandatory Spares Volume II General & Schedules Ch 9 : Mandatory Spares

Clause No. 1.0

G.0

Page no.

Bid Specification Stipulation

2 of 12 Scope of Work The brief scope of the work comprises of the design, engineering, manufacture, assembly, testing at manufacturer's works, packaging into properly sized units and shipping & marine insurance, custom clearance, port clearance & handling, satisfactory reconciliation with the custom authorities, inland transport, inland insurance, right from Ex-works / Ex-show room / Port of Entry up to completion of trial operation, delivery to site, receipt, unloading, handling and storage at site, watch & ward, fabrication at site, erection, testing, supervision, precommissioning, and commissioning, performance & guarantee performance testing and putting into successful operation to the satisfaction of the EMPLOYER of the complete coal fired thermal power station consisting the following below listed system but not limited to the system, equipment and associated works as detailed in the accompanied Specification including supply of mandatory spares, special tools & tackles and three (03) years operation and maintenance spares for “Buxar Thermal Power Project (2x660 MW)” on the basis of single point responsibility, completely covering the following activities and services in respect of Steam Generator, Steam Turbine Generator, all Balance of Plant (BoP) systems all electrical systems including switchyard, complete control and instrumentation and complete Civil, structural and A hit t lTippler k & Accessories ifi d ( t f R il Sidi /T k) 39 of 106 G.0 Wagon 1.3 Hydraulic Pump with electric motor

19.00 2.17

21

E23 257

LAYOUT Volume VI, Chapter 6.0 6.17.00 (3)

258

Volume III

set of each type & size

, coupling, valves & servo motor (mounted on pump) etc. 61 of 106 POWER CYCLE PIPING: 17 of 106 Piping A. Power Cycle Piping

Statement of Prebid Queries & Clarification Owner to note that the bidder shall provide only Mandatory spares in line with the Mandatory spares list provided with the tender specificaiton. No separate Operation & Maintenance Spares shall be provide. Please confirm acceptance.

The provision as per bidding specification shall prevail.

Owner to note that the quantity of spares to be provided in the referred clause is not specified. The same has been considered as "One (1)" in absence of data.

Tender Drawing 12 of 16 (34)

Water Intake well shall generally………wet pit pumps of required capacity, switchgear room,….. Flow Diagram Raw Water Intake System

Agreed.

Please confirm. Owner to note that the spares for Power Cycle Piping are mentioned in all the three referred clauses. Please specify the clause to be followed for Power Cycle Piping related spares to be provided for this project.

32 of 106 Power Cycle Piping

8 of 9

Owner's Reply

Alternatively, Switchgear room may be constructed on the bank of the river. Please confirm. Not received. Request client to provide the same.

To be decided during detailed engineering

Confirmed. Refer addendum-01 for route plan from intake to plant boundary.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Volume II, Chapter 1.0 1.2

6 of 12

Plant water Intake & Supply system - Raw water reservoir (5days)

Volume III, Chapter 5.0 5.1

2 of 14

…….in plant Raw Water Reservoir of 6 days storage approx. 530,000cum.

Volume VI, Chapter 2.0 2.6 (22)

3 of 11

Statement of Prebid Queries & Clarification Discrepancy between various clauses. Bidder understands that the capacity of the Raw water reservoir to be considered is 530,000cum. Owner to confirm.

The capacity of raw water reservoir-530,000 M3.

Raw water reservoir of required storage capacity (Minimum 6days storage) for running of 2x660MW unit.

260

Volume VII, Tender Drawings Mech Layouts

Plot Plan

111-290200

Raw water reservoir cap - 530,000cum

Volume III, Chapter 33.0

33.4 (31.)

10 of 15

I. Trestle height in outlying area shall be 5.0 M (BOS)

6.05.00

2 of 09

Cable & Pipe Rack (except at road and rail crossing) : 3000 mm

Volume VI, Chapter 6.0

261

262

263

Volume III, Chapter 21.0

Plot Plan Volume VII, Tender Drawings Mech Layouts Volume III, Chapter 24 Sl. No. 1.0

Volume VI, Chapter 11.0 Volume VII, Tender Drawings Mech

Discrepancy between various clauses. Tresle/Piperack height (except for raod and rail crossing) shall be 3000mm. Please confirm.

21.2.3 - a & b

11.14

3 of 52

111-290200 69 of 70

13 of 16

Flow Diagram 111-11LDO Unloading 1300 system

Owner's Reply

Two (2) Rotary type Ash Conditioners for …………during loading Discrepancy in Tender specification and Plot Plan. of ash to open trucks. Fly Ash transport mechanism (By Road or Rail) to be clarified by client. Two (2) Telescopic spouts arrangement with scavenger fan……for unloading of fly as to closed tankers. In Plot Plan FA silos are marked over the railway track and no road access marked.

5 M shall be considered.

FA Transportation by road and rail shall be considered.

Dry Chemical Powder type : Chlorination building near Raw water Intake pump house

Chlorination building for Raw water Intake system is not envisaged. Please confirm.

Unloading pump houses to unload oil from road tankers or rail wagons……..

We understand that fuel oil shall be transported thru road tanker only and not rail wagons. Please confirm. Confirmed.

In Flow Diagram LDO Handling System it has mentioned of 10 oil tankers terminal Railway oil terminal not considered.

Agreed.

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265

Section / Part / Chapter / Volume Volume VI, Chapter 11.0

Volume III, Chapter 24.0

Clause No. 11.15.1

Page no. 14 of 16

Volume III, Chapter 24.0

268

……The above capacity shall be generated partially by excavating The permitted maximum water level of reservoir is not clear. the area to a specified bottom level of the reservoir and partially by Bidder understands that the water levels for reservoir can be optimized and the formation of embankment with CI/CL type of soil…… suitably deceided by the Bidder satisfying the functional requirements. Please confirm. Free board of 500mm minimum shall be maintained. The maximum level of the reservoir will be kept at level which will be at least 500mm below the finished floor level of the plant or just at the plant formation level.

03 of 70

One no. RCC fire water storage tank with suction sump (provided in/adjacent to Filter Water Sump)

5.3

2 of 14

Clarified water storage tank of RCC construction of effective capacity of 4hours requirement in two compartments and a fire water storage tank as per tac requirement (minimum of 4200 cum)

24.1

02 of 70

The fire pumps shall be installed in the Clarified water pump house. Bidder understands that Clarified water pump house and Fire water pump house shall be single common facility.

2.6

4 of 11

33. Fire water reservoir, fire water pump house and fire station. 34. Clarified Filter water reservoir & pump house.

Please confirm.

2 of 15

v. Clarified water Pump house (Underslung Crane) xiv. Fire Water Pump House (Overhead EOT Crane)

Bidder understands that Clarified water pump house and Fire water pump house shall be single common facility (Vol. III, Ch.24, Cl. No. 24.1). The same shall be provided with underslung crane. Please confirm. Sump gates shall be operated by separate electric hoist instead of pump house overhead crane. Owner to confirm

Volume VI, Chapter 02

267

Statement of Prebid Queries & Clarification

24.2

Volume III, Chapter 5 Volume VII, Tender Drawings 266

Bid Specification Stipulation

Volume III, Chapter 28 28.1.3

Volume III, Chapter 15 15.3 (j, k)

15.4.10 (viii)

3 of 49

j) EOT crane for handling pumps, motors and other equipment in the CW pump house….. k) Electric Hoist for handling stoplog gates and coarse screens.

6 of 49

Viii) …….Sump gates shall be accessible by the pump house overhead crane.

Bidder understand one no. covered RCC storage tank with 2 (two) equal compartments for catering clarified & fire water pumps with dedicated water storage for fire water pumps shall be provided. Please confirm.

Owner's Reply

Free board shall be minimum 1.5 M

RCC storage with 2 compartments for clarified water and another compartment for fire water of 4200 M3 capacity shall be considered.

Confirmed.

Confirmed.

Confirmed.

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270

271

Section / Part / Chapter / Volume Volume III, Chapter 4

Clause No. 4.1

Page no. 2 of 3

Bid Specification Stipulation ……………..The distance from raw water intake structure to raw water reservoir shall be asumed as 9000M.

Statement of Prebid Queries & Clarification Discrepancy between various clauses. Client to provide the inputs for Raw water Intake location and route study to workout the distance.

Volume VI, Chapter 06 6.17.00 (1)

8 of 9

……...Pipe line route about 6.00 km in length passes through/under Agricultural Land, Barren Land………

Volume III, Chapter 15 24.4.2 (A) (xiv)

4 of 70

Hydrant system protects the following building/facilities…… Raw Water Intake Pump House.

Raw water Intake Pump House is outside plant boundary and hence Hydrant network not envisaged for the same. Please confirm.

The cable vaultspace/cable spreader room below the HT/LT switchgear rooms, Control Rooms, unit control equipment room, Programmer room, UPS, Charger & Battery Rooms, Boiler MCC room shall have 800 mm wide and 2.1 m high movement passage all around the cable trays in the cable vault/ cable spreader room...

It is not practical to have clear height of 2.1 m in the cable spreader room below HT/LT switchgear rooms in TG building. Clearances / Space shall be provided to th eextent feasible as per industry practise and acceptable norms.

Volume III, Chapter 33 33.3.5

5 of 15

Owner's Reply

The distance between Raw water intake to plant boundary is 6 KM.

Confirmed.

Confirmed. Bidder to clarify what is acceptable norms.

Please confirm. 272

273

Volume III, Chapter 33 33.4 (11)

Volume VII, Tender Drawings Mech Layouts

8 of 15

11. Clear approach width between Boiler & ESP (Height=8M) 12m minimum

Bidder understands that the 12m indicated is interdistance between column centre line of Boiler last column and ESP first column.

Plot Plan

111-29- -0200

33.4, 19)

Coal Mills shall be located either on the side of the boiler or on rear Front mill arrangement i.e. between turbine building & boiler is widely 9 of 15 side of the boiler i.e. between boiler and ESP. accepted practice throughout the world & also accepted by NTPC & SEBs.

Volume III/ Chapter 33

The provision as per bidding specification shall prevail.

Bidder understands mill arrangement shown in Plot Plan is indicative and alternate mill arrangements (Front or rear) can also be proposed by Bidder. The provision as per bidding specification shall prevail.

Owner is requested to accept front mill arrangement as an alternative. Please confirm. 274

275

Volume VII, Tender Drawings Mech Layouts

Plot Plan

Volume VII, Tender Drawings Mech Layouts

Plot Plan

111-290200 --

Width of road mentioned in Plot Plan is indicative. Bidder proposes to fix the same considering single/double lane road based on the functional requirement. Please confirm Bidder understands that Unit numbering defined for BTG block is indicative only, same can renumbered keeping provision for future.

111-290200 --

Please confirm.

Width of road already shown in Plot Plan shall be adhered to. The provision as per bidding specification shall prevail.

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277

Section / Part / Chapter / Volume

Clause No.

Page no.

Volume VII, Tender Drawings Mech Layouts

Plot Plan

111-290200

Volume VII, Tender Drawings Mech Layouts

Plot Plan

Bid Specification Stipulation

--

111-290200 --

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder understands arrangement/orientation of coal stock pile and associated facilities for CHP shown in Plot Plan are indicative only , same can be The provision as per rearranged/reoriented based considering space allocated within railway bidding specification shall siding. prevail. Please confirm. Bidder understands 1. layout of transformers shown in transformer yard is indicative only, same can be relocated considering functional requirement and location of switchgear room. 2. layout of CW supply and return line is indicative, same can be rerouted based on the optimized path satisfying functional requirement.

1) Confirmed. 2) The provision as per bidding specification shall prevail.

Please confirm. 278

Volume VII, Tender Drawings Mech Layouts

TG Building Floor Plan

111-210300

--

Bidder understands that 1. the pitching of BTG block is indicative, same can be changed/adjusted by Bidder based on the functional requirements. 2. the location and size of common switchgear room shown in layout drawing is indicative. Bidder shall be allowed to relocate / resize the same. 3. the equipmet layout shown in various floors of power house building is indicative only, same can be relocated based on the function requirement. 4. Power house building width AB & BC bay width is indicative, same can be resized based on Bidder's proposed layout and requirement. 5. Length of Power house building and Grid interspacing is indicative, same can be resized based on layout requirement. 6. the pipe cum cable rack shown in CD bay is indicative only. Inorder to have better and through accessibility for vehicular movement bidder shall be allowed to rearrange the pipe rack supported by TG building or Boiler column. Please confirm.

1) Pitching shown is minimum. 2,3) Confirmed.

4) Width shown is minimum (to be followed by bidders). 5) Length shown is minimum with 9 bays. Grid interspecing may be revised 6) Confirmed.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Volume VII, Tender Drawings Mech Layouts

TG Building Floor Plan

Volume III, Ch 28

28.2.2

111-210200 / 111-210300 / 111-210400 / 111-210600

Volume III, Ch 33

33.4 (1)

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

There is disconnect between Tender clauses and Tender drawings. Client is requested to provide clarity on the design requirement of TG EOT crane. Client to confirm if the TG building main EOT crane is required to be designed for tandem operation to handle the Generator Stator. Also no of In addition, it shall also be possible to handle Generator Stator with maintenence bays requried to be clarified accordingly. tandem operation of two Turbine hall EOT cranes for which necessary arrangements shall be provided. In such case, the combined capacity of two EOT cranes shall not be less than the 110% of weight of Generator 3 of 15 Stator, including the weight of lifting beam with swivelling arrangement and slings.

Owner's Reply

Two nos. of unloading bays (Grid1-2 and 11-12) are indicated in TG building layout drawing.

1. Drawing shall be followed for number of bays. 2. TG building main EOT Crane is required to be designed for tandem operation to handle Generator Stator.

Minimum Three (3) nos. of Maintenance bays in TG building shall be provided.... 280

281

282

Volume VII, Tender Drawings Mech Layouts

TG Building Floor Plan

Volume VII, Tender Drawings Mech Layouts

TG Building Floor Plan at 24.0 M and 37.5 M EL

Volume VII, Tender Drawings Mech Layouts

Cross Section

7 of 15 111-210200 / 111-210300 / 111-210400 / 111-210600 111-210400

Bidder understands location and number of interconnecting platform are indicative only. same shall be arranged based on the functional requirement and floor level corresponding to power house building and boiler floor level. --

--

Confirmed.

Bidder understands that CD bay framing for Critical pipe supports indicated is tentative. The same shall be based on the critical piping layout and pipe stress analysis requriements, therefore bidder shall be allowed to rearrange Confirmed. the same. Please confirm Bidder understands number of floor and elevation of floors in BC bay shown is indicative only. Bidder does not envisage any floor requirement above Deaerator.

111-210600 --

Various floor elevation and extent shall be rearranged based on the equipment layout and functional requirement.

Confirmed.

Please confirm. 283

Volume VII, Tender Drawings Mech Layouts

Cross Section

111-210600 --

Bidder understands roof height and top of girder (T.O.G.) elevation (30.0M) shown for AB bay hall is indicative only. Same shall be rearranged based on the functional requirement considering EOT and its handling requirement of major equipment. Please confirm.

T.O.G elevation is indicative. Shall be finalized during detailed engineering.

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Section / Part / Chapter / Volume

Clause No.

E24 284

CW & ACW system Volume III, Chapter 15 15.3.q & 15.4.10.ix

285

Volume III, Chapter 15 15.4.5 & 16 &

286

Volume III, Chapter 15 15.4.4

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

4 & 7 of 49

Separate bays for unloading and maintenance purposes.

Bidder proposes to provide common bay adequate for unloading & maintenance. Request Owner's confirmation on this proposal.

5 of 49 & 3 of 12 & 11 of 12

The design flow rate in the clarified water (ACW) side of the operating PHEs for the unit shall be considered same as the design DMCW flow rate, with the average temperature rise of ACW system limited to 5.5 deg. C under all circumstances. & In computing the design heat load and design DMCW flow in individual DMCW system Bidder shall ensure that the average temperature rise of DMCW is limited to 5.5 deg.C under all circumstances. & Inlet/Outlet water temperature : Bidder to work out. However DMCW / ACW system temperature rise not to exceed 5.5 deg. C.

Design flowrate and Temperature rise of DMCW system need not to be same as that of ACW system. Further, hot water temperature of ACW will be selected such that not to exceed the CW return water temperature at condenser outlet, as selected /optimized by bidder, instead of restricting ACW side temperature rise to 5.5°C. Hence, ACW and DMCW design flowrate and temperature rise shall be optimized by Bidder. Confirmed.

5 of 49

The provision as per bidding specification shall prevail.

Owner is requested to confirm.

A minimum of 10% margin on frictional losses assuming C=100 on Bidder will consider 10% margin on friction loss calculated for piping, valves Hazen William’s formula for design purposes based on respective & fittings. No margin will be considered on equipment static pressure drop pumping capacity as obtained above. e.g. condenser pressure drop or PHE pressure drop etc.

Confirmed.

Please confirm. 287

Volume III, Chapter 15 15.4.10

288

Volume III, Chapter 15 & Volume VI, Flow diagram CW & ACW system

15.5.3 & Flow diagram CW & ACW system

6 of 49

The pump house shall accommodate five (5) CW pumps and three Bidder may opt for separate pump house and forebay channel for CW and (3) ACW pumps. ACW pumps.

8 of 49 & Sh 1 of 1

An interlock shall trip all running CW pumps from very low level of water in the sump of the CWPH. To achieve the above interlock, there shall be three (3) level switches, which shall operate on two (2) out of three (3) logic. Two (2) other level switches shall also be provided which shall generate alarm in case of low level in the sump.

Please confirm. There is a discrepancy in the type and number of level instruments specified for CW pump house sumps. In Volume III write-up, total five (5) nos. of level switches are specified for control of CW & ACW pumps, whereas the flow diagram shows four (4) nos. of level transmitters at each sump. Owner is requested to provide the actual instrument requirements for the system.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 15 15.6.A.c

Page no. 9 of 49

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

The selected head of CW pump shall provide for adequate margin Bidder understands that equipment design flow means condenser design so that pumps are capable of supplying equipment design flow at flow and not the pump design/rated flow. 47.5 Hz frequency of power supply. In other words, at 47.5 Hz, CW pumps should be capable to meet flow and head requirement corresponding to 100% TMCR condition.

Owner's Reply

Confirmed.

Please confirm bidder's understanding. 290

Volume III, Chapter 15 15.6.A.e

9 of 49

Bidder requests Owner to consider single floor CW pump house arrangement The pump & motor assembly shall be supported by two (2) floor arrangement. The lower floor will be provided below the discharge . The same is a proven industry practice & is widely accepted by major clients The provision as per like NTPC etc. flange to provide an access to the discharge connections. The bidding specification shall discharge head prevail. shall have a flanged discharge connection.

291

Volume III, Chapter 15 15.6.C.f

11 of 49

The pump suction bell diameter shall be such as to limit the flow velocity at the maximum flow to within 1.5 m/sec.

The pump suction bell diameter shall be selected as per velocity mentioned in HIS 9.8 standard. Confirmed. Owner is requested to confirm.

292

Volume III, Chapter 15 15.6.C.j & Annexure-1, 2.02.19

12 of 49

Continuous motor rating (at 50 deg C ambient) for CW and ACW pumps shall be fifteen percent (15) above the demand at duty point or ten percent (10%) above the maximum load demand of the driven equipment in the complete operating range (including run out condition of pump and shut off condition in case pumps are envisaged to be started with the discharge valve closed) whichever is higher to take care of the system frequency variation. & Continuous motor rating (at 50 deg C ambient) for pump shall be at least ten percent (10%) above the maximum load demand of the driven equipment in the complete operating range including runout condition of the pump and shut off condition in case pumps are envisaged to be started with the discharge valve closed) to take care of the system frequency variation.

There is a contradiction in various clauses of specification regarding the motor rating of CW pumps. Hence, Bidder will select continuous motor ratings (at 50 deg C) for all types of pumps at 10% above the maximum load demand of the driven equipment under entire operating range to take care of Continuous motor rating (at 50 deg C ambient) for voltage and frequency variation. CW and ACW pumps shall Please confirm Bidder's consideration. be fifteen percent (15) above the demand at duty point or ten percent (10%) above the maximum load demand of the driven equipment in the complete operating range (including run out condition of pump and shut off condition in case pumps are envisaged to be started with the discharge valve closed) whichever is higher to take care of the system frequency variation.

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Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 15 15.10.B.a

Page no. 18 of 49

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

For the offered pump, bidder should have carried out the model Alternatively, CW pump model test shall be done as per HIS, which is being test. Bidder shall furnish the above test results along with the widely accepted in the industry. tender. The model test should have been conducted as per Japanese standard JIS-BOwner is requested to confirm the proposal. 8327 (latest version) and specific speed of the model tested should lie within ± 5% of the specific speed of the pump offered.

Owner's Reply

Confirmed.

294

Volume III, Chapter 15 15.10.C

19 of 49

(a) At twice the prototype maximum Froude number, i.e., the Froude number of the model is two times that of the prototype. (b) At equal velocity criterion, i.e., the velocity is same both in the model and prototype.

Sump model study will be carried out as per Froude's law of similitude as per specification and additional two conditions as specified in Cl. No. 15.10 C.) The provision as per (a) & (b) are not required. Owner is requested to confirm. bidding specification shall prevail.

295

Volume III, Chapter 15 Data sheet

34 of 49

ACW Pumps - Voltage level : 11 kV

Voltage lever for ACW pumps shall be as per Electrical specification based on kW rating.

296

Volume III, Chapter 15.0

15.17

Please confirm. 32 of 49 Circulating water (CW) pipework …… shall be rolled from minimum Since CW pipe shall be provided with concrete encasement, the thickness of 22 mm thick carbon steel plates to IS 2062. CW pipe works shall be based on AWWA standard considering all the cases like internal pressure, buckling, buoyancy, external loading etc. Bidder shall arrive at final thickness after due calcualtions for the same.

Confirmed. The provision as per bidding specification shall prevail. Shall be 22 mm (min.) thickness rolled from IS:2062 carbon steel plates. Concrete encasement not envisaged.

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298

Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 15.0

15.4.4

Chapter 2.0

3.3.1

Volume III/ Chapter 15 5

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

5 of 49 The required cooling water flow for the CW system shall be worked There is contradictiong in the stated clauses of tender specification. Owner is out by the Bidder considering the maximum possible thermal load requested to confirm the clause to be considered for CW system design and condition encountered in condenser and CW temperature rise. The to keep all Bidders at par. design CW flow shall be computed by the bidder considering a minimum of five (5) % margin (i.e. 5% margin over and above the required CW flow) as computed out above and shall be substantiated by the Bidder after conducting optimization studies. 30 of 70 Design circulating water quantity at inlet temperature of 33 degC 82000m3/hr

36 of 49

DATA SHEET FOR BUTTERFLY VALVES : ACW pump discharge, CT blowdown and other applications as per flow diagram

Owner's Reply The required cooling water flow for the CW system shall be worked out by the Bidder considering the maximum possible thermal load condition encountered in condenser and CW temperature rise. The design CW flow shall be computed by the bidder considering a minimum of five (5) % margin (i.e. 5% margin over and above the required CW flow) as computed out above and shall be substantiated by the Bidder after conducting optimization studies.

The butterfly valve opening / closing time shall be decided during detail engineering based on transient analysis. Please confirm.

Confirmed.

Valve opening /closing time : Maximum 40 seconds 299

Volume III/ Chapter 27 27.8.3

11 of 35

For miter bend of large dia pipe (450 nb and above) bend radius of 1 times For pipe size 250 NB and above mitre bends may be used for all pipes except rubber lined pipes. The bend radius shall be 1½ times the nominal diameter shall be allowed by fulfilling pressure drop requirement. the nominal pipe diameter. 90 deg. Bends (mitre) shall be in 5 pieces (4 cuts) and 45 deg. mitre bends shall be in 3 pieces 22½ deg. Fabrication Confirmed. of mitre bends shall be as detailed in BS 2633/BS534.

300

Volume III/ Chapter 27 27.3.5 4)

6 of 35

Galvanized material to be used for instrument air only and not for plant air. Material of Construction for Instrument and Plant air : ASTM A-53 type E Gr. B galvanized/IS 1239 heavy galvanized/IS 3589 Gr 410 Galvanized to IS-4736 or equivalent. Owner is requested to confirm.

E25

Power Cycle Piping, Valves, Fittings & Thermal Insulation

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 26

26.2 Note i)

302

Volume III, Chapter 26

26.4

303

Volume III, Chapter 26

26.8 (vii)

Page no.

Bid Specification Stipulation

4 of 26 If ASTM A335 P92 is offered/ used by the bidder/ contractor for piping (pipes, fittings, components, valves, etc.), maximum allowable stress values to be considered for all design calculation of piping (pipe, fittings, components, valve etc.) will be reduced by 10% w.r.t allowable stress value indicated in code case (ASME-B31.1) for P-92. Similarly, if any proven material equivalent to ASTMA-335-P92 is used, the maximum allowable stress to be considered for all design calculation of piping (pipe, fittings, components, valve etc.) will be reduced by 10% w.r.t allowable stress value indicated in the standard/code of that equivalent material.

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder proposes to use full allowable stresses as per ASME B31.1 Code Case for ASTM A 335 Grade P92 material, since the material has been used across the industry and is already proven in terms of manufacturing, testing, fabrication, etc. The provision as per bidding specification shall prevail.

The provision as per As per standard practice, head room of not less than 2.2m above the walkway/ working area shall be made available. Request to accept the same. bidding specification shall prevail. 12 of 26 ….. and surface finish of 16 RMS or better in area of stem packing. Surface finish in area of stem packing shall be as per Valve manufacturer's The provision as per standard practice. bidding specification shall 5 of 26 The pipe routing shall be such that a clear head room of not less than 2.5 m above the walkway /working area is available.

prevail. 304

Volume III/ Chapter 27 5.5.1

50 of 70

The HP heaters (1x100% or 2x50% strings) shall be of horizontal and U-tube type with integral desuperheating, condensing and drain cooling sections.

In case bidder offers 2X50% HP heater train, option of 3 way valves for HP heater bypass shall be allowed as an alternative against motorized bypass valves.

Flow Diagram - Feed water system DWG no. 111-11-0700

The same is widely accepted by NTPC & SEBs.

Volume VII

The provision as per bidding specification shall prevail.

Owner to confirm. E26 305

LP Piping, Valves, & Specialities Volume III, Chapter 27 Volume III, Chapter 27

27.3.5

6 of 35 Fuel Oil Piping - API 5L

27.5.3

8 of 35 …. Vertical clearance of 2.5 M above walkways and working areas As per standard practice,vertical clearance not less that 2.2m above the The provision as per …. walkway/ working area shall be made available. Request to accept the same. bidding specification shall prevail.

Volume III, Chapter 27

27.14.2

18 of 35 …. gun metal to IS:318 for sizes 50 NB and below.

308

Volume III, Chapter 27

27.24.1

28 of 35 Strainer Element - Stainless Steel (AISI 316)

Bidder propose Strainer Element - Stainless Steel (AISI 304)

309

Volume III, Chapter 27

27.24.2

28 of 35 Strainer Element - Stainless Steel (AISI 316)

Bidder propose Strainer Element - Stainless Steel (AISI 304)

306

307

Bidder requests to allow ASTM A 106 Gr B for Fuel Oil Piping.

Bidder proposes forged carbon steel valves in place of gun metal valves for sizes 50 NB and below. Request to approve the same.

Confirmed.

Confirmed. The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

310

Volume III, Chapter 27

27.24.1

28 of 35 The free area of the strainer element shall be at least (6) six times the internal area of the connecting pipe.

The free area of the strainer element shall be at least (4) four times the internal area of the connecting pipe as per the standard practice of manufacturers.

311

Volume III, Chapter 27

27.24.2

28 of 35 The free area of the strainer element shall be at least (6) six times the internal area of the connecting pipe.

The free area of the strainer element shall be at least (4) four times the internal area of the connecting pipe as per the standard practice of manufacturers.

Owner's Reply The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

312

Volume III, Chapter 27 27.1..3

2 of 35

WILLIAM & HAZEN formula shall be used for calculating the friction loss in piping systems with the following “C” value….. Stainless steel pipe 100

As stainless steel pipes are highly resistant to corrosion, the surface finish of the pipe internal surface is maintained and hence, "C" value of stainless steel The provision as per pipes shall be considered as 140 instead of 100 as given in specification. bidding specification shall This is being followed in other executed projects as well. prevail. Request Owner's confirmation in this regard.

313

Volume III, Chapter 27 27.1..6

3 of 35

Corrosion allowance of 1.6 mm will be added to the calculated thickness being considered.

Bidder understands corrosion allowance is applicable only for carbon steel pipes. The same is not applicable for stainless steel and alloy piping. This practice is being followed across many executed projects installed across the Confirmed. globe. Please accept our above proposal.

314

Volume III, Chapter 27 27.3.5

6 of 35

Dematerialized water, (condenser Make up water, Boiler fill and Deaerator Fill water) & DMCW overhead tank make-up water : Stainless steel to ASTM A-312, Gr. 304 welded for sizes above 50mm NB & Stainless steel to ASTM A312, Gr. 304 sch. 40 Seamless for sizes 50 mm and below

Alternatively, rubber lined carbon steel pipe material shall also be used for DM water application, which is also compatible with the medium. Request Owner to accept our proposal.

F

Electrical

1

Vol.I / SCHEDULE 10 8A _____ _____ 10 Vol.I / SCHEDULE - 8B

22 of 31 Generator Circuit Breaker _____ 23 of 32

Bidder would like to clarify that GCB is not applicable to this project, hence the referred clause shall be considered as deleted. Owner may please confirm.

Vol.I / SCHEDULE 11 8A _____ 11 _____ Vol.I / SCHEDULE - 8B

23 of 31 VFD system for condensate transfer pump motor _____ 24 of 32

Bidder would like clarify that VFD is not applicable to Condensate Transfer Pump and hence request Owner to delete the referred clause. Owner may please issue amendment.

Vol.I / SCHEDULE 22 8A _____ _____ 22 Vol.I / SCHEDULE - 8B

31 of 31 Bidder to add all other Type Test as required in the Tender Bidder request Owner to list out all applicable type test to keep all bidders at _____ Document & Quote their takeout price. If not quoted, Bidder will be par. 31 of 32 liable to conduct the Type test without any cost implication to the Owner.

2

3

The provision as per bidding specification shall prevail.

Agreed.

Agreed. VFD is not applicable.

The provision as per bidding document shall prevail

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

4

Vo.II/Chapter-1: Intent of Specification

-

4 of 12 Following works will be excluded from the bidder’s scope: e) Construction of Substation for Construction Power (33/11 kV Substation already constructed by Owner)

Bidder request Owner to indicate coordinates of point from which Construction Power needs to be drawn and location of Purchaser’s 33/11 kV sub-station on the plot plan.

5

Vol.II / Ch-4 Provenness

5.0

28 of 40 PROVENNESS CRITERIA FOR ELECTRICAL EQUIPMENTS

The provenness requirement has no relevance with the bid opening date and The provision as per bidding hence such requirement should be deleted from various clause of document shall prevail provenness criteria for electrical equipement.

6

Vol.II / Ch-4 Provenness _____ Vol.II / Ch-4 Provenness

5.1.1 _____ 5.1.2 (i)

7

Vol.II / Ch-4 Provenness

5.2.1

… … successful operation for a period of at least two (2) years prior to the date of Techno-Commercial bid opening. … ... 28 of 40 Bidder / Sub Vendor should have designed, manufactured, for a _____ period of not less than two (2) years prior to the date of Techno29 of 40 Commercial bid opening. _____ Bidder / Sub Vendor should have designed, manufactured, … … … have been in successful operation for a period of not less than two (2) years prior to the date of Techno-Commercial bid opening.

29 of 40 POWER TRANSFORMERS (Generator transformer, Station transformer/ Stand-by/start up transformer (as applicable), Unit transformer) Bidder / Sub Vendor should have designed, manufactured, installed / supervised installation and commissioned/supervised commissioning of at least two (2) nos. (one each at two different installations) of 400 KV or above class Generator transformers of at least 200 MVA capacity (either three phase transformer as a single unit or single phase transformer) which should be in successful operation for at least two(2) years prior to the date of Techno-Commercial bid opening.

Refer 73 in Plot Plan for location of construction power.

The provenness requirement has no relevance with the bid opening date and hence such requirement should be deleted from referred clause. Apdated clause shall be read as: "Bidder / Sub Vendor should have designed, manufactured, for a period of not less than two (2) years. prior to the date of Techno-Commercial bid The provision as per bidding opening. document shall prevail _____ Bidder / Sub Vendor should have designed, manufactured, … … … have been in successful operation for a period of not less than two (2) years. prior to the date of Techno-Commercial bid opening.. " Bidder understands that this clause is applicable to Power Transformers and not only for Generator Transformer, Hence bidder request to amend the referred clause as below: "Bidder / sub vendor should have designed manufactured, installed / supervised installation and commissioned / supervised commissioning of at least two (2) nos (one each at two different installations) of 400KV or above class Generator Power Transformers of at least 200MVA capacity (either three phase transformer as a single unit or single phase transformer) which should be in successful operation for at least two (2) years. prior to the date of techno commercial bid opening . "

The provision as per bidding document shall prevail

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Section / Part / Chapter / Volume Vol.II / Ch-4 Provenness

Clause No. 5.2.1

Page no.

Bid Specification Stipulation

29 of 40 POWER TRANSFORMERS (Generator transformer, Station transformer/ Stand-by/start up transformer (as applicable), Unit transformer) Bidder / Sub Vendor should have designed, manufactured, installed / supervised installation and commissioned/supervised commissioning of at least two (2) nos. (one each at two different installations) of 400 KV ... ....

9

Vol.II / Ch-4 Provenness _____ Vol.II / Ch-4 Provenness

5.2.1 _____ 5.2.2

29 of 40 Bidder / Sub Vendor should have designed, manufactured, _____ installed … … … ... operation 29 of 40 for at least two(2) years prior to the date of Techno-Commercial bid opening. _____ ... ... ... which are in successful operation for two (2) years prior to the date of Techno-Commercial bid opening and have established manufacturing facilities ... ... ...

Statement of Prebid Queries & Clarification

Owner's Reply

Transformer manufacturing industry classify themselves based on Voltage/MVA class. Manufacturers for Higher Voltage/MVA class and lower Voltage/MVA class are different. Since, the rating of UT is comparatively lower (voltage class (20-27 kV) & MVA (30-40 MVA)) than other power transformers like GT/ST, the large power transformer manufacturers are reluctant to manufacture UT. Hence, bidder request to take out Unit Transformer from this clause.

The provision as per bidding document shall prevail

The provenness requirement has no relevance with the bid opening date and hence such requirement should be deleted from referred clause. Updated clause shall be read as: "Bidder / Sub Vendor should have designed, manufactured, installed … … … ... operation for at least two(2) years . Prior to the date of Techno-Commercial bid The provision as per bidding opening . document shall prevail

_____ ... ... ... which are in successful operation for two (2) years prior to the date of Techno-Commercial bid opening and have established manufacturing facilities ... ... ..." 10

Vol.II / Ch-4 Provenness

5.3.1

29 of 40 Bidder / Sub-vendor should have designed, manufactured, … … … … atleast two (2) different nstallations for atleast two (2) years prior to the date of Techno-Commercial bid opening. _____ ... ... ... which are in successful operation for two (2) years prior to the date of Techno-Commercial bid opening and have established manufacturing facilities... ... ...

The provenness requirement has no relevance with the bid opening date and hence such requirement should be deleted from referred clause. Updated clause shall be read as: "Bidder / Sub-vendor should have designed, manufactured, … … … … atleast two (2) different nstallations for atleast two (2) years. prior to the date The provision as per bidding of Techno-Commercial bid opening. document shall prevail _____ ... ... ... which are in successful operation for two (2) years prior to the date of Techno-Commercial bid opening and have established manufacturing facilities... ... ..."

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

11

Vol.II / Ch-4 Provenness

5.2.2

29 of 40 Bidder/Sub Vendor who have designed, manufactured,………. ………. In case of award, the Associate or Collaborator of the. This Deed of Joint Undertaking should be submitted prior to the placement of order on approved Sub Vendor.Bidder / Sub Vendor (as applicable) will be required to furnish an on-demand Bank Guarantee for INR 22 Million (Indian Rupees Twenty Two Million only).

The provenness requirement has no relevance with Bank Guarantee and hence such requirement should be deleted from referred clause. Updated clause shall be read as: "Bidder/Sub Vendor who have designed, manufactured,………. ………. In case of award, the Associate or Collaborator of the. This Deed of Joint The provision as per bidding Undertaking should be submitted prior to the placement of order on approved document shall prevail Sub Vendor.Bidder / Sub Vendor (as applicable) will be required to furnish an on-demand Bank Guarantee for INR 22 Million (Indian Rupees Twenty Two Million only)."

12

Vol.II / Ch-4 Provenness

5.4.1

30 of 40 Bidder / Sub Vendor should have manufactured & supplied … … … which should have been in successful operation for a period of at least two (2) years prior to the date of Techno-Commercial bid opening.

The provenness requirement has no relevance with the bid opening date and hence such requirement should be deleted from referred clause. Updated clause shall be read as: The provision as per bidding "Bidder / Sub Vendor should have manufactured & supplied … … … which document shall prevail should have been in successful operation for a period of at least two (2) years prior to the date of Techno-Commercial bid opening ."

13

Vol.II/Chapter-4 Provenness

5.15.1

35 of 40 The Bidder/Sub vendor should have designed, manufactured, erected, tested and commissioned one (1) Gas Insulated Switchgear (GIS) equipment(s) installation having at least six (6) bays of 400kV or above voltage class with short circuit current of not less than 40 kA for 1 second, which should have been in successful operation for minimum two (2) years prior to the date of Techno-Commercial bid opening.

GIS manufacturer supplies GIS bays and do supervision of Erection and commissioning of GIS at site. Hence, the referred clause need to be modified as below: "The Bidder/Sub vendor should have designed, manufactured, erected/ supervised erection, tested/ supervised testing and commissioned/ The provision as per bidding supervised commissioning of one (1) Gas Insulated Switchgear (GIS) document shall prevail equipment(s) installation having at least six (6) bays of 400kV or above voltage class with short circuit current of not less than 40 kA for 1 second, which should have been in successful operation for minimum two (2) years. prior to the date of Techno-Commercial bid opening"

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Section / Part / Chapter / Volume Vol.III: Mechanical Works / Chapter 33: Plant Layout Requirement

Clause No. 33.4

Page no.

Bid Specification Stipulation

Page 11 A walkway of 600mm (minimum width) with pipe hand rails & toe of 45 guards shall be provided all along length of the trestle for maintenance of cables & pipes.

Statement of Prebid Queries & Clarification Pipe hand rails & toe guard for the same may be avoided all along the length of the gallery where walkway is between the verticle cable trays. Owner may please confirm.

Further, bidder request to provide specification of the walkway in the Cable trestle.

15

16

17

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.02.08

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.02.09

1.02.09

Owner's Reply

IN CHP AREA ALL CABLES (EXCEPT FOR SAFETY SWITCHES, ILLUMINATION & RECEPTACLES) SHALL NOT BE ROUTED INSIDE THE CONVEYOR GALLERY. WALKWAY TO BE PROVIDED FOR ACCESS TO CABLES IN PIPE RACK/ CABLE RACK / TRESTLE. MECHANICAL TO PROVIDE THE REQUIRED SPECIFICATION.

3 of 48 The check synchronizing relay shall be housed in the respective BOP switchboards except for the switchboards located in the TG Building. For the TG Building switchboards the relay shall be part of ECP (i.e. common for 11kV, 3.3 kV & 415V systems.) 3 of 48 Control of incomers and bus-coupler breakers of LV switchgear shall be possible from the EDMS in Main Plant Area and DCS/PLC in BOP areas.

Check synchronizing function ( where applicable) for all MV/LV switchgear Agreed. HOWEVER shall be part of numerical relay. No separate relay is envisaged for the same. SEPARATE RELAY TO BE Owner may please accept. PROVIDED IN ECP/SACP.

3 of 48 All 415 V PCC/PMCC/MCC to be provided with Manual/Auto closing of bus coupler and Auto/Manual live changeover with check synchronizing. A marshalling module shall be provided on each bus of LV Switchgear for interfacing with DCS. Control of incomers and bus-coupler breakers of LV switchgear shall be possible from the EDMS in Main Plant Area and DCS/PLC in BOP areas. The

Bidder has considered Soot blower MCC, which consists of Two Incomer and One Bus-Coupler with auto changeover facility. The Soot Blower motor is having maximum rating of 1.1KW. As per SB operation, maximum of Two No's of Soot blower can be operated at a time and load consumed is 2.2 kW maximum. The soot blower MCC incomer rating is only 32A. Hence, bidder shall be allowed to consider the SFU type incomer.

Bidder understand that Incomer and bus-coupler breakers of LV Switchgear in main plant area and BOP area will be controlled from DCS and respective PLC only.

Control of incomers and bus-coupler breakers of LV switchgear shall be possible from the EDMS and also ECP/SACP in Main Plant Area and DCS/PLC in BOP areas.

The provision as per bidding document shall prevail

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Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

18

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.02.19

4 of 48 Welding sockets in the plant, including welding transformers & Welding PCC and power supply network. For BOP areas welding DBs with isolation transformer shall be provided.

Bidder would like to clarify that welding PCC along with welding transformer is considered for main plant area only. The provision as per bidding For BOP area, welding receptacles shall be fed from respective PCC/PMCC. document shall prevail Owner may please confirm.

19

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.02.23

5 of 48 Waste water & oily waste- from soak of GT, ST, UT & UAT of each unit shall be collected in burnt oil pit. Similarly burnt oil pit shall also be provided in Bunker area, CHP area & AHP area for the auxiliary power transformers.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.04.02 (xii)

Bidder would like to propose the following: 1. Single burnt oil pit for both the units, designed for 100% oil of largest transformer and fire/rain water requirement as per NFPA. 2. For Reactor, Bunker area, CHP area & AHP area for the auxiliary power transformers, each transformer pit shall be designed for 100% oil volume of transformer and fire/rain water requirement as per NFPA. Separate burnt oil pit in these area are not envisaged. Owner may please confirm. As ETAP is internationally accepted & validated software, hence power system study (Load flow, Short circuit, motor starting study) will done through ETAP only and no manual calculation is envisaged for the same. Also, please note that grounding calculation shall be done with Auto grid pro software. Owner may please confirm.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.04.02(xiii)

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.06.11

20

21

22

23

24

1.07.00

1.07.00

7 of 48 All above calculations shall be done manually. Back up ETAP results shall also be submitted for above and load flow study. Bidder shall supply 1 No. ETAP software along with license for Purchaser’s use.

Page 8 of 48

Relay Setting and Relay Co- ordination calculations & graphs/charts. Bidder shall supply 1 No. Relay Testing Unit for Purchaser’s use.

10 of 48 To minimize inventory of spare parts and ease of maintenance all 11kV & 3.3kV and 415V switchgear being shall be of same make (voltage wise). 12 of 48 11 KV system fault level : 50 kA for 1sec.

12 of 48 220 V DC system fault level : 25 kA for 1sec.

Bidder will provide the Relay setting calculations and the same shall be submitted for further approval purpose. Accordigly we propose to exclude the relay testing unit from bidders scope. Owner may please confirm. Bidder would like to maintain same make of Switchgear (voltage wise) to the extend possible. However, if not possible bidder will offer alternative make as per agreed make list. Owner may please confirm. 11 kV system fault level shall be decided based on system study (Load flow, Short circuit, motor starting study) in line with criteria defined in the specification. Fault level of Main DCDB shall be 25 KA, however fault level of Sub DCDB ( fed from main DCDB) shall be selected either 15 KA or 9kA for 1sec based on fault level calculation. Owner may please accept.

The provision as per bidding document shall prevail

ETAP SHALL BE USED FOR ALL CALCULATIONS

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

25

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.09.01

13 of 48 The overall system shall be configured such that failure of any piece of equipment has the minimum possible effect on plant operating capability. In particular, failure of one unit and/or station transformer, dc battery or charger shall not cause reduction in the plant’s generating capability or affect the safe shut down of the unit.

Bidder would like to clarify that incase of failure of one station transformer and one unit transformer simultaneously, respective unit will be on HP-LP bypass mode. In all other scenario, no reduction in plant's generating capacity is envisaged. The provision as per bidding document shall prevail Owner may please accept.

26

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.09.04

Page 13 The battery shall be Lead Acid Plante type. of 48

NI-cd type batteries may be allowed for special applications such as StackerReclaimer for the same. The provision as per bidding Since the battery room for Stackerdocument shall prevail relaimer area does not have the facility for the lead acid type batteries. Owner may please confirm.

27

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.09.06

Page 13 All motors shall be suitable for DOL starting. Soft starters or of 48 star/delta starters are not acceptable.

For specific applications such as compressors star/ delta starters may be allowed for the same. Since the star/ delta starters are the integral part of the compressor skid panel. Owner may please confirm.

13 of 48 Maximum continuous motor ratings shall be at least 15% above design duty point or the maximum load demand of the driven 30 of 48 equipment under entire operating range taking into account voltage and frequency variation. 15 of 48 The isolated phase bus ducts shall run partly indoor and partly outdoor. The isolated phase bus ducts on generator neutral side shall be complete with generator neutral side current transformers,

Bidder would like to clarify that, motor selection criteria as mentioned in the mechanical section shall be followed. Incase no criteria is mentioned for any driven equipment in mechanical section this clause will be followed. Owner may please accept. Bidder would like to clarify that as per Generator OEM proven practice, protections, metering and AVR CTs for generator shall be mounted within the generator turret only. Bidder would like to propose protections, metering and AVR CTs for generator as per OEM proven practice. Owner may please accept.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria _____ Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria ____ Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.12.00

16 of 48 3. Back-up Control Panel (ECP) 4. Back up Control Panel (SACP)

_____ 1.18.12

_____ _____ 21 of 48 Incomers, bus couplers, motor feeders and transformer feeders of 11 kV switchgears shall have numerical type relays for protection and they shall communicate with DCS through Open protocol (IEC 61850).

Bidder would like to clarify that in modern advance power plant, electrical system shall be controlled and monitored from Switchgear SCADA system and hence, very old concept of Electrical Back up control panel (ECP/SACP) is not required now a days.

28

29

30

1.09.06 1.27.06 1.11.02

_____ 1.19.08

_____ _____ Incomers, bus couplers and motor feeders of 3.3 kV switchgears 22 of 48 shall have numerical type relays for protection and they shall communicate with DCS through Open protocol (IEC 61850).

Since, the requirement of electrical system control and monitoring from DCS is already mentioned in referred clause no.1.18.12 and 1.19.08, Owner may please review the requirement of Electrical Back up control panel (ECP and SACP).

The provision as per bidding document shall prevail

Agreed.

SHALL BE AS PER OEM PRACTICE. HOWEVER THERE SHALL BE 6 CTS ON PHASE SIDE AND 5 CTS ON NEUTRAL SIDE.

Control of incomers and bus-coupler breakers of LV switchgear shall be possible from the EDMS and also ECP/SACP in Main Plant Area and DCS/PLC in BOP areas.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply Agreed.

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1.12.01

16 of 48 The following protection schemes shall be provided in the GRP and the protections shall be divided into two groups; each group being 100% redundant and on separate DC supply, so that even if one group of protections is not available or under maintenance, the generator is protected by the other group.

We understand that the referred clause is asking for redundant relays for generator protection only. Same is also in line with the tender drawing number 112-02-1219, Rev0. However for Generator Transformer and Unit Transformer protection main & back up protection shall be provided in separate relay. Redundant protection for Transformer are not applicable. Owner may please confirm.

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.13.01

18 of 48 The GT shall comprise of a bank three Nos. (plus 1 No. spare common for all three units) single phase oil immersed outdoor type transformers with class A insulation and OFAF cooled and shall be provided with Off Circuit Tap Changer (OCTC).

Alternatively bidder would like to propose the followings for Generator Transformer: 1) ODAF (Oil Draft Air Forced) 2) Unit Cooler instead of radiator bank Owner may please accept.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.15.02

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.18.00

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.18.02

36

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.18.07

Page 20 In each bus section of the 11 kV switchgear at least one spare of 48 feeder shall be provided for highest and lowest rating motors and one spare feeder for largest rating Service transformer.

One spare feeder shall be provided for highest and lowest breaker rating in each 11 KV switchgear panel instead of each bus section as mentioned in the clause to optimize the building size and to provide economical solution to The provision as per bidding document shall prevail Owner. Owner may please confirm.

37

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.18.12

Bidder would like to clarify that numerical relays in 11kV Switchgear shall be compatible with IEC 61850 protocol. However, communication of these relays The provision as per bidding through DCS shall be through Modbus/TCP IP protocol. document shall prevail Owner may please accept.

38

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.18.14

21 of 48 Incomers, bus couplers, motor feeders and transformer feeders of 11 kV switchgears shall have numerical type relays for protection and they shall communicate with DCS through Open protocol (IEC 61850). 21 of 48 Heat run (temperature rise) test shall be carried out on one 11 kV Switchgear of each rating.

REQUIRED.

33

34

35

19 of 48 The transformers shall be outdoor, mineral oil filled, ONAN/ONAF/OFAF cooling type and shall be provided with On Load Tap Changer (OLTC) with a range of 10% in steps of 1.25%.

Alternatively bidder would like to propose the followings for Station Transformer: 1) ODAF (Oil Draft Air Forced) 2) Unit Cooler instead of radiator bank Owner may please accept. 19 of 48 There shall be six Nos. 11 KV Station Switchgears for three Units. Bidder would like to inform that as per Key SLD, tender drawing number 11210-0100, Rev0, there are total four (4) number of 11kV Switchgears. Bidder has considered four (4) number of 11kV Station Switchgear as per KSLD only. Owner may please confirm. 19 of 48 1.18.00 11kV SWITCHGEAR Bidder reads the clause as follows: "There shall be four Nos. 11 KV Station Switchgears for two Units. Each 1.18.02 There shall be six Nos. 11 KV Station Switchgears for three Units. Each Station Switchgears shall be fed from respective Station Switchgears shall be fed from respective secondary winding of Station transformers." secondary winding of Station transformers. Owner may please issue amendment.

Bidder would like to clarify that type test report of heat run test for same of higher rating switchgear will be submitted for owner acceptance during detail engineering. Owner may please confirm.

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

CONFIMED.

CONFIRMED.

The provision as per bidding document shall prevail

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Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.19.05

Page 22 In each bus section of the 3.3 kV switchgear at least one spare of 48 feeder shall be provided for highest rating motor and one spare feeder for lowest rating Motor.

One spare feeder shall be provided for highest and lowest breaker rating in each 3.3 KV switchgear panel instead of each bus section as mentioned in the clause to optimize the building size and to provide economical solution to The provision as per bidding Owner. Owner document shall prevail may please confirm.

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.19.08

22 of 48 Incomers, bus couplers and motor feeders of 3.3 kV switchgears shall have numerical type relays for protection and they shall communicate with DCS through Open protocol (IEC 61850).

Bidder would like to clarify that numerical relays in 3.3kV Switchgear shall be compatible with IEC 61850 protocol. However, communication of these relays through DCS shall be through Modbus/TCP IP protocol. Owner may please confirm. Bidder would like to clarify that type test report of heat run test for same of higher rating switchgear will be submitted for owner acceptance during detail engineering. Owner may please confirm. Bidder proposes to use 2X 100 % configuration for transformer and if the max. load exceed 2.15 MVA then bidder may consider 3X50 % config also. Owner may please accept.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria _________________ Vol. IV/ Ch 9: Service Transformers Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.22.06

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42

43

44

45

46

1.19.10

1.22.03

1.22.11 ________ 9.05.08 i)

1.24.09

1.24.10 (b)

22 of 48 Heat run (temperature rise) test shall be carried out on each rating 3.3 kV Switchgears. 23 of 48 Each switchgear/MCC/distribution board shall be fed by 2x100% transformers/feeders and these shall be rated to carry the maximum load expected to be imposed.

23 of 48 Additional starting & running of one largest stand by motor with driven equipment shall also be considered while sizing the transformer. The motor terminal voltage during above operations shall be within specified limits. 23 of 48 11 KV / 0.433 KV transformers shall be provided with Off Circuit _______ Tap Changer of ± 5% in steps of 2.5% per tap. ______________________________________________ _ 10 of 17 Off-circuit taps as specified shall be provided on the high voltage winding with a tap range of ± 5% in the steps of 2.05%.

Bidder would like to clarify that only starting of largest standby motor shall be considered for sizing of transformer. Owner may please accept. Bidder understands that both these clauses (i.e. clause 1.22.11 of Vol- IV, Chapter-1 & clause 9.05.08.i of Vol- IV, Chapter-9) are contradictory to each other. Bidder understand that same shall be read as "with a tap range of ± 5% in the steps of 2.5%."

24 of 48 The AC control supply voltage for motors rated below 90 kW shall Bidder would like to propose 2 x 100 %, 415/110V control transformer for be 110V AC. For this purpose each motor feeder of PMCC/MCC each bus section for AC control supply of motor feeder rated upto 90kW. shall be provided with suitable rated 415/110V Control Transformer. Owner may please accept. 25 of 48 Non Intelligent Draw out type MCC - Soot Blower MCC

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

BIDDER TO PROVIDE 2X100% CONFIRGURATION FOR TRANSFORMER. INCASE RATING OF TRANSFORMER EXCEEDS 2.5MVA THEN 3 X50% CONFIRGURATION SHALL BE PROVIDED.

The provision as per bidding document shall prevail

Off-circuit taps as specified shall be provided on the high voltage winding with a tap range of ± 5% in the steps of 2.5%.

Agreed.

Bidders clarifies that Soot Blowing operation timing is minimum and the Incomer rating is 32A SFU. Hence, Soot Blower MCC shall be Non Intelligent The provision as per bidding document shall prevail fixed type.

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49

50

51

52

Section / Part / Chapter / Volume

Clause No.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.25.01

Vol IV / Chapter1 Electrical Scope of Work and Design Criteria _____ Vol.IV/Chapter-14 AC & DC Motors Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.27.02 _____ 14.04.01

Vol IV / Chapter1 Electrical Scope of Work and Design Criteria

1.27.05

1.27.01

1.27.04

1.29.01 Vol IV / Chapter1 __________ Electrical Scope of 1.29.03 Work and Design Criteria __________________ _ Vol IV / Chapter1 Electrical Scope of Work and Design Criteria

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

25 of 48 Numerical type protective relays shall be provided to isolate the faulty equipment and system as early and as expeditiously possible. All numerical relays shall communicate with DCS through Open protocol (IEC 61850). 30 of 48 Motors rated upto and including 160 kW shall be connected to 415V, 50 Hz AC supply. Motors rated above 160 kW upto and including 1500 kW shall be connected to 3.3 KV, 50 Hz supply. Motors rated above 1500 kW shall be connected to 11 kV, 50 Hz supply. 30 of 48 … … energy efficiency level IE3 as per IS 12615:2011…. … _____ _____ 4 of 20 … … Efficiency class-IE2, conforming to IS 12615, or IEC:6003430.

Bidder would like to clarify that numerical relays shall be compatible with IEC 61850 protocol. However, communication of these relays through DCS shall be through Modbus/TCP IP protocol. Owner may please confirm. Bidder would like to propose LV Motor upto and including 200kW to be fed from LV Switchgear except for CHP. For CHP motor upto and including 160kW shall be fed from 415V system. Owner may please accept.

30 of 48 Locked rotor current of the LV motor shall not exceed 600% of full load current subject to 20% IS tolerance.

Bidder would like to clarify that locked rotor current for LV motor shall be as per IS 12615:2011 for IE3 motor with applicable tolerance value. Electrical system shall be designed accordingly. Owner may please accept.

Page 30 Motors rated 90 kW and & above up to of 48 160KW shall be ACB controlled with numerical relays

There is a discrepancy in Class of efficiency required for LT motors at two different clause of tender specification. Owner may please clarify.

For CHP area, Motors rated 90 kW and & above up to 160KW shall be suitable for contactor controlled having MCCB and Overload Relay. Due to frequent switching of the drives in CHP area, contactor controlled is envisaged in LT, 415V switchgear. Owner may please confirm.

32 of 48 For this purpose, 2 x 100% rated 220 V Battery charger (Float cum Bidder would like to propose battery back-up time for 30 mins as per _______ Boost) for each battery and 2 x 100% rated battery for catering DC prevailing practice of NTPC and other utilities. 32 of 48 loads of each unit and common auxiliaries for Two (2) hours has Owner may please accept. been considered. ________________________________________________ All the batteries shall be sized for the required load and Two (2) hour load cycle, taking into account of temperature correction, design margin and aging compensation factors.

Owner's Reply

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

IE3 MOTORS SHALL BE SUPPLIED.

Agreed.

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.29.01

32 of 48 Three sets of above 220 V DC Systems shall take care of DC loads of 3 units and DC loads of station system.

Bidder would like to clarify that Two (2) sets of battery system are envisaged. Each DC System shall be designed to take care of DC loads of one (1) unit and 50% of station system. Owner may please accept.

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.29.03

32 of 48 Battery shall be of storage type plante lead acid. Battery shall be sized for continuous operation at design ambient of 50 deg. C.

Alternatively bidder would like to propose Ni-Cd battery as per prevailing practice of NTPC and other utilities. Bidder would like to clarify that minimum electrolyte temperature shall be considered 10 Deg C higher then the ambient temperature for battery sizing. Owner may please accept.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.30.02

55

56

57

33 of 48 i) For 11kV - 50kA - 0.2 sec for outgoing motor feeders and transformer feeders and 50kA- 1sec-for tie and incomer feeders. ii) For 3.3kV - 40kA - 0.2 sec for outgoing motor feeders and transformer feeders and 40kA-1 sec-for incomers & tie feeders. iii) For 415V - 50kA - 0.25 sec for motor feeders and 50kA-1sec-for incomer & tie feeders.

Bidder would like to propose the following: i) For 11kV - * kA - 0.16 sec for outgoing motor feeders and transformer feeders (provided with instantaneous protection) and *kA- 1sec-for tie and incomer feeders. ii) For 3.3kV - *kA - 0.16 sec for outgoing motor feeders and transformer feeders (provided with instantaneous protection) and *kA-1 sec-for incomers & tie feeders. iii) For 415V - 50kA - 0.16 sec for motor feeders and 50kA-1sec-for incomer & tie feeders. *- Shall be as per 11kV/3.3kV switchgear fault level. Owner may please accept.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.30.04 1.30.06 1.30.07

34 of 48 For ACB / MCCB/MPCB protected circuits the conductor size shall The cable shall be sized based on 90% voltage at load end during running depend upon full load current subject to voltage drop limited to 3% conditions and 80% voltage at motor terminals under starting conditions. during running of all feeders and 15% during starting of motors having rigid coupling.

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.30.10 (iii)

34 of 48 Above 19 core two or more of above cables

Bidder would like to propose 24 core cable also for control circuit. Owner may please accept.

Owner's Reply 2 X 100% set of 220V battery with associated float cum boost charger for main plant and station loads of each unit. Also one No. spare float cum boost charger shall be provided for the Main Plant Area. 2 X 100% set of battery with associated float cum boost charger for other areas.

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

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60

61

62

Section / Part / Chapter / Volume Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

Clause No. 1.30.10 (iv)

1.33.01

Page no.

Bid Specification Stipulation

34 of 48 For DC system only single core cables shall be used.

Statement of Prebid Queries & Clarification Bidder would like to use 2C cable for DC circuit. Owner may please accept.

Owner's Reply

Agreed.

36 of 48 The termination kits shall be suitable for termination of the cables to indoor switchgear or to a weatherproof cable box of an indoor/outdoor mounted transformer/motor. The termination kits shall preferably be as of the following types:a) PUSH ON type for LV power cables.

As per standard practice, termination kit is envisaged for MV (11 & 3.3 kV) cable only. For LV cable termination is envisaged through suitable lugs.

1.35.03

38 of 48 The steel conduit shall be encased in concrete.

Bidder would like to clarify that steel conduits shall be used for directly buried application only. PVC conduit will be encased in concrete. Agreed. Owner may please accept.

1.36.02 (iii)

39 of 48 The minimum design vertical spacing for trays shall be 300 mm measured from the bottom of the upper tray to the top of the lower tray.

Bidder would like to propose bottom to bottom spacing between cable tray of 300 mm in BTG area due to space constraints. For BOP area, spacing as per The provision as per bidding tender requirement shall be followed. document shall prevail Owner may please accept.

41 of 48 _______ 41 of 48 _______ 25 of 30

All the three referred clauses are contradictory to each other. Bidder understands that as per chaper -23 of illumination system, clause no 23.02.00, Lighting fixtures with lamps and accessories and LED type fixtures for main roads, secondary roads & perimeter compound lighting. Bidder presumes that LED luminaire shall be provided only for road and peripherial lighting and rest all the luminaires shall be of conventional Mercury/Sodium vapour lamp. Owner may please confirm.

1.38.05 Vol. IV/ Chapter-1: ________ Electrical Scope of 1.38.06 Work and ________ Design Criteria __________________ ANNEXURE-I _ Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria __________________ Volume IV: Electrical Works, Ch 23: Illumination System

Only LED fixtures shall be provided. ______________________________________ For yard illumination, flood lights would be installed at suitable locations to provide the requisite level of illumination. Polemounted high-pressure sodium vapor fixtures would be used for approach roads. ________________________________________ Type of Luminaire

Owner may please accept.

Agreed.

ONLY LED LIGHTS TO BE PROVIDED FOR THE ENTIRE PLANT.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

63

Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.38.05

41 of 48 Only LED fixtures shall be provided.

As per chaper -23 of illumination system, clause no 23.02.00 Lighting fixtures with lamps and accessories and LED type fixtures for main roads, secondary roads & perimeter compound lighting. Bidder presumes that LED luminaire shall be provided only for road and peripherial lighting and rest all the luminaires shall be of conventional Mercury/Sodium vapour lamp. Owner may please confirm.

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1.44.00

Page 45 During design stage adequate space shall be provided for of 48 expansion of board on either side to accommodate addition of panel to take care of unforeseen factors.

All the boards shall be designed based on the actual feeder requirement and spare philosophy as per the NIT specifications. Accordingly Equipment layout shall be prepaired. Separately Agreed. additional space may not be required. Owner may please confirm.

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Vol. IV/ Chapter-1: Electrical Scope of Work and Design Criteria

1.44.02 (v)

45 of 48 The minimum clear height (excluding roof beam) shall be 3.0 metres.

We understand that Elevations at different floors of TG building are fixed as per tender drawing TG Building GA. Clearance/Height of various Cable Vault, Switchgear Room etc. within TG building shall be as per approved civil & structure design. For balance buildings other then TG building Clearance/Height for Cable Vault, Switchgear Room etc. shall be maintained as per specification. Owner may please accept.

Volume IV:Ch-3 : Power Transformer

3.03.03, x)

66

Page 6 of 42

The LV windings of Station Transformers and Unit Transformers shall be designed to withstand the frequent surges of DOL starting of Boiler feed pump motor at a very low power factor.

As per Tender SLD (112-10-0100, Rev0), MD BFP is connected to Station switchgear only and hence starting of BFP is not envisaged on Unit transformer.

The provision as per bidding document shall prevail

Agreed.

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Section / Part / Chapter / Volume Volume IV:Ch-3 : Power Transformer

Clause No. 3.04.09, v), c)

3.04.09, v), ii)

Page no.

Bid Specification Stipulation

Page 12 2 nos. of 60% capacity radiators. Each radiator shall be provided of 42 with 2x100% capacity oil pump. Total capacity of unit coolers furnished for each transformer shall be minimum 120% of actual requirements.

Statement of Prebid Queries & Clarification Bidder would like to propose the followings: 1) Radiator Bank 2) Unit Cooler instead of radiator bank Owner may please accept.

Owner's Reply

Each power transformer (GT/ST/UT) shall be provided with 2x60% radiator banks. In case of radiator banks, the transformer shall be capable of operating continuously under natural cooled condition up to the specified load. The forced cooling equipment shall come into operation by pre-set contacts of winding temperature indicator and the transformer shall operate as a forced cooling unit. Cooling shall be so designed that during total failure of power supply to cooling fans and oil pumps, the transformer shall be able to operate at full load for at least ten (10) minutes without the calculated winding hot spot temperature exceeding 140°C. Further, cooling shall be so designed that during total failure of cooling fans and oil pumps of one radiator bank, the transformer shall be able to operate at full load for at least ten (10) minutes without the calculated winding hot spot temperature exceeding 115°C. Each radiator bank of GT/ST shall have standby pump also.

68

69

70

Volume IV:Ch-3 : Power Transformer

1.12 (a)

Volume IV:Ch-3 : Power Transformer

1.15

Volume IV:Ch-3 : Power Transformer

1.11.2

37 of 42 DATA SHEET : GENERATOR TRANSFORMER Insulation level :HV- (SI/Li/AC)420kV side : 1300kVp/1050kVp/570kVrms

There seems to be some typo mistake for mentioning BIL level.

37 of 42 DATA SHEET : GENERATOR TRANSFORMER Short-circuit impedance at 75ºC at principal tap - 15% (max) on 275 MVA base without positive tolerence

Bidder requests that Generator transformer impedance at principal tap may be selected between 14% & 16% as against specified value of 16%. However, bidder will limit the range of transformer impedance (lowest to highest - including tolerance) from 12.5% to 17.5% as specified. Owner may please confirm.

37 of 42 DATA SHEET : GENERATOR TRANSFORMER Temperature rise above design ambient temperature (a) In oil by thermometer - 40 degC (b) In winding by resistance - 45 degC

Bidder request Owner to amend specification as below in line with IEC 60076/IS 2026: Temperature rise above design ambient temperature (a) In oil by thermometer - 50 degC (b) In winding by resistance - 55 degC

Purchaser may confirm the exact requirement.

SHALL BE 1425KVP/630KV.

Short-circuit impedance at 75ºC at principal tap - 15% (max) on 275 MVA base without positive tolerence

The provision as per bidding document shall prevail

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73 74

75

76

77

Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Volume IV:Ch-3 : Power Transformer _____________ Vol.VII Tender drawings

1.15 ___________ 112-02-1219 Metering and Protection SLD

37 of 42 DATA SHEET : GENERATOR TRANSFORMER ______ Short-circuit impedance at 75ºC at principal tap - 15% (max) on 275 MVA base without positive tolerence _____________________________ GENERATOR TRANSFORMER Z=13.5%

There is discrepancy between Short-circuit impedance of GT mentioned in datasheet and Protection SLD. Bidder request Owner to review.

Volume IV:Ch-3 : Power Transformer

11.2

39 of 42 DATA SHEET : STATION TRANSFORMER 11.2 Temperature rise above design ambient temperature (a) In oil by thermometer - 40 degC (b) In winding by resistance - 45 degC

Bidder request Owner to amend specification as below in line with IEC 60076/IS 2026: Temperature rise above design ambient temperature (a) In oil by thermometer - 50 degC (b) In winding by resistance - 55 degC

40 of 42 DATA SHEET : STATION TRANSFORMER TRANSFORMER BUSHING Voltage class kV (rms): HV- 550 kVrms 41 of 42 DATA SHEET : UNIT TRANSFORMERS Temperature rise above design ambient temperature (a) In oil by thermometer - 40 degC (b) In winding by resistance - 45 degC

Bidder propose Owner to consider Station Transformer bushing of voltage class 420 kVrms for 400kV system which is in line with voltage class of Generator Transformer HV Bushing. Bidder request Owner to amend specification as below in line with IEC 60076/IS 2026: Temperature rise above design ambient temperature (a) In oil by thermometer - 50 degC (b) In winding by resistance - 55 degC

41 of 42 DATA SHEET : UNIT TRANSFORMERS Impedance at 75 deg.C on 40MVA base : On Principal Tap - HV-LV -9%

Impedance of the Unit transformer shall be selected based on system study.

Volume IV:Ch-3 : Power Transformer

21.1

Volume IV:Ch-3 : Power Transformer

11.2

Volume IV:Ch-3 : Power Transformer Vol.IV/Chapter-3 _____________ Vol.VII Tender drawings Vol.IV/Chapter-8:11 KV & 3.3 KV Switchgear

14.0(i)

14.0 ___________ 112-02-1219 Metering and Protection SLD 8.04.01 v)

41 of 42 Impedance at 75 deg.C on 40MVA base ______ i) On Principal Tap- HV-LV: 9% ___________________________ Unit Transformer- Z=11.5% 6 of 36 Forced cooling for HV breakers (11 kV & 3.3 kV) and HV switchgear is not acceptable.

Owner's Reply

Short-circuit impedance at 75ºC at principal tap - 15% (max) on 275 MVA base without positive tolerence

Purchaser may confirm. There is discrepancy between Short-circuit impedance of UT mentioned in UT datasheet and Protection SLD. Bidder request Owner to resolve the discrepancy. Switchgear breaker with normal cooling is available in market upto 3150A rating only. For breaker above 3150A, the breaker is always with forced cooling. Hence, bidder suggest to allow for forced cooling of breaker for rating above 3150A.

The provision as per bidding document shall prevail

Agreed

The provision as per bidding document shall prevail

Z=10%

REFER REPLY AT SL NO. 75 ABOVE.

Agreed. HOWEVER REDUNDANCY TO BE PROVIDED FOR THE COOLING FANS

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Section / Part / Chapter / Volume Vol.IV/Chapter-9 : Service Transformers

Clause No. 9.01.01

Page no.

Bid Specification Stipulation

2 of 17 The scope of supply shall include Cast Resin Encapsulated dry type transformers of ratings to be decided by the Bidder based on selection criteria given in this specification.

Statement of Prebid Queries & Clarification "Bidder would like to clarify that world class OEMs like GE manufactures LV dry transformers with VPI (Vacuum Pressure Impregnated) type using Nomex as the insulating material on the conductors. Owner is requested to accept VPI technology in addition to Cast resin technology indicated in tender specification for Dry Type Transformer."

79

Vol.IV/Chapter-9 : Service Transformers

9.03.08

80

Vol. IV/Chapter-9: Service Transformers

9.05.12 ii)

81

Vol.IV/Chapter-11 : 11.01.11 415V Switchgears and DC Boards

5 of 17 The transformer shall be capable of withstanding the short circuit Bidder understands that the minimum period indicated in referred clause is stresses due to a terminal fault on any one winding with full voltage two (2) seconds. Owner may please confirm. maintained on the other winding for minimum period of three (2) seconds. Necessary calculation confirming thermal ability shall be submitted with bid.

11 of 17 Wiring shall be done with……………… Minimum wire size shall be Bidder understands that 2.05 sq mm shall be read as 2.5 stranded copper 2.05 sq. mm stranded copper. Not more than two wires shall be wire as 2.05sq mm does not seem to be standard wire size. Owner may connected to a terminal. please confirm.

3 of 48 All 415V PCC, PMCC & MCC shall generally be of intelligent type compatible with IEC 61850 Communication protocol. However utility MCCs as mentioned in the single line diagram shall be nonintelligent type. . A marshalling module shall be provided on each bus of LV Switchgear (PCC, PMCC, MCC) for interfacing with DCS. Control of incomers and bus-coupler breakers of LV switchgear shall be possible from the DCS. The check synchronizing relay shall be housed in the respective switchboards. Dummy panels shall be integral part of the LV Switchgear and of same size.

Owner's Reply

Bidder clarifies that check synchronizing relay shall be housed in the respective switchboards (as applicable).

The provision as per bidding document shall prevail

The transformer shall be capable of withstanding the short circuit stresses due to a terminal fault on any one winding with full voltage maintained on the other winding for minimum period of two (2) seconds. Necessary calculation confirming thermal ability shall be submitted with bid. Wiring shall be done with……………… Minimum wire size shall be 2.5 sq. mm stranded copper. Not more than two wires shall be connected to a terminal.

Agreed. HOWEVER SEPARATE RELAY TO BE PROVIDED IN ECP/SACP

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83

Section / Part / Chapter / Volume Vol IV/Chapter13: Local Push Button Stations & Misc. Equipments

Clause No. 13.03.03 & 13.03.04

Vol.IV/Chapter-14 : AC 14.13.05 (ii) & DC Motors

Page no. 2 of 4

Bid Specification Stipulation All PBs shall be push to actuate type and the stop PB shall be lockable in off position as per the scheme requirement Emergency local stop push button should not be lockable. Emergency push buttons shall be stay put type.

6 of 20 Motors (above 1000 KW upto 3000 KW) .……… 600%. Not subject to any positive tolerance

Statement of Prebid Queries & Clarification As per bidder standard practice , the following is proposed : All HT/LT Drives Emergency Stop PB is envisaged. Emergency Stop PB is Stay put Type, with Mushroom head. Lockable and Key removable in "OFF" Position.

The clause 14.13.05 & 1.27.04 are contradicting. Please clarify the exact requirement of tolerance.

Vol.IV/Chapter-14 : AC 14.16.00 & DC Motors

7 of 20 STARTING TIME 14.16.01 For motors with starting time upto 20 secs. at minimum permissible voltage during starting, the locked rotor withstand time under hot condition at highest voltage limit shall be at least 2.5 secs. more than starting time. 14.16.02 For motors with starting time more than 20 secs. and upto 45 secs. at minimum permissible voltage during starting, the locked rotor withstand time under hot condition at highest voltage limit shall be at least 5 secs. more than starting time. 14.16.03 For motors with starting time more than 45 secs. at minimum permissible voltage during starting, the locked rotor withstand time under hot condition at highest voltage limit shall be more than starting time by at least 10% of the starting time. 14.16.04 At no stage, speed switch shall be provided to achieve requirements mentioned in Clause No 14 0114 01 to 14 0114 03

Agreed.

As per Chapter-1/ Volume IV Page 30 of 48 Clause 1.27.04 "Locked rotor current of the HV & MV motors rated 3000 kW and below shall be limited to 600% (subject to 20% IS tolerance) of the full load current of the motors and motor rated above 3000 kW and without VFD shall be limited to 450% (inclusive of 20% tolerance) of full load current of the motor. Locked rotor current of the LV motor shall not exceed 600% of full load current subject to 20% IS tolerance".

84

Owner's Reply

Locked rotor current of the HV & MV motors rated 3000 kW and below shall be limited to 600% (subject to 20% IS tolerance) of the full load current of the motors and motor rated above 3000 kW and without VFD shall be limited to 450% (inclusive of 20% tolerance) of full load current of the motor. Locked rotor current of the LV motor shall not exceed 600% of full load current subject to 20% IS tolerance.

Bidder clarifies that as per the Motor OEM standard proven practice is to provide the Speed Switch, if the specification criteria not met . Hence, we request to delete the clause no. 14.16.04. "At no stage, speed switch shall be provided to achieve requirements mentioned in Clause No. 14.0114.01 to 14.0114.03"

ONLY IN CASE OF HIGH INERTIA DRIVES LIKE FAN DRIVES, SPEED SWITCH IS ACCEPTABLE.

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87

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Vol.IV/Chapter-14 : AC 14.21.00 & DC Motors

8 of 20 Method of cooling shall be IC 411 (TEFC), IC 511 (TETV) or IC 611 (CACA). However, motors rated 3000kW or above can be closed air circuit water cooled (CACW).

As per bidder experience , the following is proposed : Method of cooling shall be IC 411 (TEFC), IC 511 (TETV) or IC 611 (CACA) or CACW.

Vol.IV/Chapter-14 : AC 14.39.00 & & DC Motors 14.40.00

15 of 20 HV & MV motor shall be provided with four (4) Nos. simplex or two (2) Nos. duplex platinum resistance temperature detectors (RTDs) in each phase embedded in stator winding at locations where high temperatures are expected. In addition one (1) duplex type RTD shall be provided in each bearing. The RTDs shall be 3 wire duplex platinum resistance type having a value of 100 ohms at 0 Deg.C HV & MV motors shall be provided with dial type two (2) bearing temperature indicators and shall have two (2) sets of contacts, each set having 2 NO + 2 NC contacts rated for 5A at 240V AC and 0.5A at 220V DC. One set shall be set to operate at lower value to give alarm and other set at a higher value to trip the motor

As per Motor OEM standard , the following quantities is proposed: Winding RTD 12 Nos Simplex or 6 Nos Duplex RTD will be provide.RTD - 3 Wire Type Bearing RTD 2 Nos Duplex RTD / Bearing will be provided. RTD - 3 Wire Type Dial Type Indicator 1 No DTT / Bearing will be provided. For local monitoring

Vol.IV/Chapter-15 : Electrical Actuators with Integral Starters

Vol- IV/Chapter-16: Electricals of Elevator, EOT Cranes, Hoist and EOT U/S Crane

15.06.03 (i) (ii)

16.03.03 iii)

6 of 9

Each motor actuator shall have Six (6) rotary drum position limit switches with two for open each with 2 NO + 2NC contacts and two for close each with 2 NO + 2 NC contacts positions, each with adjustable setting between fully open and fully closed positions. Each rotary drum limit switch shall have two (2) limit switches for intermediate open position each with 2 NO + 2 NC contacts. The limit switches shall have capacity of 5A at 240V AC or 0.5A at 220V DC. Each motor actuator shall also have two (2) torque limit switches with four (4) normally opened and four (4) normally closed contacts each

21 of 25 Each transformer shall be provided with tappings at +5% & + 10% on the primary.

As per OEM design , the following is proposed : Each motor actuator shall have switches as follows: Limit Switches with contacts Open - 2NO+2NC Close - 2NO+2NC Torque Switches with contacts Open - 2NO+2NC Close - 2NO+2NC Intermediate Limit Switches with contacts Open - 2NO+2NC Close - 2NO+2NC Position feedback Position Transmitter is provided for Inching Type application actuator

Owner's Reply

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

The provision as per bidding document shall prevail

Bidder understands that this clause shall be read as "Each transformer shall be provided with tappings at ±5% &±10% on the primary". Owner may please Agreed confirm.

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92

93

Section / Part / Chapter / Volume Vol.IV/Chapter-20 : Cabling System

Vol.IV/Ch-24 : Earthing & Lightning Protection Vol.IV/Chapter-25 : Construction Power Supply ____________ Vo.II/Chapter-1: Intent of Specification

Clause No. 20.08.01 (ii)

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

10 of 21 Horizontally running cable trays shall be clamped by bolting to Bidder proposes to Weld the Cable Trays with Cable tray Support (For both cantilever arms and vertically running cable trays shall be bolted to vertically and horizontally running Cable trays). main support channel by suitable bracket/clamps on both top and bottom side rails at an interval of 1500 mm. For vertical cable risers/shafts cable trays shall be supported at an interval of 1000mm. Fixing of cable trays to cantilever arms or main support channel by welding shall not be accepted

13.0 _____ -

4 of 4 TERMINAL POINTS Bidder understands that the terminal point for Construction Power shall be at _____ (a) Incoming 33 kV supply at two point inside the plant boundary by 11 kV voltage level since Owner has already constructed 33/11 kV substation. 4 of 12 STPL. _______________________________ Agreed. Following works will be excluded from the bidder’s scope: e) Construction of Substation for Construction Power (33/11 kV Substation already constructed by Owner)

29.04.01

94

Vol.IV/Ch 29: 400 kV Gas Insulated

29.04.03

95

Vol.IV/Ch 29: 400 kV Gas Insulated Switchgear

29.05.06, i)

Vol.IV/Ch 29: 400 kV Gas Insulated Switchgear

29.05.24, i)

2 of 71 400 kV GIS i) 400 kV GIS comprises the following major components a) The 400 kV GIS shall have following bays: aa) Generator Transformer bays : 2 bb) Line bays : 4 cc) Bus Reactor Bay : 1 dd) Bus PT Bay : 2

We understand that mentioned fault is only for earthing conductor sizing. Purchaser may confirm.

PREFABRICATED TYPE CABLE SUPPORTS TO BE USED FOR THE ENTIRE PLANT.

Page 3 of 12

Vol. IV / Ch 29: 400 kV 29.02.02 Gas Insulated Switchgear

Fault current for the earthing system shall be designed for 50 KA for duration of 1 sec.

Owner's Reply

24.03.02, ii)

Vol.IV/Ch 29: 400 kV Gas Insulated Switchgear

96

Page no.

The provision as per bidding document shall prevail

Station transformer bay is not mentioned in the referred clause. Owner may please check and update. Refer addendum -01

Page 12 The basic system connection is shown in Drawing No.D-0444-112- Mentioned drawing is missing in the tender. of 71 26-01: SINGLE LINE DIAGRAM of 400 kV GIS Substation Purchaser may provide the same. Page 13 Lightning arresters for generator transformer and stand by of 71 transformer shall be mounted on a structure placed near the respective transformer. Page 23 Fast acting earthing switches shall be located at the busbar and at of 71 all external HV connections of feeders like HV cables or overhead lines or transformer connections.

Bidder understand that standby transformer mentioned here is not applicable for this configuration. Owner may please confirm. Fast acting earthing switches will be provided for line feeders only as per prevaling industry practice. Owner may please confirm.

Page 33 The typical layout for 400 kV GIS Substation is shown in drawing of 71 No. D-0444-112-26-1001 is only indicative.

Mentioned drawing is missing in the tender. Purchaser may provide the same.

Refer addendum -01 READ STANDBY TRANSFORMER AS STATION TRANSFORMER

Agreed.

Refer addendum -01

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Section / Part / Chapter / Volume

Clause No.

Vol.IV/Ch 29: 400 kV 29.12.01,A, Gas Insulated Switchgear Vol.IV/Ch 30: 30.03.01(vii) Substation Automation System (SAS)

99

Vol- IV/Chapter-33: Emergency Diesel Generator Set

33.05.10 iii)

100

Vol.VII Tender drawings _____________ Vol.VII Tender drawings

112-10-0100 Single Line Diagram ___________ 112-02-1219 Metering and Protection SLD Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2 Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2 Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2 Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2 Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2

101

102

103

104

105

Vol.VII Tender drawings Vol.VII Tender drawings Vol.VII Tender drawings Vol.VII Tender drawings Vol.VII Tender drawings

Page no.

Bid Specification Stipulation

Page 43 LINE PROTECTION RELAY PANEL of 71

Statement of Prebid Queries & Clarification We understand that all protection functions mentioned( under cited clause) shall be part of Main-1 & Main-2 composite protection relay only.

Sheet 4 Bidder shall offer the Bay Controller Unit (BCU) (one HOT and one As per standard utility practice, one BCU shall be provided for each bay. of 38 COLD) for each bay in a diameter (One diameter will consists of Additionally bidder would like to propose BCU as a part of LCC three bays) at 400 kV level. Purchaser may accept the same. 12 of 31 e) Permissible voltage variation for satisfactory operation at rated kVA: +10% f) Permissible frequency variation: +5% -

-

-

-

-

-

Bidder understands that voltage variation shall be ±10% and frequency variation shall be ±5% as mentioned in Vol-IV, chapter-1, Clause No. 1.06.02.Owner may please confirm.

Unit Transformer- 40/32 MVA ____________________________ Unit Transformer- 25/31.5 MVA

There is discrepancy between rating of UT mentioned in Main Plant SLD and Protection SLD. Bidder request Owner to resolve the discrepancy.

Fork arrangement has been proposed between the two buses of the same transformer.

Bidder understands that, the referred clause is not applicable to bidder considering present connections shown in SLD. Owner may please confirm.

Transformer details: 3. Unit Transformer: 2x100% per unit.

Bidder would like to clarify that the unit transformer shall be sized for 2x50% per unit requirement. Owner may please update.

Transformer details: Package No: STG, SG, BOP

Bidder understands that the package no. indicated in SLD is not applicable as this tender is EPC tender considering all package as per tender spec.

Outgoing feeder for FGD Plant (20MW)

Bidder would like to clarify that the FGD system is part of EPC tender hence only provision of feeder requirement mentioned in SLD is not clear. Owner may please clarify.

Rating of Electrical Equipment

Owner's Reply

Agreed

Agreed Agreed. HOWEVER TRANSIENT VOLATGE DIP SHALL NOT BE MORE THAN 15%.

MINIMUM RATING OF UA IS 40/32MVA.

Bidder understand that rating of electrical equipment GT, ST, UT, UAT, Aux Transformer, IPBD etc. as mentioned in the KSLD and Tender specification are indicative only and not binding for EPC contractor. Rating of all electrical equipment shall be arrived as per the criteria mentioned in the tender specification and submitted to owner for review and approval during detail engineering.

Agreed

Agreed.

Agreed.

Agreed.

RATINGS MENTIONED ARE THE MINIMUM RATINGS INDICATIVE.

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Sr. No. 106

107

Clause No.

Page no.

Vol.VII Tender drawings

Single Line Diagram : 11210-0100 Rev.0, Sheet 1 of 2

-

-

-

-

Bid Specification Stipulation Number and location of LV Load centers

Electrical for Raw Water Pump House.

Statement of Prebid Queries & Clarification Bidder understand that number and location of LV load center as mentioned in the KSLD and Tender specification are indicative only and not binding for EPC contractor. EPC Contractor will decide number and location of LV load center as per geographical position of load centers. Owner may please confirm.

Owner may please specify following for Raw Water Intake Pump House. 1. Voltage level in kV for interconnection line between plant and RWPH location. 2. Details of route survey and drawing for interconnecting line corridor. 3. Location of substation at RWPH.

Owner's Reply

THEY ARE THE MINIMUM REQUIREMENT. BIDDER TO PROVIDE ADDITIONAL LV LOAD CENTRES IF REQUIRED BASED BASED ON GEOGRAPHICAL REQUIREMENT. 1. 11 kV 2. ENCLOSED IN ADDENDUM. 3. ON THE BANKS OF RIVER GANGA IF THE PUMPHOUSE IS INSIDE THE RIVER.

108

-

-

-

Electrical for Raw Water Pump House.

Owner may please confirm for following. 1. Right of way for interconnection line shall be in Owner's scope. 2. Permissions and statutory clearance for interconnection line works shall be CONFIRMED. in Owner's scope.

109

General

-

-

Discrepancies in the voltage levels

We have Agreed various discrepancies in the voltage level in tender document and Tender SLD for Power Transformers. For clarity we have considered the following voltage levels: 1. Generator Transformer: 400/*kV 2. Station Transformer: 400/11.5/11.5 3. Unit Transformer: */11.5/11.5kV According to the above voltage class, BIL and rated voltage of associated equipment i.e. LA etc will be selected based on IEC standard. Owner is requested to confirm the same.

Refer Addendum -01.

110

General layout Plan

-

-

-

Bidder understands that dismantling or re-routing, if required, of any EHV/HT/LT lines passing through Buxar power plant area shall be in owner`s scope. Owner may please confirm CONFIRMED.

111

General

-

-

Discrepancies between description of Provenness Criteria and Attachment-3K

Bidder understands that in case of discrepancy between description of Provenness Criteria and Attachment-3K, description of provenness criteria will govern and Attachment-3K will be amended accordingly by the bidder during bid submission.

STRINGENT AMONGST THE TWO TO BE FOLLOWED.

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1

Section / Part / Chapter / Volume

Clause No.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

C&I

Vol. V: PART A

2.04.03

2

Vol. V: PART A

3

Vol. V: PART A

2.03.02

4

Part B/Ch 3: DDCMIS

3.52.02 & 3.52.03

5

DISTRIBUTED DIGITAL CONTROL, MONITORING & INFORMATION SYSTEM

2.01.00, viii,1

6

Page no.

Vol. V: PART A

2.03.05

Cross HMI operation is applicable for this package through which drives in one HMI (DDCMIS) can be controlled from a different HMI We have considered Cross HMI operation at group levels for drives through 6 of 100 (DDCMIS) through authorized access. Refer Part-B, subsection Soft link; Individual drive level control is not recommended and shall not be chapter 3, DDCMIS for details envisaged. Please confirm.

The provision as per bidding specification shall prevail.

59 of 100 Guidelines for Functional Grouping of Controllers

Bidder shall try to adhere to the functional grouping guidelines given by the customer wherever possible. However customer is requested to accept functional grouping as per vendor's standard & proven practices also.

The provision as per bidding specification shall prevail.However, if any specific issues to be reviewed will be done during contract finalisation stage.

6 of 100 Off site system DDCMIS shall be of the same make as BOP.

BOP part of Unit DDCMIS may be of different of different make than plant DDCMIS

The provision as per bidding specification shall prevail.

72 of 85 Performance Calculations (Class I and Class II)

Please note that for each unit ,performance calculations shall be part of DDCMIS and no standalone system shall be considered for this purpose.

The provision as per bidding specification shall prevail.

3 of 100 Software for determination of optimum controller parameters

DDCMIS software , hardware and features shall be offered as per DCS Vendor standard practice. Please confirm acceptance.

The provision as per bidding specification shall prevail.

The Bidder shall provide separate HART system with suitable interface (complete Hardware & software) for each unit DDCMIS Please note that Analysers with HART Protocol shall be provided as per 6 of 100 only for centralized configuration, maintenance, diagnosis & recordmarket availability. Please confirm acceptance. keeping for all electronic transmitters, control valves, analyzers and any other instruments with HART protocol

Confirmed.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

iii. BOP System The balance of plant (BOP) C&I system comprising of ... ...control and monitoring of some offsite system Please note that Air Conditioning system and ventilation system is generally, 5 of 100 plant like CW & ACW system, Cooling Tower, , Air Conditioning supplied by package vendor as per their proven practice and implemented in and ventilation system of Main plant control building area and ESP a proprietary control system. Please confirm acceptance. control building area etc. a

Owner's Reply

The provision as per bidding specification shall prevail.

7

Vol. V: PART A

2.03.01 III

8

Vol. V: PART A

2.04.06

7 of 100 Operator Work Station (OWS) in Unit Control Room (UCR).

As there is no such control room called Unit Control room, we understand, here Unit Control Room refers to Central Control Room. Please confirm.

2.04.13

Wireless Link:-For the following system identified below, Bidder shall consider wireless link or hardwired link for remote operation of the systems: 1. AAQMS system as described in Vol. V, Sub Sec chapter 15, 7 of 100 Part B. 2. Between CHP stacker reclaimer PLC and station LAN switch/CHP DDCMIS as described in Vol. V, Sub Sec chapter 14, Part B.

We propose not to use the wireless link for remote operation of stacker reclaimer. The operation of CHP stacker reclaimer shall be only from its The provision as per respective PLC. Bidder shall envisage a redundant communication link bidding specification shall between Stacker Reclaimer PLC & CHP DDCMIS , CHP DDCMIS & station prevail. LAN/DDCMIS for continuous monitoring. Hence Wireless Link is not required. Please confirm.

9

10

Vol. V: PART A

Vol. V: PART A

2.04.13

Also bidder to include the following i. Bidder shall include all necessary equipments including towers on both sides. ii. All licenses, statutory clearances for equipment in his scope. 7 of 100 iii. The fixed charge and the running cost till warranty period shall be included in the quoted price. iv. All the Coordination, obtaining clearances and payment of applicable fees required for obtaining license in owner’s scope shall be in bidder scope.

1. All Licenses, statutory clearances, co for wireless communication spectrum in the plant shall be obtained by SJVN. Please confirm. 2. We understand that coordination, obtaining clearances and payment of applicable fees required for obtaining license shall be done by SJVN.

Confirmed.

The provision as per bidding specification shall prevail. 1. All Licenses, statutory clearances, co for wireless communication spectrum in the plant shall be obtained by the Biddder. SJVN will help / assist the procedure of obtaining the clearances. 2. Confirmed.

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Section / Part / Chapter / Volume

Vol. V: PART A

Clause No.

2.08.02

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

For each of the non-DDCMIS based controls being provided for any system, 1 set of programming tool/laptop for each such system Programming tool for viewing and changing logic/ program/ setting shall be 8 of 100 shall be provided to view & change logic/program/settings. The integrated within the respective system EWS/HMI and no separate tool shall Bidder shall furnish a comprehensive list of such systems within 6 be provided. Please confirm months of NOA. Control Equipment Room (CER) is envisaged in the same floor i.e. control tower in Main plant building (TG Hall). It shall have various 84 of 100 system cabinets such as BOP DDCMIS cabinets, SG C&I system cabinets, TG C&I system cabinets, vibration monitoring system cabinets, Coal bunker level monitoring unit....

Owner's Reply

The provision as per bidding specification shall prevail.

Coal Bunker Level Monitoring Unit shall be installed in the field at coal bunker The provision as per floor and we shall have 4-20 mA signal in DDCMIS. Based on this Coal bidding specification shall bunker Level monitoring unit will not in Control Equipment Room. Please prevail. confirm.

12

Vol. V: PART A

2.00.00 (2)

13

Part B/Ch 1:General Information and Design Criteria

1.07.01

6 of 100

The control system hardware (controllers, modules/cards etc.) shall be housed in cabinets located in respective control equipment Please note that there shall be only one Control Equipment Room (CER) in 6 of 85 room (CER) unitised and offsite except for the remote I/O cubicles Main plant building. There is no separate room as Control Equipment Room (as specified in Vol.-V, Part-A) which shall be located in respective considered for local control rooms. Please confirm. areas

Confirmed.

Environmental ConditionsIP 32****** With a suitable canopy at the top to prevent ingress of dripping water

Please note that DDCMIS Panels/ PLC panels, TCS/TPS panels, BMS/ BPS panels, Vibrations panels etc. located in air conditioned environment shall not Confirmed. be provided with canopy and the same shall be as per manufacturer's standard. Please accept.

14

Part B/Ch 3: DDCMIS

3.10.04

15

Part B/Ch 3: DDCMIS

3.17.01 (k)

Monitor sensor wire break/open circuit/short circuit and take 8 of 85 suitable actions in logic/loop. (This will include blocking of trip signals in case of RTD failure).

Please note that the features like Monitor Sensor wire break/open circuit/ short circuit shall be as per DDCMIS manufacturer's standard

The provision as per bidding specification shall prevail.

3.20.02 (b)

Triple/dual analog sensors are required both in CLCS and OLCS for control purpose, then all of these triple/dual sensors shall be wired to the controller where CLCS loop is configured. If based on the same set of sensors, any protection action is required in OLCS 11 of 85 (e.g.,protection stop of drive) in another controller(s), then CLCS Controller shall provide three digital outputs for each such controller from three separate output modules (at defined LVMLimit Value Monitor blocks inside controller). The three such digital outputs of CLCS controller shall be acquired in each of the OLCS controllers in three separate digital input modules.

Please note that Controller to controller communication of same system is through soft link. The hardwired signal exchange will be applicable only in case of communication between separate control system with separate controller. Please confirm

The provision as per bidding specification shall prevail.

3.33.06

System cabinet(s) and corresponding marshalling and termination cabinet(s) shall be a single shipping section, so that the internal 35 of 85 wiring from field terminal to the module is done completely at the factory itself.

Packaging of cabinet for shipping shall be as per manufacturer standard practice. Please accept

The provision as per bidding specification shall prevail.

16

17

Part B/Ch 3: DDCMIS

Part B/Ch 3: DDCMIS

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Section / Part / Chapter / Volume

Part B/Ch 3: DDCMIS

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

3.47.03

In addition to above, facility shall be provided to connect 02 nos, remote OWS stations located at Owner’s Headquarter Lucknow through the telephone exchange to retrieve data as specified. The We understand that provision of connection shall be taken care by Bidder , The provision as per Bidder shall provide all necessary software & hardware including however the supply of these PC and connection through telephone exchange bidding specification shall 55 of 85 suitable modems for the connectivity. "ready to plug" ports shall be shall be taken care by Purchaser. Please confirm. prevail. provided for future connectivity of 10 PC stations . Bidder shall arrange to test one such connection through telephone exchange at site The Servers/Workstations/PCs/Laptop to be provided by the Bidder should be latest available in the market at the time of supply to prevent early obsolescence and shall be subject to Owner’s The Servers/ Workstations/ PCs/ Laptop & software package shall be of 61 of 85 approval. The software packages to be included with the latest version available at the time of placement of order. Please confirm. server/OWS/PCs shall also be the latest version available at the time of supply.

19

Part B/Ch 3: DDCMIS

3.49.02

20

Part B/Ch 3: DDCMIS

3.50.00 (x)

69 of 85

Intelligent SNMP manageable mini-UPS for 30 minutes backup shall be provided with all accessories and software.

The provision as per bidding specification shall prevail.

As the Main Plant UPS is considered for all OWS/Server/Programming Confirmed. Stations, separate mini UPS will not be envisaged. Please accept and confirm 1) We understand that Location for installation of AAQMS shall be informed by SJVN. 2) Statutory clearance related to AAQMS shall be arranged by the Bidder, However, any help or assistenace in obtaining the clearnace will be done The provision as per bidding specification shall prevail.

21

Part B/Ch 15: Environment Monitoring Systems

15.02.13

Minimum requirements like input power, space, approach and any other associated facilities required for installation and commissioning of the AAQMS shall be specified by the bidder in 14 of 28 the offer. Installation and commissioning of the AAQMS shall be done by the bidder at the site provided by Owner. Bidder shall obtain statutory and other clearances for purchase, commissioning and operation & maintenance of the AAQMS.

22

Vol. V: PART A

2.04.13

7 of 100

23

Vol. V: PART A

7.04.00

16 of 100 Complete Instrumentation cables shall be armoured

Customer is requested to accept unarmoured cables in indoor location or wherever cable is passing through conduit or on over a cable tray. Bidder shall supply outdoor cable as armoured cable. Customer is requested to accept the same.

24

Vol. V: PART A

3.00.00

42 of 100 Camera shall be provided at every 70 meter distance

Bidder proposes to install cameras at very 100 Mtr distance , as the cameras Confirmed. shall easily cover view of 100 Mtr. Kindly confirm

Wireless Link- Between CHP stacker reclaimer PLC and station LAN switch/CHP DDCMIS

1) We understand that Location for installation of AAQMS shall be informed by SJVN. 2) Statutory clearance related to AAQMS shall be obtained by SJVN and not by vendor/bidder. Please confirm.

Wireless link function is not envisaged in bidder supplied DCS. Please confirm acceptance.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

25

EPC PACKAGE Part B, Chapter 9: Instrumentation Cables

9.02.05

17 of 33

Fiber Optic Cable N. TESTS

Bidder shall furnish the Type Test Certificates for Cables wherever applicable. No tests shall be conducted separately.

The provision as per bidding specification shall prevail.

26

Volume II Ch 9 : Mandatory Spares

1.00.01.12

83 of 106

Ultrasonic type level transmitter 50% of each type and length, including sensors

Bidder Proposes to consider 10% spares of total population for station as Ultrasonic Tx are less prone to fail. Kindly confirm the same.

The provision as per bidding specification shall prevail.

Bidder proposes customer not to take LVS controller as a mandatory spare. Instead customer can take electronic modules required for LVS controller. Customer to kindly confirm. Also there is repetition in Mandatory Spares for LVS required ( Cl. No. 1.00.10.08 and cls. no. 1.00.02.31.14.08). Kindly confirm LVS spares philosophy

The provision as per bidding specification shall prevail.

Requirement of fuses seems to be on much higher side. Customer is requested to take 100% spare fuses. Kindly confirm.

The provision as per bidding specification shall prevail.

27

Ch 9 : Mandatory Spares

28

Ch 9 : Mandatory Spares

29

EPC PACKAGE Part B, Chapter 9: Instrumentation Cables

Bid Specification Stipulation

88 of 1.00.02.31.14.0 106 & 93 LVS Controller of each type for LVS 8 1.00.10.08 of 106

1.00.08.02

9.01.03.11

30

Vol. V: PART A

2.11.00 ( e )

31

Vol. V: PART A

2.06.00

91 of 106

Fuses/Semiconductor Fuses- 300% of installed of each type, current rating with each panel /board

Statement of Prebid Queries & Clarification

Owner's Reply

All type of the cables used for emergency trip push buttons, Fire alarm, detection & protection system, safety critical circuit, trip protection circuit and for other services specified elsewhere in the 4 of 33 specification shall be fire survival cable conforming to IEC 60331, Bidder has envisaged only FRLS cable for all such applications. BS6387 (CWZ), BS6207 standard and this specification. The instrumentation cables in the other area shall be FRLS conforming to IEC 60332 standards and this specification.

The provision as per bidding specification shall prevail.

In case different control system is provided for TG system (refer clause 2.03.02) & it is bidder’s standard and proven practice not to provide separate marshalling cabinets, then the system cabinet 9 of 100 can be suitably partitioned to create separate marshalling area on the rear side of the system cabinet to ensure segregation of the electronic module area from the marshalling area.

For Offsite DDCMIS, separate marshalling cabinets OR suitably partitioned System Cabinet to create separate marshalling area on the rear side of the system cabinet shall be provided as per manufacturer's standard and proven practice

The provision as per bidding specification shall prevail.

In addition to Remote I/O, Remote Controller shall also be provided as finalized during detailed engineering. E.g. Remote Controller along with I/O cabinet

Confirmed.

8 of 100 Remote Input/ Output Modules

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32

Section / Part / Chapter / Volume

Part B/Ch 1: General Information and Design Criteria

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

1.04.01

Bidder shall ensure that various C&I instruments /equipment like vibration monitoring system, 4-20mA electronic transmitters / transducers, Temperature elements and other instruments/ local Bidder will try to minimize the different makes however It is not feasible to Bidder to follow the tender 5 of 10 devices etc. that are being furnished by comply fully with this requirement owing to numerous packages and suppliers specification requirements the bidder, are of the same make, series and family of hardware so involved across the globe. to the extend possible. as to ensure smooth and optimal maintenance, easy interchangeability and efficient spare parts management.

In order to achieve above, following shall be redundant with automatic change-over (including the associated software), as a 4 of 85 minimum: Servers/information work stations

33

Part B/Ch 3: DDCMIS

3.06.04

34

Part B/Ch 2: Field & Measuring Instruments

2.09.01

35

Vol. V: PART A

7.03.00

36

Part B/Ch 11: Control Valves With Actuators

11.06.00

37

Vol. V: PART A

4.00.00 (g)

Common Requirements for all Analysers:16 of 63 8. Calibration: Auto & Manual (from Remote)

Separate cables are to be provided for dual / triple redundant 16 of 100 instruments used for protection of Unit and HT drives. These cables are also to be laid in separate routes to the extent feasible.

5 of 9

All control valves shall be furnished with pneumatic actuators except for pressure and temperature control valve for auxiliary PRDS application (Electro-hydraulic / pneumatically operated) and separator drain control valve (Electro-hydraulic type)

MEASURING INSTRUMENTS (PRIMARY AND SECONDARY)12 of 100 Redundancy requirements/Criteria for Sensors & Signals from MCC/SWGR

For the server based DDCMIS Architecture, redundant servers shall be provided. However, for server less Architecture (station based systems), quantity of operator work stations shall be provided as per tender, such that single point failure shall not affect the operation of plant. However, redundancy in Historian station / Station LAN Server/ Programming station shall be provided as per tender requirements

The provision as per bidding specification shall prevail.

Auto calibration of pH & Conductivity analyzer is not available and same shall Bidder to provide as per be provided as per manufacturer's standard design. Specification requirements.

Bidder will route the cables as per our standard practice. It is not feasible to lay the cables separately for dual / triple redundant instruments used for protection of Unit and HT drives.

The provision as per bidding specification shall prevail.However, if any specific issues to be reviewed will be done during contract finalisation

Bidder clarifies that the type of actuator for control valve will be as per sizing requirement

The provision as per bidding specification shall prevail.

Redundancy requirements will be considered as per standard OEM practice

The provision as per bidding specification shall prevail.

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38

39

40

41

Section / Part / Chapter / Volume

Clause No.

Part B, Chapter 4 : Main Equipment Related C&I system

4.13.00

Vol. V: PART A

3.00.00 (j)

Part B/Ch 8: PROCESS CONNECTION AND PIPING

8.01.02

Part B/Ch 8: PROCESS CONNECTION AND PIPING

Table 8.1

Part B/Ch 15: Environment Monitoring Systems

15.01.03 (14)

Vol. V: PART A

2.04.11

Page no.

Bid Specification Stipulation

The system shall utilize non sampling/extraction type microwave technology for online monitoring/measurement of the unburnt 10 of 23 carbon in fly ash with minimum 4 nos. probes measurement to have complete profile per location. The system shall measure a fly ash at a representative location

Statement of Prebid Queries & Clarification

Owner's Reply

As this is not a proven system in the Indian power plant, the same is not considered by bidder.

The provision as per bidding specification shall prevail.

All the impulse piping and fittings in boiler will be of SS316 as OEM standard practice

The provision as per bidding specification shall prevail.

Please note that sample handling system shall be sourced from approved local sub vendors of original analyzer manufacturer (OAM).

The provision as per bidding specification shall prevail.

10 of 100 On Line Carbon in Ash Analysers System All impulse pipes shall be of seamless type conforming to ANSI B36.10 for schedule numbers, sizes and dimensions etc. The size of impulse pipe shall be ½” for steam and water applications and 2 of 10 ¾” for air and flue gas applications. The material of impulse pipe shall be same as that of main process pipe. For various applications specification of impulse pipe material and associated fittings and valves shall be as given in table PCP.

9 of 10 Technical Specifications for C&I Systems-Table-No. 8.1 For Hot-extractive sampling type and Dilution extractive type systems, the entire system including analysers, sample handling/conditioning system etc 5 of 28 offered shall be sourced from/assembled at Original Analyser manufacturer(OAM) works i.e., all components involved shall be imported or sourced from OAM only and no indigenous component shall be used.

Redundant LAN for communication between various OWS, between OWS and processing stations and OWS/PC. A redundant station-wide LAN for connecting the unit and other sub systems of DDCMIS, PLCs, as applicable OWS, stations & DMS etc. as well SJVN shall provide communication media/ISDN facility including all cables, 7 of 100 for connecting to the other off-line services of the Station LAN This hardware and software for establishing connectivity from powerhouse to shall include all cables, hardware, software and accessories remote terminals at Headquarter. required for connecting Bidder’s system up to the remote terminals at Headquarters in Lucknow. Complete system interfacing & successful implementation is in bidder’s scope.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Part B/Ch 3: DDCMIS

43

Part B/Ch 14: Annexure-A Control System for BOP/Offsite packages

44

Part B/Ch 7: UPS & 24 V DC System

7.01.01.02

2 of 21

45

Part B/Ch 7: UPS & 24 V DC System

7.01.01.03

2 of 21

46

Vol. V: PART A

G2

45 of 100

24.e

25 of 106

47

Ch 9:Mandatory Spares

16.2

30 of 106

48

6 of 10

20.03.00 (1)

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

The provision as per bidding specification shall prevail.However, if any Bidder shall provide integrated HART Management System; Please confirm. specific issues to be reviewed will be done during contract finalisation stage. Bidder understanding is correct . Bidder to meet System / Package :Hydrogen Generation Plant PLC based control system shall be provided as per OEM standard practice. the Specification Control System: BOP HG DCS requirements, functionalities etc. The provision as per Further, Bidder shall supply separate parallel redundant industrial bidding specification shall grade Uninterruptible Power Supply (UPS) System for each prevail.However, if any Systems such as CMMS,PSSS,Simulator,Station LAN etc. shall be fed from independent BOP packages C&I equipments / items such as BOPspecific issues to be common UPS DCS, PLCs, Field Instruments, Solenoid valves, PSSS, Simulator, reviewed will be done CMIMS, MIS, Station LAN, Service Building, C&I Lab. during contract finalisation stage. Since various BOP packages are supplied by different vendors/OEMs, it is The provision as per ALL UPS systems for the Main plant as well as for BOP off site not possible to maintain same make UPS across the plant. However Bidder bidding specification shall packages and for other C&I packages shall be of the same Make. shall try to maintain same make of UPS to the extent possible. prevail. Bidder clarification Bidder requests SJVN to review the ranges provided for CEMS analysers, as Agreed. Will be finalised LIST OF CEMS ANALYSERS PER UNIT these ranges are applicable when FGD is not in operation. during contract finalisataion stage . Turbine Driven Boiler Feed Pump Since Accessories for TDBFP recirculation valves are already included in The provision as per Recirculation control valve complete assemblies:1 Set Mandatory Spares List, Complete Valve Assembly as mentioned in point 24.e bidding specification shall BFP recirculation valve spares is not required and hence shall not be considered. prevail.

The Bidder shall provide a dedicated and standalone WORK STATIONS based HART system with suitable interface for main plant DDCMIS for centralised configuration, maintenance, 50 of 85 diagnostics & record-keeping for all electronic transmitters, temperature transmitters, control valves position transmitters and analysers (as applicable) with HART protocol.

42

Part B/Ch 20: Documentation Management System

3.45.00

Page no.

Bidder should submit the documentary evidence for supplying the Sheet 2 Documentation Management system to at least two industrial of 7 plants/power projects, who have been using the software for a minimum period of two years as on date of opening of bids.

Bidder Requests Customer to revise the Criteria as below; Bidder should submit the documentary evidence for supplying the Documentation Management system to at least one industrial plants/power projects, who have been using the software for a minimum period of two years as on date of opening of bids.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

49

Part B/Ch-19 Operator Training Simulator

50

Part B/Ch 6: Supervisory Control Panels, Supervisory control Desks, Equipment Panels

51

52

Part B/Ch 15: Environment Monitoring Systems

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

19.03.00

The Simulator’s vendor should be a Simulator manufacturer and a graphical user interface (GUI) based simulation modeling tool developer for coal fired thermal power plant and should have 2 of 25 designed engineered, supplied, erected & commissioned full scope replica Training Simulator for a coal fired station having unit size 500 MW or above in India, which is in successful operation for a period of not less than one (1) year as on the date of bid opening.

Bidder Requests Customer to revise the Criteria as below; The Simulator’s vendor should be a Simulator manufacturer and a graphical The provision as per user interface (GUI) based simulation modeling tool developer for coal fired thermal power plant and should have designed engineered, supplied, erected bidding specification shall & commissioned full scope replica Training Simulator for a coal fired station prevail. having unit size 500 MW or above, which is in successful operation for a period of not less than one (1) year as on the date of bid opening.

6.20.00

The bidder shall be reputed and have already executed at least three (3) super critical power plant control Rooms in India. The bidder shall have 3-D software 15 of 25 for designing the control room layouts. The bidder shall have thorough knowledge on Indian power plant control room requirements.

Bidder Requests Customer to revise the Criteria as below; The bidder shall be reputed and have already executed at least one (1) super The provision as per critical power plant control Room. The bidder shall have 3-D software for bidding specification shall designing the control room layouts. prevail. The bidder shall have thorough knowledge on Indian power plant control room requirements.

15.02.27

The analysers must function properly in Indian conditions without Since analyesers are located in Air-conditioned area , requirements of this 18 of 28 any defect between 0 to 50 deg C ambient temperature, 0 to 100% clause is not applicable. relative humidity and in high ambient dust level. For Boiler and Turbine, OEM's standard proven practices for instrumentation and controls shall be followed.

Volume V

Kindly, confirm this understanding.

53

54

Volume V, Part A, 1.0

Volume V, Part A, 1.0

Volume V, Part A, 1.0

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

2.04.11

Redundant LAN for communication between various OWS, between OWS and processing stations and OWS/PC. A redundant 7 of 100 station-wide LAN for connecting the unit and other sub systems of DDCMIS, PLCs, as applicable OWS, stations & DMS etc. as well for connecting to the other off-line services of the Station LAN.

DDCMIS data bus network and PLC data bus network are separate networks. PLC is connected to DCS via hardwired signals for control and soft The provision as per link for monitoring. bidding specification shall prevail. Kindly, confirm this understanding.

2.11.00 (b)

In case Bidder’s system design requires the termination cabinet independent from system cabinet, the marshalling cabinets can be 9 of 100 combined with the termination cabinet. In case, the termination arrangement is part of the system cabinet, independent marshalling cabinets shall be provided.

Marshalling cabinets are not mandatory. Field cables can be terminated directly on DDCMIS/ PLC cards as per DCS Supplier's standard proven practice.

3.00.00 (h)

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. Per ASME TDP-1, either level switches or level transmitters are acceptable.

55

Owner's Reply

10 of 100 Level switches Drip legs employing conductivity type probes Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

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56

Section / Part / Chapter / Volume

Volume V, Part A, 1.0

Clause No.

Page no.

3.00.00 (k)

Turbine supervisory system (TSS) including vibration analyzers, vibration monitoring system, axial shift, eccentricity measurement Bearing vibration measurements, axial displacement, and key-phasor are system etc. for Main Turbine and BFP Turbine etc. Hardware and only applicable to BFP Turbine as per OEM's standard proven practice. 10 of 100 software provisions for diagnosis and analysis of plant auxiliaries vibration as indicated under Appendix-I to Part-A, Vol. V, “Contract Kindly, confirm this understanding. Quantities other than DDCMIS item”

The provision as per bidding specification shall prevail.

Complete hardware and software system for turbine stress This is not applicable for BFP Turbine as per OEM's standard proven computation, fatigue analysis for all affected critical components of practice. 10 of 100 the turbine, computation of Residual Life Analysis and long term storage of the Kindly, confirm this understanding. relevant monitoring of turbine critical components.

The provision as per bidding specification shall prevail.

57

Volume V, Part A, 1.0

3.00.00 (l)

58

1. Volume V, Part A, 1.0 2. Volume V, Part B, Chapter 2

1. 4.00.00 (e) 2. 2.07.00 (a)

59

60

61

Volume V, Part A, 1.0

Volume V, Part A, 1.0

Volume V, Part A, 1.0

4.00.00 (f)

Bid Specification Stipulation

1. 11 of 1. Rail mounted/ Rack mounted temperature transmitters to be 100 provided. 2. 13 of 2. Single Input Head mounted Temperature Transmitter 63 Wherever process actuated switches are being provided for sequence, protection and alarm purposes, adequate number of blind type switches separate for each application ( i.e. sequence, 12 of 100 protection, alarm ) with separate necessary indicating gauges are to be provided meeting adequate redundancy requirements. Contacts of indicating type switches, gauges and receiver instruments shall not be acceptable.

Dual position transmitters shall be provided for Steam Admission Valves i.e. (Main steam Stop & Control Valves, Reheat Stop 4.00.00 (g), (ii) 14 of 100 Valves & Control valves and TDBFP steam stop valves & control valves). 4.00.00 (g), (iv) 14 of 100 No redundant instrument shall share a single process tapping.

Statement of Prebid Queries & Clarification

Head mounted temperature transmitters with suitable nipple extension per application shall be provided in general as per proven standard industry practice.

Owner's Reply

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

This is not applicable for packages like Vacuum Pump skids, BFP Turbine, On Line Tube Cleaning; where OEM's standard proven practice shall follow. Kindly, confirm this understanding.

Turbine and BFP Turbine OEM's standard proven practice shall follow. Kindly, confirm this understanding. Except for redundant DP measurement taps on orifice in pipelines with ≤ 2" diameter due to non availability of space for proper oriented taps. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Bid Specification Stipulation

Volume V, Part A, 1.0

63

For measurement of level of tanks/vessels/sumps containing oil, Volume V, Part A, 1.0 4.00.00 Notes 6 15 of 100 chemicals or water, Ultrasonic type level transmitters shall be provided.

Volume V, Part A, 1.0

4.00.00 Notes 10

Statement of Prebid Queries & Clarification

Wall mounted/panel mounted Digital Display unit /Indicator shall be provided for Main steam pressure, temperature, Fuel flow, CCR LVS graphic screen footer will have permanent display for these Generator load, MW export, MVAR, frequency, Turbine speed, parameters as a standard industry practice. No separate display is required. 14 of 100 Condenser vacuum for unit control room, off-site control rooms and service building as a minimum, and as decided during detailed Kindly, confirm this understanding. engineering stage.

62

64

4.00.00 (i)

Page no.

15 of 100 DPG, DPT & DPS across the filters/strainers shall be provided

For water services, DP type level measurements shall also be acceptable as per standard proven industrial practice. Kindly, confirm this understanding. LCD display type DPT if provided shall suffice, and separate DPS/ DPI shall not be required. Kindly, confirm this understanding.

65

66

67

1. Volume V, Part A, 1.0 2. Volume V, Part A, Appendix-V

Volume V, Part A, 1.0

Volume V, Part A, 1.0

1. 4.00.00 Notes 12 2. 3.00.00 Viii)

6.02.00

7.03.00

1. 15 of 100 2. 96 of 100

1. Thermocouples shall be provided for Mill RTDs shall be usable up to 450°C services as per standard proven industrial outlet temperature and for Services with Temperature > 200 deg C. practice. 2. Thermocouples for Temp. above 200 deg C shall be provided by bidder. Kindly, confirm this understanding.

All transmitters, switches etc. in Boiler Turbine Generator measurements (except for all fuel oil applications) shall be suitably In case of open areas, Local Instrument Racks with canopy/ sunshade shall be acceptable for all instruments having IP65 or higher protection class. grouped together and mounted inside (i) Local Instruments 16 of 100 Enclosures (LIEs) in case of open areas of the plant like boiler Kindly, confirm this understanding. area, etc. and (ii) In Local Instrument Racks (LIRs) in case of covered areas like Turbine/Generator area.

16 of 100

Separate cables are to be provided for dual / triple redundant instruments used for protection of Unit and HT drives.

For triple redundant instruments (say A, B, C) used for protection of Unit and HT drives, 1st cable will contain signals for 2 instruments (say A & B) and 2nd cable will contain signal for the 3rd instrument (say C).

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

68

Volume V, Part A, 1.0

7.04.00

16 of 100 Complete Instrumentation cables shall be armoured

Cable that are protected by routing them in trays, conduits can be unarmoured. Direct buried cables without any protection shall only be armoured The provision as per for protection. bidding specification shall prevail. Kindly, confirm this understanding.

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69

Section / Part / Chapter / Volume

Volume V, Part A, 1.0

Clause No.

7.05.00

Page no.

Bid Specification Stipulation

Heat resistant instrumentation cable shall be provided for all instruments / equipments/ drives / devices located in hot areas such as Burner tilt, Hot air gates, Air heater areas, Furnace areas, Steam Drain & Vent valves, Turbine & Generator zone etc. This 16 of 100 cable shall be laid from instruments / equipments / drives / devices from hot area application to a field JB / panel located in areas where ambient temperature is around 50 Deg. C. i.e. normal temperature area.

Statement of Prebid Queries & Clarification

Owner's Reply

For services where instrument head/ transmitter is located in normal temperature area (i.e. below transmitter design temperature), heat resistant cables are not applicable. For example, the devices of Hot air gates, Air Heater areas, Furnace areas, Steam Drain & Vent Valves, etc will be placed in areas where ambient temperature is below 50 Deg. C, hence Heat Resistant cable is not envisaged.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

70

71

72

Volume V, Part A, 1.0

Volume V, Part A, 1.0

Volume V, Part A, 2.0

Unitwise OWS based stations for display of information and alarm to operator to be located at SWAS room (through station LAN).

13.05.00

18 of 100

13.05.00

Provision of spare parts for at least 15 (Fifteen) years after 18 of 100 commissioning of the plant.

Appendix-I, 7

For SOE signals generated within control system, item “ SOE (Calculated) of Table in case the bidder’s system cannot use the internally 23 of 100 calculated points for SOE monitoring, additional one no. Digital Output and one no. SOE input per SOE point, shall be provided within quoted price.

Display is available in all the analyzers for monitoring SWAS measurements. Also, each sample's pressure/ temperature/ flow gauges are available for local monitoring. OWS in local is not recommended from operation management stand. Kindly, confirm this understanding. Provision of spare parts for at least up to warrantee period. Kindly, confirm this understanding. Internally calculated signals identified for logging purpose are event logged inside DDCMIS as per controller's execution clock frequency, and can be available for event analysis. SOE cards are not applicable for such internal event logging.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. We understand EDMS and EMS as Grid side Switchyard control system, outside Bidder's scope. Only I/O Interface from EDMS/ EMS to DDCMIS is to be considered for load control related minimal signals.

73

Volume V, Part A, 2.0

Electrical I/Os required as per Energy Distribution Management System (EDMS), Energy Management System (EMS), Station Appendix-I, 24 of 100 Electrical system and any other electrical system shall also be Annexure-I, (iv) considered/included by bidder in respective package I/O list.

Further, control, measurement & monitoring of Electrical systems i.e. Gas Insulated Substation, Power Transformers/reactor, MV and LV Switchgears, EDG, DC & UPS System etc. shall be as per requirement mentioned in the respective electrical section only.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

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Section / Part / Chapter / Volume

Volume V, Part A, 2.0

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

In order to increase the availability of a process system, it is recommended that the complete process system shall be assigned to a single controller (which are dual hot redundant), instead of splitting the system in multiple controllers connected via data highway as that will increase the overall The control system shall be functionally distributed, (For Boiler, TG probability of failure of the process system due to increased number of and BOP and similarly the control for 2 similar equipments like ID elements in the overall process system. Appendix-I, 25 of 100 Fan A, B and C should be in different controllers & I/O cards) For example, entire condensate system (i.e. both CEPs, suction tank and Annexure-I, (iv) highly modular and arranged to reflect the functional grouping plant piping instrumentation, discharge header system) shall be assigned to same equipment and systems to be controlled. DDCMIS dual hot redundant controller, instead of breaking the condensate system into 3 controllers.

Owner's Reply

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

75

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

1. Appendix-I, Table "Drive I/O's" 2. TD-12

1. 26 of 100 Actuator Interface (MOV) 2. TD-12

"Actuator Ready" digital input will be wired to DDCMIS/PLC; which will internally comprise of Actuator Remote & Actuator Disturbance Not. It provides the same information status to operator. Hence, MOV actuator will have 2 DO (Open/ close commands) and 3 DI (Open/Close/ Actuator Ready) interface with DDCMIS/PLC. For modulating type MOV, position feedback AI will be additional interface to DDCMIS/PLC.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

76

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

1. Appendix-I, Table "Drive I/O's" 2. TD-17

1. 26 of 100 LT MCC Motor Interface 2. TD-17

Maintained type "Run Command" digital output will be wired from MCC motor starter to DDCMIS/PLC. Similarly, maintained type "Run Feedback" DI will be wired to DDCMIS. It provides the same information status to operator. The provision as per Hence, MCC Motor will have 1 DO (Run command) and 3 DI (Run/ Ready/ bidding specification shall Trip) interface with DDCMIS/PLC. prevail. Kindly, confirm this understanding.

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Section / Part / Chapter / Volume

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

Clause No.

1. Appendix-I, Table "Drive I/O's" 2. TD-22/23

Page no.

Bid Specification Stipulation

1. 26 of 100 LT SWGR Interface 2. TD22/23

Statement of Prebid Queries & Clarification

Owner's Reply

"Breaker Ready" digital input will be wired to DDCMIS/PLC; which will internally comprise of SWGR Available & SWGR Disturbance Not. It provides the same information status to operator. The provision as per Hence, LT SWGR Breaker will have 2 DO (Open/ close commands) and 4 DI bidding specification shall (Open/Close/ Breaker Ready/ Breaker Tripped) interface with DDCMIS/PLC. prevail. Kindly, confirm this understanding.

78

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

1. Appendix-I, Table "Drive I/O's" 2. TD-19

1. 26 of 100 HT SWGR Motor Interface 2. TD-19

"Breaker Ready" digital input will be wired to DDCMIS/PLC; which will internally comprise of SWGR Available & SWGR Disturbance Not. It provides the same information status to operator. "Breaker Tripped" digital input will be wired to DDCMIS/PLC; which will internally comprise of Electrical Protection Operated & SWGR EPB The provision as per Operated. It provides the same information status to operator. bidding specification shall Hence, HT SWGR Motor Breaker will have 2 DO (Open/ close commands) prevail. and 4 DI (Open/Close/ Breaker Ready/ Breaker Tripped) interface with DDCMIS/PLC. Kindly, confirm this understanding.

79

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

1. Appendix-I, Table "Drive I/O's" 2. TD-24/25

1. 26 of 100 HT SWGR Interface 2. TD24/25

"Breaker Ready" digital input will be wired to DDCMIS/PLC; which will internally comprise of SWGR Available & SWGR Disturbance Not. It provides the same information status to operator. The provision as per Hence, HT SWGR Breaker will have 2 DO (Open/ close commands) and 4 DI bidding specification shall (Open/Close/ Breaker Ready/ Breaker Tripped) interface with DDCMIS/PLC. prevail. Kindly, confirm this understanding.

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80

Section / Part / Chapter / Volume

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

Clause No.

1. Appendix-I, Table "Drive I/O's" 2. TD-20/21

Page no.

Bid Specification Stipulation

1. 26 of 100 SOV Interface 2. TD20/21

Statement of Prebid Queries & Clarification

Owner's Reply

SOV will have 1 DO (command) and 2 DI (Open/Close) interface with DDCMIS/PLC. The provision as per Double SOV will have 2 DO (Open/ close commands) and 2 DI (Open/Close) bidding specification shall interface with DDCMIS/PLC. prevail. Kindly, confirm this understanding.

81

82

1. Volume V, Part A, 2.0 2. Volume VII, C&I TD

Volume V, Part A

1. Appendix-I, Table "Drive I/O's" 2. TD-15

Appendix-I, Table "Drive I/O's"

1. 26 of 100 Control Valve (CV) Interface 2. TD-15

26 of 100

Drive I/Os quantity

CV will have 1 AO (command) and 1 AI (position) interface with DDCMIS/PLC. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

This table in tender does not define the abbreviation of each type of the drive and the description of each of the signal quantity considered. Bidder's above clarifications cover all the drive types and their interface The provision as per signal quantity with DDCMIS/ PLC. Any new drive type interface required bidding specification shall during execution phase shall be in similar philosophy, and will be submitted prevail. to Client for approval during execution phase. Kindly, confirm this understanding.

Redundancy in binary outputs for OLCS drives: Station C&I DDCMIS System: For 20% of drives distributed in various functional groups (Exact application shall be finalized during detailed engineering.) 83

84

Volume V, Part A

Volume V, Part A

Appendix-I, 23 of 100 Notes-2 and 3 Redundancy in analog outputs for CLCS drives: Station C&I DDCMIS System: For 40% of drives distributed in various functional groups (Exact application shall be finalized during detailed engineering.) Appendix-I, 2.3, 43 of 100 Closed circuit CW (TG & SG): pH, Specific Conductivity F

Redundancy in DO or AO in station C&I shall be applied only if the equipment trip results in loss of plant MW or human life (double failures are not considered in design as per standard industrial design practice) as approved The provision as per during detailed engineering, but in no case the quantity of redundant DO bidding specification shall shall be higher than 20% of total DO and quantity of redundant AO shall be prevail. higher than 40% of total AO. Kindly, confirm this understanding. DM water is filled in CCW and specific conductivity analyser suffices for any contamination monitoring. pH is not required. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

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85

86

87

88

89

90

Section / Part / Chapter / Volume

Volume V, Part A

Volume V, Part A

Volume V, Part A

Volume V, Part A

Volume V, Part B, Chapter 5

Volume V, Part A, Appendix-V

Clause No.

Page no.

Bid Specification Stipulation

Appendix-I, 2.3, 43 of 100 Deaerator: Silica, pH, Dissolved Oxygen F

Condenser Tube Leak detection at each inlet & outlet CW line: Cation Conductivity (Insertion /Retractable Type) Appendix-I, 2.3, 43 of 100 Alternatively Cation Conductivity analyser shall be doubled at CEP F discharge.

Appendix-I, 2.3, 43 of 100 F Triple and Dual analysers shall be provided for Appendix-I, 2.3, 43 of 100 DM Plant Controls and chemical/O2 dosing F controls.

5.01.03

6.00.00

The SWAS panels shall comprise of two panels viz. Sample Conditioning Panel and Analyser Panel located in centralized 2 of 17 SWAS room. All the SWAS panels shall be located in air conditioned area

100 of 100

Wherever transmitters & switches are provided, in addition Local gauges shall also be provided by bidder for local field monitoring.

Statement of Prebid Queries & Clarification

DO analyser will be provided at deaerator outlet. Silica & pH analyser is provided at Economiser inlet (i.e. deaerator outlet BFP discharge water), and The provision as per hence these are not required at deaerator outlet. bidding specification shall prevail. Kindly, confirm this understanding. CC analyser sample needs to be passed through cat-ion exchange column and hence insertion/ retractable type is not applicable. Specific conductivity insertion type is feasible and will be provided in hot well (one on each side).

Volume V, Part B, Chapter 11

11.02.03

2 of 9

Thus for cavitation/flashing service, only valve with anti cavitations trim shall be provided.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. Dual channel analysers shall be provided for pH, SC, CC, DO as a standard industry practice. Kindly, confirm this understanding. There is no plant Trip interlock on SWAS parameters and hence, triple or dual redundancy of analysers is not applicable. Kindly, confirm this understanding. Sample conditioning panel & chiller of SWAS is wet panel, and it does not need air conditioning ambient. Hence air conditioning will not be provided for them. Glass partition shall be provided between the wet panel and dry panel.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. Wherever LCD display type transmitters are provided for local field monitoring, separate local gauge shall not be required. Kindly, confirm this understanding.

91

Owner's Reply

Anti-cavitation trims are not applicable for flashing services. Rather, hardened trims are applicable. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

92

Volume V, Part B, Chapter 11

93

Volume V, Part B, Chapter 11

Clause No.

11.02.06, 11.02.07

11.04.00

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

3 of 9

11.02.07 The Liquid pressure recovery factor (FL) shall be 0.995 or better for severe flashing/cavitation services. Feed Water Control Valve, Super heater & Reheater Spray Water Control FL value shall be as per valve manufacturer and would be typically 0.9 or valves, LP/HP heater emergency & normal level control valve, HP better in such services. /LP BP control valves, HP /LP BP spray control valves, Deaerator Overflow control valve and Separator Drain level control valve shall Kindly, confirm this understanding. be considered for Severe Flashing/ cavitations service by bidder. 11.02.07 The Liquid pressure recovery factor (FL) shall be 0.985 or better for low flashing/cavitation services.

4 of 9

Non-corrosive, non-flashing, and non- cavitation service for process temperature up to 275 Deg C.: Trim Material = 316SS stellited with stellited faced guide posts and bushings

For Non-corrosive, non-flashing, and non- cavitation service, and which are far from cavitation zone, SS316 trim material shall suffice, and stellited coating is not required.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

94

Volume V, Part B, Chapter 11

11.06.00

6 of 9

The travel time of the pneumatic actuators shall not exceed 10 seconds

Travel time shall be as per the process control requirements. For slow moving processes, control valve travel times of 20sec shall also be acceptable.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

95

96

Volume V, Part B, Chapter 11

Volume V, Part B, Chapter 9

11.07.02

9.01.03.05

6 of 9

Separate moisture separator unit for ensuring dryness of air entering I/P as well as the power cylinder is to be supplied with each control valve and control damper.

All type of the cables used for emergency trip push buttons, Fire alarm, detection & protection system, safety critical circuit, trip protection circuit and for other services specified elsewhere in the 3 of 33 specification shall be fire survival cable conforming to IEC 60331, BS6387 (CWZ), BS6207 standard and this specification. The instrumentation cables in the other area shall be FRLS conforming to IEC 60332 standards and this specification.

Dry Instrument Air is supplied to each control valve. Hence, separate moisture separate is not applicable. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

Fail safe contacts and fail safe interlocks on bad value analog signals (i.e. trip will actuate in case of power failure or cable cut) are used for Emergency trip The provision as per push buttons, safety critical circuit, and trip protection circuit, hence FRLS bidding specification shall type cables shall be used without the need of fire survival cables. prevail. Kindly, confirm this understanding.

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Section / Part / Chapter / Volume

Volume V, Part B, Chapter 9

Clause No.

9.01.03.13

Page no.

4 of 33

Bid Specification Stipulation

All cables shall be paired cables with voltage grade rating of 660/1100V.

Statement of Prebid Queries & Clarification

Owner's Reply

Since Instrumentation cables are applied for low voltage system (like < 60V circuits), so as per BS 5308 standard, the insulation of instrumentation cables The provision as per shall be suitable for operation at voltages up to 300Vrms core to earth and bidding specification shall 500Vrms core to core. Same shall be applied. prevail. Kindly, confirm this understanding.

98

99

100

101

Volume V, Part B, Chapter 9

Volume V, Part B, Chapter 9

Volume V, Part B, Chapter 9

Volume V, Part B, Chapter 9

9.01.03.16

a) Cables for analog signals shall be instrumentation paired cable of 0.5 sq. mm copper conductor size, with individual pair shielding & over all shielding as per cl. No. 9.02.02 mentioned below. 5 of 33 b) Cables for binary signals shall be instrumentation paired cable of 0.5 sq. mm copper conductor size as per cl. No. 9.02.02 mentioned below with over all shielding only.

It shall be acceptable to combine digital signals in analog multi-pair cable, as both are low voltage circuits (< 60V) and analog cable meets/exceeds the requirements of digital cable.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

9.02.05

Distance limitation is a function of data rate. Multimode FO cables have been Multimode fiber optic cables shall be used for shorter distance. For used up to 2000m for 100mbps data rates as a standard proven industrial The provision as per 13 of 33 large distance i.e. more than 500 meter of single run, single mode practice. bidding specification shall Fiber optic cables shall be used. prevail. Kindly, confirm this understanding.

9.03.03

All wiring leaving a junction box or enclosure shall leave from terminal blocks and not from other devices in the enclosure.

TBs inside enclosure/ racks are not applicable as each instrument head has a dedicated cable entry, and this would reduce a un-necessary break junction The provision as per point in the cable circuit. bidding specification shall prevail. Kindly, confirm this understanding.

Optical fiber cables (OFCs): Inside Building Area – to be laid on separate cable sub-trays

Optical cables have no signal interference issues with instrumentation cables and no operating temperature issues (instrumentation cables are low voltage The provision as per circuits). Hence, OFCs can be laid in instrumentation cable trays. bidding specification shall prevail. Kindly, confirm this understanding.

9.07.00

21 of 33

24 of 33

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102

103

104

105

Section / Part / Chapter / Volume

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 3

Clause No.

3.07.00

Page no.

Bid Specification Stipulation

In case a controller utilizes some inputs generated/processed by any other controller/functional group and the requirement of controller response time is not met due to inadequate 5 of 85 communication rate/procedure, then hardwired signal exchange shall be provided for such inputs. Control & protection signal exchange between any functional groups controllers and sub systems shall be hardwired only.

3.08.07

Twenty(20) percent spare relays wired of each type and rating, mounted and wired in relay cabinets terminal blocks of relay 5 of 85 cabinets. In each of the relay cabinets, 10 % spare terminal blocks shall be provided so that additional relays can be mounted and wired

3.19.03

The sensors for multiple measurement schemes for open loop controls shall always be in service (except when gone Bad) and 10 of 85 operator shall not be able to select / deselect any of the sensors. Further, measurement scheme shall be implemented considering safety / availability aspects.

3.20.02

a. The on-off status of HT drives and synch type breakers shall be 11 of 85 wired to two input modules in parallel.

Statement of Prebid Queries & Clarification

Controller and control bus spare capacities as per contract are already ensured, and also the control bus is redundant. Hence, any signal interface required between controllers shall be through the reliable control bus only.

Owner's Reply

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

As per Volume VII C&I TD wiring drawings, and Volume V Part A, interposing relays are part of SWGR/ MCC. Spare clause are not applicable for these The provision as per relays which are not part of DCS panels. bidding specification shall prevail. Kindly, confirm this understanding.

This shall be applied only for triple redundant measurements which are used in critical/ safety applications. Kindly, confirm this understanding.

As per Volume V Part A, redundancy for DI modules is not applicable. Only one DI will be wired for Open & Close feedbacks from HT drive breaker. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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106

107

108

109

Section / Part / Chapter / Volume

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 2

Clause No.

3.20.02

3.30.05

3.52.01

2.01.01

Page no.

Bid Specification Stipulation

b. Triple/dual analog sensors are required both in CLCS and OLCS for control purpose, then all of these triple/dual sensors shall be wired to the controller where CLCS loop is configured. If based on the same set of sensors, any protection action is required in OLCS (e.g., protection stop of drive) in another controller(s), then CLCS Controller shall provide three digital outputs for each such controller from three separate output modules (at defined LVMLimit Value Monitor blocks inside Controller). The three such digital outputs of CLCS controller shall be acquired in each of the OLCS controllers in three separate digital input modules. Similar philosophy will be used 11 of 85 when triple/dual analog sensors are required in OLCS in multiple controllers for protection function. c. If triple/dual/single binary sensors are required in OLCS in multiple controllers for protection function in these controllers, each of these sensors shall be shared among these controllers. Each of these sensors shall be directly shared from marshalling TBs without any ‘active’ multiplying hardware (‘active’ defined as hardware which requires a separate power supply for its functioning). Further, removal/insertion of any of such multiple modules shall not affect availability of such signal(s) to other modules.

11 of 85

The redundant buses shall be physically separate and shall be routed separately.

Statement of Prebid Queries & Clarification

Controller and control bus spare capacities as per contract are already ensured, and also the control bus is redundant. Hence, any signal interface required between controllers shall be through the reliable control bus only.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

As per Volume V Part A, redundant buses shall be routed on separate routes to the extent feasible. The provision as per Also, consider partitioned or separate trays or conduits within trays as bidding specification shall separate route. prevail.

Kindly, confirm this understanding. PID tuning is part of commissioning activity and will be done by Bidder's The programming station shall be equipped with a system/software personnel. Once PID is tuned and plant handed over then, parameters are to calculate the tuning constants i.e. P, I and D values of control not required to be adjusted. So, auto tuner feature shall not be mandatory. 72 of 85 loops automatically. Kindly, confirm this understanding. ELECTRONIC TRANSMITTER FOR PRESSURE, DIFF. PRESSURE AND DP BASED FLOW, LEVEL MEASUREMENTS Turn down ratio: 3 of 63 30:1 for vacuum/very low pressure applications. 10:1 for very high pressure application. 100:1 for other applications

Owner's Reply

Bidder understands as below: 100:1 turndown is for DP transmitters 30:1 and 10:1 are for Pressure transmitters

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding.

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Section / Part / Chapter / Volume

110

Volume V, Part B, Chapter 2

9, 11 of Sheath O D 8 mm 2.06.01, 2.06.02 63

111

Volume V, Part B, Chapter 2

2.06.01, 2.06.02

112

Volume V, Part B, Chapter 2

Clause No.

2.10.00

Page no.

Bid Specification Stipulation

Extension neck length: Minimum 100 mm above 9, 11 of Insulation of pipe and Minimum 160 mm when there is no 63 insulation on pipe.

Statement of Prebid Queries & Clarification

Owner's Reply

Thermocouple are tip sensing device and RTD are length sensitive device. Sheath OD of 6mm is also proven and widely used in industry. Same shall be The provision as per acceptable. bidding specification shall prevail. Kindly, confirm this understanding. When there is no insulation, it means it’s a low temperature service. So, 100mm extension length is enough per typical industry practice to keep The provision as per instrument head temperature low. bidding specification shall prevail. Kindly, confirm this understanding.

Alternative to 4-20mA wiring to DCS, per API 670 vibration trip interlocks per drive can be implemented in the vibration monitoring panel using relay Vibration monitoring system shall give one no. buffered output of 4modules and redundant trip contacts per drive can be wired from vibration The provision as per 20 mA DC. The signal shall be suitable for use as an input to monitoring panel to DCS. Vibration monitoring module can be interfaced to bidding specification shall 21 of 63 DDCMIS as well as for analog recording & analysis, linear in DCS via RS-485 redundant link for monitoring and recording of analog signal. prevail. proportion to vibration velocity as well as displacement. Kindly, confirm this understanding.

113

Volume V, Part B, Chapter 2

2.12.01

24 of 63

Orifice: Root valve material: 316 SS

114

Volume V, Part B, Chapter 2

2.12.01, 2.12.02

24, 25 of One Flow element of each type shall be calibrated in the test 63 laboratory for validation of commutated flow calculations.

Root valve material shall be as per piping design, and not necessarily SS316. The provision as per bidding specification shall Kindly, confirm this understanding. prevail. Each flow element is unique design per its application. So, laboratory calibration test is not applicable. Sizing sheets shall be provided for design verification.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. 115

Volume V, Part B, Chapter 2

2.12.01

Maximum pressure drop/loss shall be limited to 60% of DP for 24 of 63 Orifice plate subject to beta ratio within the range as specified.

Per contract, allowed beta ratio is 0.34 to 0.7. Hence, permanent pressure loss will be as per the permitted beta range. Kindly, confirm this understanding.

116

Volume V, Part B, Chapter 8

8.01.02

2 of 10

For protection against sea environment, all impulse pipes, fittings Sea environment is not applicable for this site, hence this clause is not etc shall be provided with durable epoxy coating with poly urethane applicable. finish. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

SS316H is not used above 500°C applications, and SS316L is not used above 425°C applications. SS316 is best suitable for all high temperature steam services and same can be applied in all services to keep uniform inventory for plant.

117

Volume V, Part B, Chapter 8

8.01.03/ 04

SS tube shall be provided inside enclosures& racks from tee connection to valve manifold and then to instrument. For high The provision as per pressure/ temperature applications (piping class A, B, C & D of the bidding specification shall 2 of 10 table no PCP) the material shall be ASTM A 213 TP 316H it and SS Tubing can be acceptable from the root valve onwards for all the services prevail. for other applications material shall be ASTM A 213 TP 316L. as a standard proven industrial practice. Kindly, confirm this understanding.

118

Volume V, Part B, Chapter 8

8.01.04

Root valve is provided at process end to isolate the hook-up. Manifold has The source shut off (primary process root valve) and blow down isolation or block valve at instrument end to isolate the instrument. Hence, no The provision as per shall be ½ inch size globe valve type for all applications except for separate block valve is required in between the root valve and manifold bidding specification shall 3 of 10 air and flue gas service wherein no source shut off valves are to be isolation valve. prevail. provided. Kindly, confirm this understanding.

119

Volume V, Part B, Chapter 8

8.02.03

1/4-inch size light drawn tempered copper/SS tubing conforming to PVC coating is not applicable for SS tubing. 4 of 10 ASTM B75 shall be used. It shall be at least 0.065 inch and shall be PVC coated. Kindly, confirm this understanding.

120

Volume V, Part B, Chapter 8

8.01.04

3 of 10

Per Volume V, Part B, Chapter 8, 8.03.00 table, 2 root/ drain valves shall be Two root valves are to be used wherever pressure is more than 40 applicable for service having ≥40Barg or ≥ 300°C. Kg/cm2 or Temp>280 deg C. Kindly, confirm this understanding.

121

Volume VII

C&I TD 35

1 of 1

Steam tracing.

Steam tracing is not applicable for this project site ambient. Kindly, confirm this understanding. Vent connection in air service hook-up is not applicable. 122

Volume VII

C&I TD 36

1 of 1

Vent connection in air service hook-up. Kindly, confirm this understanding.

123

Volume VII

C&I TD 42, 48

1 of 1

Vent connection in upper impluse line of level instrument connection.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

Vent connection in upper impulse line of level instrument connection is not applicable as the upper impulse line is connected to the tank for natural venting. Vent connection shall be required only if a local high point is created The provision as per bidding specification shall in the level instrument chamber, per Volume VII C&I TD 49. prevail. Kindly, confirm this understanding.

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Section / Part / Chapter / Volume

Clause No.

Page no.

124

Volume VII

C&I TD 45

1 of 1

Bid Specification Stipulation

M33x2 stub

Statement of Prebid Queries & Clarification Per ASME B31.1 power piping, ASME B1 20.1 NPT stubs shall be acceptable.

Owner's Reply

Confirmed.

Kindly, confirm this understanding.

125

126

Volume V, Part B, Chapter 3

Volume V, Part B, Chapter 14

3.10.04

4, 5, 6

The control system hardware (controllers, modules/cards etc.) If quantity of Remote I/Os is large (suitable for controller capacity loading limit shall be housed in cabinets located in respective control equipment per contract) then, controller shall also be placed inside the remote cabinet. Confirmed. 4 of 10 room (CER) unitised and offsite except for the remote I/O cubicles (as specified in Vol.-V, Part-A) which shall be located in respective Kindly, confirm this understanding. areas

4 of 10 BOP RW DCS, BOP PT DCS, BOP DM DCS

1. BOP RW DCS, BOP PT DCS, BOP DM DCS can be clubbed as single control system (BOP Water System DCS) and common LCR & HMI for PTP/ DM as both are in same zone in layout. 2. Since, BOP RW DCS will be remote IO and extension of BOP Water System DCS, EWS cum OWS or OWS in Raw water pump house is not required. GIU (15" touch screen) can be provided for local monitoring and operation if allowed in local mode from WTP LCR. Alternatively, local push button panel & lamps suffice all local monitoring/ operation needs.

Bidder to follow the tender specification requirements to the extend possible.

Kindly, confirm this understanding.

127

Volume V, Part B, Chapter 14

3

128

Volume V, Part B, Chapter 14

9

129

Volume V, Part B, Chapter 14

13

3 of 10 FW PLC

1. Fire water pump control system can be relay based control system with local control panel as per contract requirement. 2. Fire detection & alarm system shall be OEM's proprietary microprocessor based system.

Kindly, confirm this understanding. Panel mounted 15" touch screen for local operation shall suffice for the ETP ETP PLC - 1 No. EWS cum OWS + 1 No. OWS + control desk and (which has only dosing system and few sumps). 4 of 10 furniture for OWS Kindly, confirm this understanding. PLC based system meeting contract functional requirements shall be provided. 6 of 10 BOP HG DCS Kindly, confirm this understanding.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

130

Volume V, Part B, Chapter 14

131

132

Volume V, Part B, Chapter 14

Clause No.

General - 9

General - 14

Bid Specification Stipulation

For each PLC and Microprocessor based control system, without OEWS (Operating cum engineering Work Station), Laptop along 8 of 10 with software shall be provided for engineering. In addition, LAPTOPs shall be provided as per above Table in Annexure A.

Statement of Prebid Queries & Clarification 1 common laptop with engineering license for all same make PLCs shall be provided. Kindly, confirm this understanding.

This is generic requirement. It depends on the size of the system and local operation requirements. Hence, this shall be decided during detailed Any Package not listed above shall be PLC (redundant hot standby engineering as 15" touch screen operations shall also be acceptable for controllers) controlled with one no. OWS, one no. OEWS 9 of 10 smaller systems. (Operating & Engineering Work Station) and one no. A4 colour LJP. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

General - 14

6 of 10

FGD DCS

Volume V, Part B, Chapter 15

15.01.01, ii

2 of 28

All output signals of all stack monitoring analyzers shall be hardwired and connected to plant DCS/ DDCSMIS as applicable for monitoring, archiving and report generation for environmental monitoring authorities

Volume V, Part A

3.00.01, d

35 of 100 For off-site PLC systems, configuration as per clause 7.01.03(A & B), Part- B, chapter 7 and chapter 14, Part-B, Vol . V shall be provided.

For PLC/ microprocessor based systems, redundant UPS feed shall be acceptable alternative to 24VDC feed system, as a standard proven industrial The provision as per practice. bidding specification shall prevail. Kindly, confirm this understanding.

Volume V, Part A, Annexure II

A Unit HMI

49 of 100 OWS Nos: 1, CWPH Area, CWPH System

Two GIU are already provided in CWPH per contract, hence OWS in local is not recommended from operation management stand.

134

FGD shall be controlled from Stand Alone Common DCS meeting contractual The provision as per functional requirements. bidding specification shall prevail. Kindly, confirm this understanding. Per Volume V, Part B, Chapter 15, 15.01.01 viii, all the CEMS data is available on DDCMIS for analysis and monitoring from CEMS OWS through The provision as per redundant bus. Hence, hardwired signals to DCS are not required. bidding specification shall prevail. Kindly, confirm this understanding.

Kindly, confirm this understanding. Volume V, Part A, Annexure II 136

Owner's Reply

Volume V, Part B, Chapter 14

133

135

Page no.

A Stand Alone Common HMI

51 of 100 OWS Nos: 1, IA/SA Area, IA/SA System

Air compressors and dryers will have OEM's proprietary microprocessor based control system. Overall compressed air system shall be connected to Stand Alone DDCMIS. OWS in local is not recommended from operation management stand. Alternatively, GIU can be provided. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume Volume V, Part A, Annexure II

Clause No. A Stand Alone Common HMI

Page no.

Bid Specification Stipulation

51 of 100 OWS Nos: 2, FOPH Area FOPH System

137

Statement of Prebid Queries & Clarification OWS in local is not recommended from operation management stand. Alternatively, one GIU can be provided. Kindly, confirm this understanding.

Volume V, Part A, Annexure II

A Stand Alone Common HMI

51 of 100 OWS Nos: 2, Aux. Boiler Area, Aux Boiler System

Auxiliary boiler will have stand alone OEM's proprietary microprocessor based control system with 2 OWS per contract.

138 Kindly, confirm this understanding. 139

Volume V, Part A, Annexure II

A Stand Alone Common HMI

51 of 100 GIU Nos: 2, Near Pumps, Makeup Water system

1 GIU is enough for make-up water pumps.

Volume V, Part A, Annexure II

A Stand Alone Common HMI

51 of 100 OWS Nos: 1, CPU REGN

Kindly, confirm this understanding. OWS in local is not recommended from operation management stand. Alternatively, one GIU can be provided.

140 Kindly, confirm this understanding. Volume V, Part A, Annexure II

A Stand Alone Common HMI

51 of 100 OWS Nos: 1, Clarified water Pump House Building CW chemical treatment, CW chlorination, Service Water Pumps.

141

OWS in local is not recommended from operation management stand. GIU for all the pumps in this area per contract are provided. Per Volume V, Part B, Chapter 14, 7, CW Chlorination system is PLC based control system within mimic & local operation push buttons.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. Volume V, Part A, Annexure III 142

1.00.00 b)

59 of 100 Separate sets of FG(s) are to be provided for each of the process If same make DDCMIS is provided and its reliable data bus is already being blocks defined below. The functions of two different process blocks used for signal exchanges required among controllers per proven industrial cannot be mixed. practice, field signals shall be hardwired to the nearest available DDCMIS cabinet ir-respective of its function group as the signal is available for use on the data bus for all the controllers.

The provision as per bidding specification shall prevail.

Kindly, confirm this understanding. Volume V, Part A, Annexure III 143

4.00.00, 62, 63 of Minimum 4, 5, 4 controllers for Water DDCMIS, AHP DDCMIS, 5.00.00, 6.00.00 100 CHP DDCMIS; respectively.

Number of controllers depend on controller loading limit per contract, hence their quantity could be less than the given quantity. Kindly, confirm this understanding.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Volume VIII, C&I - TD

Page no. 7 1 of 1

144

Bid Specification Stipulation Communication bus between controllers and remote IO panels located in CW pump house shall be through fiber optic cable backed up by wireless link.

Statement of Prebid Queries & Clarification Fiber optic links are proposed for being more reliable and as Wireless link PTR may not be available for this application with DDCMIS Suppliers. Kindly, confirm this understanding.

145

146

Volume V, Part B, Chapter 19

19.07.01.9

14 of 25

Redundant Simulation Servers for running the simulation software

Simulation servers could be integral to Instructor's OWS. Kindly, confirm this understanding.

Section1/Chapter1/ Volume III

Owner's Reply The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

2.15.2.

Soot Blowing System shall be i) Fully automatic sequentially controlled through SG C&I control system. 72 of 120 ii) Capable of effectively removing deposited ash from Steam Generator heat transfer surfaces with on load cleaning devices. iii) The soot blowers shall be capable of selective operation in areas of ash deposition (SMART) type or equivalent.

Conventional soot blowers shall be provided as per bidder standard proven practice.

The provision as per bidding specification shall prevail.

Vibration probes & its mounting shall be provided based on Fan supplier's recommendation.

The provision as per bidding specification shall prevail.

147

Section 2/ Chapter1 / Volume III

2.10.8.11.

For mounting of vibration pads/pickups, flat surfaces shall be 47 of 120 provided both in X and Y directions, by the Bidder on the bearing housing

148

Section 2/ Chapter1 / Volume III

2.12.6. c)

Vibration for FD/ID fans: For mounting of vibration monitoring 58 of 120 pads/pickups, flat surfaces shall be provided both in X-Y directions, Please refer above Sr.No. 2.0 by the Bidder on the bearing housing.

The provision as per bidding specification shall prevail.

149

Part A / Volume V

2.03.03

The functional grouping of the above systems shall be as per the 6 of 100 guidelines given in Annexure – III of contract quantities for DDCMIS, Appendix I to part A.

Bidder recommends to follow standard functional grouping as per OEM proven practice which is executed and running successfully in projects in India / World wide.

The provision as per bidding specification shall prevail.

150

Part A / Volume V

3.00.00

Coal Bunker Level Monitoring System (For each coal bunker of 10 of 100 coal feeder using 3D type acoustic wave level transmitter – 1 No. and strain gauge method system – 1set.).

As per Bidder standard design, only One (1) no. of 3D Acoustic wave level The provision as per transmitter is adequate for coal bunker level measurement and Strain Gauge bidding specification shall method will not function properly in high dust environment. prevail.

151

Part A / Volume V

4.00.00 ( g )

12 of 100

Redundancy requirements/Criteria for Sensors & Signals from MCC/SWGR

Bidder clarify that redundancy criteria is considered as per OEM proven The provision as per practice. bidding specification shall Controller grouping, logic implementation and its configuration shall be as per prevail. Bidder’s proven practice for the safe and reliable operation.

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153

154

155

Section / Part / Chapter / Volume Part A / Volume V

Part A / Volume V

Part A / Volume V

Part A / Volume V

Clause No.

Page no.

Bid Specification Stipulation

Owner's Reply

Separate cables are to be provided for dual / triple redundant 16 of 100 instruments used for protection of Unit and HT drives. These cables are also to be laid in separate routes to the extent feasible.

The provision as per Bidder clarify that as per boiler layout, the laying of cables in separate routes bidding specification shall is not technically feasible. prevail.

7.04.00

16 of 100 Complete Instrumentation cables shall be armoured.

All instrumentation cables covered in this specification shall comply with VDE 0815, VDE 0207, Part 4, Part 5, Part 6, VDE 0816,VDE 0472, SEN 4241475, The provision as per ANSI MC 96.1, IS-8784, IS-10810 (latest editions) and its amendments read bidding specification shall along with this specification. prevail. Cables shall be unarmoured as per VDE standard.

7.05.00

Heat resistant instrumentation cable shall be provided for all instruments / equipments/ drives / devices located in hot areas such as Burner tilt, Hot air gates, Air heater areas, Furnace areas, Steam Drain & Vent valves, Turbine & Generator zone etc. This cable shall be laid from instruments / equipments / drives / devices The provision as per from hot area application to a field JB / panel located in areas Bidder clarifies that Heat resistant instrumentation cables are provided only in bidding specification shall 16 of 100 where ambient temperature is around 50 Deg. C. i.e. normal the Burner area. prevail. temperature area. Heat resistant instrumentation cable shall have same specification as of instrumentation cable specified under SubSection chapter 9,Instrumentation and control Cables, Part-B of Technical specification, except that insulation and outer sheath material shall be Teflon. This cable shall be suitable for continuous operation at 205 Deg C.

7.03.00

G1

43 of 100 LIST OF FLUE GAS ANALYSERS PER UNIT

Part A / Volume V

3.01.00 (a)

Guidelines for Functional Grouping of Controllers The stream wise process redundancy is to be maintained in SG C&I DDCMIS. That is, if there are more than one main equipment 59 of 100 (e.g., A/B/C streams) in a process block, these are to be allocated to different FGs, unless allowed explicitly. In the FGs, thus obtained, main equipments of similar streams are to be allocated. For example, if one FG caters to stream.........

Part A / Volume V

3.01.01

60 of 100 Burner Management System:

156

Statement of Prebid Queries & Clarification

Bidder clarifies that 2 no's of High temp O2 Analyser shall be provided at Platen SH Outlet (RHS/LHS) and 6 no's of Low temp O2 Analyser shall be provided at Economizer Outlet (RHS/ LHS) and 2 no's of Low temp O2 Analyser at Economizer Outlet (RHS / LHS).

The provision as per bidding specification shall prevail.

Bidder clarify that redundancy criteria is considered as per bidder proven The provision as per practice. bidding specification shall Controller grouping, logic implementation and its configuration shall be as per prevail. Bidder’s proven practice for the safe and reliable operation.

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157

158

159

160

161

Section / Part / Chapter / Volume

Part A / Volume V APPENDIX - V TO PART – A,

Part A / Volume V

Part A / Volume V

Part A / Volume V

Part A / Volume V

Clause No.

5.00.00

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Bidder have considered the flow measurement as per bidder standard practice as follows: MINIMUM REQUIREMENTS FOR FIELD INSTRUMENTS 1. Mill inlet air flow is as per bidder proven practice based on slant orifice flow The provision as per bidding specification shall 98 of 100 d) Airfoil or venturi flow sections, shall be used for measuring boiler measurement. prevail. combustion airflow with triple redundant Flow Transmitters. 2. FD/ID/PA fans inlet flow based on Pressure measuring Annular pipes at inlet box opening and inlet cone. Level measurement v) Each Economiser hopper, APH Hopper, ESP hopper & Pyrite 98 of 100 hopper must be provided with 3 nos. level switch (switches 2 nos. for high level and One no. for low level.)

Bidder shall provide RF type level switch for ash hopper level measurement. One (1) no. for High level and Low Level switch is not necessary.

The provision as per bidding specification shall prevail.

2.01.00 (ix)

DISTRIBUTED DIGITAL CONTROL, MONITORING & INFORMATION SYSTEM (DDCMIS) Special Requirements for system (refer details below) 1 Software for determination of optimum Controller parameters 2. Performance Calculations (Class I & II) 3. Messaging System 3 of 100 4. Trend Alarms 5. Alarm Analysis 5. Automatic Unit Start-up & Shutdown 8. Replay software for Trip/ Disturbance Analysis 9. Other functions of Control system xiii. System Programming, maintenance & documentation

Bidder clarifies that special requirements for SG-DCS shall be provided based on the features available from Customer approved DCS supplier's.

The provision as per bidding specification shall prevail.

4.00.00 (g) (i)

Triple measurement scheme Triple measurement scheme for analog inputs employing three independent transmitters connected to separate tapping points 13 of 100 shall be employed for the most critical measurements. The same shall be used in analog control functions including, the following but not limited to:..............

Triple measurement scheme shall be followed as per bidder's proven practice.

The provision as per bidding specification shall prevail.

4.00.00 (g) (ii)

Dual measurement scheme For binary and analog inputs required for all other modulating control, protection and interlock conditions purpose of other equipments 13 of 100 and other critical monitoring applications etc., min. dual instruments/sensors shall be provided. ...................

The provision as per Dual measurement scheme shall be followed as per bidder's proven practice. bidding specification shall prevail.

4.00.00 (v)

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Section / Part / Chapter / Volume

Clause No.

162

Part A / Volume V

6.02.00

163

Part A / Volume V 2.0 APPENDIX - I TO PART – A,

3

164

Part A / Volume V 2.0 APPENDIX - I TO PART – A,

Annexure-I TABLE IA/IB:

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

All transmitters, switches etc. in Boiler Turbine Generator measurements (except for all fuel oil applications) shall be suitably grouped together and 16 of 100 mounted inside (i) Local Instruments Enclosures (LIEs) in case of open areas of the plant like boiler area, etc. and (ii) In Local Instrument Racks (LIRs) in case of covered areas like Turbine/Generator area.

Bidder clarify that LIE/LIR will be provided as per Bidder's proven practice.

The provision as per bidding specification shall prevail.

Station C&I DDCMIS System: For 40% of drives distributed in various functional groups (Exact application shall be finalized 23 of 100 during detailed engineering.)

Please refer above Sl.No. 4.0

The provision as per bidding specification shall prevail.

23 of 100 General I/O requirements :

I/O modules will be as per proven DDCMIS OEM standard from Customer approved vendors.

The provision as per bidding specification shall prevail.

Two nos. of 3D Acoustic wave level transmitters shall also be employed for measuring the levels of coal bunker available above the coal feeder/mill.

As per Bidder standard design, only One (1) no. of 3D Acoustic wave level The provision as per transmitter is adequate for coal bunker level measurement and Strain Gauge bidding specification shall method will not function properly in high dust environment. prevail.

165

Chapter 4 / Part B / Volume V

4.12.00

9 of 23

166

Part B / Chapter2 / Volume V

2.05.00

ELECTRONIC WATER LEVEL INDICATOR Bidder clarify that electronic drum level indicator is not applicable for super 8 of 63 Application - HP heaters & Boiler Separator Storage tank and Aux. critical boiler supplied by Bidder. Boiler Drum.

167

Part B / Chapter2 / Volume V

2.06.03

12 of 64

In addition to above, Coal bunker level monitoring system (strain gauge type level measurement) shall also be supplied resulting in triple redundant measurement. Median or average coal bunker level will be chosen for monitoring and for process operations.

Metal Temperature Thermocouple 5) Protective sheath - SS321 6) Protective sheath dia - 8 mm OD 11) Length of T/C - Minimum 30 Mtr

Bidder clarify that Protective sheath material, diameter & Length shall be as per OEM proven standard practice.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

2.14.00

Solenoid valves shall be provided as per NAMUR standard with control valves / pneumatic control valves hooked up with process 38 of 63 interlock requirements and where direct tripping is involved. The number of ways for solenoid valve shall be provided as indicated below:

169

Part B / Chapter2 / Volume V

2.14.00

For operation of the fuel oil corner nozzle valves, fuel oil trip valves etc., double coil solenoid valve ( latch coil & relatch coil) shall be Bidder clarifies that Double / Single coil solenoid valve shall be selected 38 of 63 adopted. based on the application requirement. Single coil usage requires always power and loss of power leads to closure of above valves resulting the unit trip or loss of generation.

170

Part B / Chapter2 / Volume V

2.19.06

48 of 63

168

Part B / Chapter2 / Volume V

171

Part B / Chapter3 / Volume V

One number each Integral Operating Work station separate for ESP control room, for ash Handling system control room and at CHP control room for coal bunkers.

Bidder clarifies that Solenoid valve with NAMUR type shall be considered based on the application requirement.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

Bidder clarifies 1 no. of work station shall be provided for Coal Bunker Level Monitoring at Unit CCR. Any connectivity required to CHP control room shall be taken from the above work station.

The provision as per bidding specification shall prevail.

3.43.02.02

BPS System shall be True Triple modular redundant (TMR) configuration and SIL 3 complaint. The MFT functions shall be implemented in a fault tolerant 2 out of 3 triple modular redundant configuration. Each of the three independent channels shall have its own dedicated processors, multifunction controllers, Bidder clarify BPS System shall be Triple modular redundant (TMR) communication controllers, I/O Modules interface etc. All safety 40 of 85 configuration and SIL 3 complaint. related process inputs shall be fed to each of the 3 channels. All primary sensors for unit/boiler protection shall be triple redundant. The redundancy criteria & wiring shall be done as per OEM proven practice. Additional signal for each trip input shall be made available for 1ms resolution..........Bidder shall certify compliance for already implemented MFT proposed for this contract to EN50156-1:2004 Clause 10....

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

172

Part B / Chapter3 / Volume V

3.12.00

System Programming & Documentation Facility In addition, latest state of the art work-station based system documentation facility shall be provided to generate, retrieve, store Bidder clarifies that these requirements for SG-DCS shall be provided based 7 of 85 on the features available from the Customer approved DCS supplier's. & all system documentation, logic, control loops, cable interconnection, etc. to achieve paperless documentation for the complete plant.

173

Part B / Chapter3 / Volume V

3.17.00

8 of 85

Analog signal conditioning & processing

Analog I/O modules will be as per proven DDCMIS OEM standard from Customer approved vendors.

The provision as per bidding specification shall prevail.

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Section / Part / Chapter / Volume

174

Part B / Chapter3 / Volume V

175

Part B / Chapter3 / Volume V

176

177

Part B / Chapter3 / Volume V

Part B / Chapter 4 / Volume V

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification Binary I/O modules will be as per proven DDCMIS OEM standard from Customer approved vendors.

Owner's Reply The provision as per bidding specification shall prevail.

3.18.00

9 of 85 Binary signal conditioning & processing

3.52.01

Software for determination of optimum Controller parameters The provision as per The programming station shall be equipped with a system/software Bidder clarifies that special requirements for SG-DCS shall be provided bidding specification shall 72 of 85 to calculate the tuning constants i.e. P, I and D values of control based on the features available from the Customer approved DCS supplier's. prevail. loops automatically……………………

3.58.00

Replay Software for Trip/Disturbance analysis Proven software already tested in similar capacity power plants shall be provided. Software based trip/disturbance analysis utility shall be provided. The utility shall have the capability to acquire point information of last 48 hrs. from the Station LAN server or Unit The provision as per historians on a continuous basis and using the acquired data, Bidder clarifies that special requirements for SG-DCS shall be provided bidding specification shall 75 of 85 replay the actual plant mimics with auto updation every second. It based on the features available from the Customer approved DCS supplier's. prevail. shall be possible to select the time interval for which the data is to be replayed. Process alarms, commands from OWS/LVS, UCD commands, GIU commands etc. during the selected time interval shall also be suitably displayed for ease of analysis. Actual no. of points which is to be configured shall be decided during detailed engineering in consultation with the Owner.

4.01.04

In case of tangentially fired boiler, the Bidder shall arrange flame detectors in such a manner that coal flame detectors are available both above and below each coal burner and separate oil flame detectors are provided for each oil burner. In case Bidder has discriminating type flame detectors capable of detecting and 2 of 23 discriminating both oil and coal flame, with the help of a single scanner, the same can also be utilized for monitoring both oil and coal flame per burner. For any other type of firing i.e. nontangential type the flame detectors shall be provided for each coal and oil burner responding only to the flame of its associated burner.

Bidder clarifies that as per OEM boiler design, flame detectors both above or below each coal burner are not required. Having single flame detector for each coal and each oil elevation is sufficient. The arrangement of flame detectors shall be as per OEM's standard and proven practice suitable to its boiler.

The provision as per bidding specification shall prevail.

The same has been accepted by NTPC in its new tenders.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

4.07.01

Bidder shall include in his proposal a Furnace and flame viewing system. The flame cameras shall be suitable for direct online continuous viewing in the central control room of the coal and oil flame and condition of the furnace internals including slagging of the water walls and any other deterioration in the furnace Bidder clarifies that as per OEM boiler design, two cameras are provided 6 of 23 condition. The nos. and type of such flame cameras to be included which is adequate to meet operational an functional requirement. in the proposal shall be selected by the bidder appropriate to his boiler design subject to minimum 4 nos. camera. Separate set of cameras shall be provided for viewing flame and furnace internals based on proven technology for the intended application. The system shall comply to NFPA requirements.

The provision as per bidding specification shall prevail.

On Line Carbon in Ash Analysers System The system shall utilize non sampling/extraction type microwave 10 of 23 technology for online monitoring/ measurement of the unburnt carbon in fly ash with minimum 4 nos. probes measurement to have complete profile per location

The provision as per bidding specification shall prevail.

178

Part B / Chapter 4 / Volume V

179

Part B / Chapter 4 / Volume V

4.13.00

180

Part B / Chapter 11 / Volume V

11.02.04

3 of 9

All SH/RH block valves, shut off valve of LDO & HFO and HP/LP bypass control valve shall have leakage class MSS-SP-61.

181

Part B / Chapter 11 / Volume V

11.03.08

4 of 9

Extension bonnets shall be provided when the maximum temperature of flowing fluid is greater than 280 deg. C

182

Part B / Chapter 11 / Volume V

11.09.01

8 of 9

General Requirements for Critical Application Control Valves -. In case of HP/LP Bypass control valve application, the leakage class should be MSS-SP 61 (block valve leakage).

Bidder clarifies that this measurement is not used for any Boiler controls. Hence, bidder request to exclude from the scope of supply.

The provision as per bidding specification shall prevail. The provision as per Bidder clarify that as per market availability, standard bonnet design available bidding specification shall up to 280 Deg C. prevail. Bidder clarify that leakage class MSS-SP-61 is applicable only for On-Off valves. The same is not envisaged for Control Valves.

Bidder clarify that leakage class MSS-SP-61 is applicable only for On-Off valves. The same is not envisaged for Control Valves.

The provision as per bidding specification shall prevail.

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183

184

185

Section / Part / Chapter / Volume

Part B / Chapter 11 / Volume V

Part B / Chapter 11 / Volume V

Volume VII

Clause No.

11.09.01 (ii) (2)

11.09.01 (ii) (4)

-

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

8 of 9

General Requirements for Critical Application Control Valves -. Valve Trim :Trim of severe/critical service valve shall be of multi stage & multi path design with sufficient no. of discrete pressure drop stage to eliminate the chance of erosion, cavitations, noise, vibration throughout the control range of valve.

Bidder clarifies that multi stage & multi path trim is not envisaged for Aux PRDS Spray valves.

The provision as per bidding specification shall prevail.

9 of 9

General Requirements for Critical Application Control Valves -. Actuator: Actuator type should be pneumatic double acting piston/electro-Hydraulic. All the control valves, isolation, block valves and bypass valves with HP bypass and LP bypass system shall also be provided with electro-hydraulic actuators only.

Bidder clarifies that diaphragm type actuator shall be supplied for non-critical application or smaller size (Less than 3 ") control valve.

The provision as per bidding specification shall prevail.

Tender Drawings for C&I

Bidder could not able to find out tender drawings for Steam Generator related The provision as per Control & Instrumentation equipments like Flame Monitoring System, bidding specification shall Furnace & Flame Viewing System, ASLD, Acoustic Pyrometer, Coal Bunker prevail. Level Monitoring System, etc.

-

186

Vol-V, Part-A

2.03.05

The Bidder shall provide HART system with suitable interface for Analyser are generally not available with HART protocol. each unit DDCMIS only for centralized configuration, maintenance, Hence, bidder understands that analyzers with HART Protocol shall be 6 of 100 diagnosis & recordkeeping for all electronic transmitters, control provided as per availability in the market. Please confirm. valves & analyzers with HART protocol

187

Vol-V, Part-A

2.08.02

For each of the non-DDCMIS based controls being provided for 8 of 100 any system, 1 set of programming tool for each such system shall be provided to view & change logic/program/settings.

Programming tool for proprietary control system (if applicable) shall be integrated within the respective control system OWS/HMI and no separate tool shall be envisaged. Please accept.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail.

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188

Section / Part / Chapter / Volume

Vol-V, Part-A

Vol-V, Part-A 189

& Vol-V, Part-B, Chapter 4

Clause No.

4.00.00 (Note no. 6)

4.00.00 (Note no. 7) & 4.20.01.05

Page no.

Bid Specification Stipulation

For measurement of level of tanks/vessels/sumps containing oil, chemicals or water, Ultrasonic type level transmitters shall be provided. However, other type of level transmitters, if any, shall be 15 of 100 acceptable only if there are constraints on account of process/equipment/device for having an effective measurement using the above. The acceptability of the same shall be subject to Owner’s approval.

Level switches / pressure switches / flow switches/any other process switch etc. for OLCS / Alarms / Interlocks / Protection. 15 of 100 Pressure switches at inlet, outlet of individual pumps and discharge header of pumps for protection and auto & start / stop & alarms shall be provided.

Statement of Prebid Queries & Clarification

DP type level transmitters can also be provided for the measurement of level of tanks/vessels containing oil, chemicals or water etc. based on the technical suitability. DP type level transmitters are very well acceptable & used in the power industry.

Owner's Reply

The provision as per bidding specification shall prevail.

The provision as per The statement mentioned in mentioned clauses are contradictory. Please bidding specification shall clarify whether process switches shall be provided or they need to be avoided. prevail.

20 of 23 & ..Switches shall be avoided....

190

191

192

Level switches for sump/ tank/ vessel/ container/heaters level high/normal/low/very low interlocks shall be provided.

4.00.00 (Note no. 8)

15 of 100

Vol-V, Part-A

4.00.00 (Note no. 10)

15 of 100 DPG, DPT & DPS across the filters/strainers shall be provided.

Vol-V, Part-A

4.00.00 (Note no. 16)

Vol-V, Part-A

& Vol-V, Part-B, Chapter 4

& 4.20.01.05

Bidder understands that for applications where level transmitters are provided, same shall be used for level high/normal/low/ very low interlocks. Separate level switches are not required for interlocks & will not be provided for such cases.

Bidder understands that across filters/strainers DPG, DPT & DPS (all three) The provision as per are not required and either one of them can be provided for the same. Please bidding specification shall prevail. confirm/clarify.

Process switches like pressure switch, level switch etc. shall be provided with triple redundancy for all the applications required for 15 of 100 Trip & protection of HT drives…. &

&

The provision as per bidding specification shall prevail.

The statement given in mentioned clauses are contradictory. Owner may clarify whether process switches shall be provided or they need to be avoided.

The provision as per bidding specification shall prevail. It is EPC Contract. Bidder has to provide.

20 of 23 ..Switches shall be avoided....

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193

Section / Part / Chapter / Volume

Clause No.

Vol-V, Part-A

Page no.

Bid Specification Stipulation

26 of 100 Table - " Drive I/O’s"

Statement of Prebid Queries & Clarification

Owner's Reply

Various type of drives (MOD/MOV, MOVI/MODI, AC-MOV1, AC-MOV2, DSOV, SSOV, SOV/O, SOV/C/L, SOV(1), SOV(2), SOV(3), ACT, CSU, CLCS-1, CLCS-2, CLCS-3, CLCS-4, CLCS-5, CLCS-M etc. etc. ) are indicated in table. Owner may provide the abbreviation details of various type The provision as per bidding specification shall of drives as mentioned above. prevail. Also it seems that the number of I/Os mentioned in the table are not matching with DRIVE INTERFACE SCHEME indicated in volume VII (Tender drawings of C&I) of the tender. Please clarify.

It seems that drives wise number of I/Os mentioned in table are incorrect for few drive types. For example: a) Total no. of binary inputs for LT drives is indicated as 4, but No. of changeover input is indicated as 1 and No. of non-changeover input is indicated as 2 i.e. total 3 DIs. Please clarify. 194

Vol-V, Part-A

26 of 100 Table - " Drive I/O’s"

b) Analog Input signals are not indicated for HT drives, please recheck. c) Total no. of binary inputs for MOD/MOV & MOVI/MODI drives are indicated as 4, but No. of changeover input is indicated as 1 and No. of nonchangeover input is indicated as 2 i.e. total 3 DIs. Please clarify.

The provision as per bidding specification shall prevail.

d) For AC-MOV1 & AC-MOV2 total number of binary input is indicated as only 2. Please recheck & clarify

195

Vol-V, Part-B, Chapter 2

Vol-V, Part-A 196

& Vol-V, Part-B, chapter3

2.06.05

13 of 63

TEST THERMOWELLS (TW) Applicable Standard : ASME PTC 19.3 TW - 2010

26 of 100 Table - " Drive I/O’s" &

&

78 of 85 TABLE – 3.2 DRIVE CONTROL PHILOSOPHY (Typical)

TEST THERMOWELLS (TW) will be as per ASME PTC 19.3 TW - 2016.

The provision as per bidding specification shall prevail.

Number of I/Os (for various drives), indicated in both the mentioned table are not at all matching. For example: As per "Table - Drive I/O’s" the number of I/Os for HT drive are The provision as per 6 DI & 2 DO. However, as per "Table-2" the number of I/Os for HT drive are 8 bidding specification shall DI & 2 DO. prevail. Owner may please check & clarify the same.

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Section / Part / Chapter / Volume

Vol-V, Part-A 197

Clause No.

4.00.00 ('e)

& Vol-V, Part-B, chapter3

198

199

Vol. V: PART A

However, for temp elements including bearing/ winding temp of 11 of 100 motors /pumps temp transmitters shall be provided, with philosophy as defined at e (i). & & 78 of 85 TABLE – 3.2 DRIVE CONTROL PHILOSOPHY (Typical)

Notes:4

The instruments for CHP shall be provided as per standard and Sheet 14 proven practice of CHP supplier. However for temp elements, DIN of 100 rail type temp transmitters mounted in JBs shall be provided.

Sheet 46 Vibration Monitors System per Unit :One set of monitors are to be of 100 provided for :- CHP Control Room,

Vol. V: PART A

I-2

201

Volume V:Part B/Ch. 18

18.02.01(ii)

H

Bid Specification Stipulation

TENDER DRAWINGS- DWN No 111- Page 42 Location of the Control Unit for IRD system. MECHANICAL 12-3605 of 63

200

202

Page no.

Vol-V, Part-B, Chapter 9 Instrumentation 9.02.01 Cables

Statement of Prebid Queries & Clarification

As per Vol-V, Part-A, 4.00.00 ('e), bearing/winding temperature of motor/pumps shall be provided with Temperature Transmitter. Hence, 4-20 mA AI signal will be wired in the DCS. However "Table-3.2", indicates that RTD signal will be wired in the DCS for Pump/motor winding/bearing temperature.

The provision as per bidding specification shall prevail.

Both of the above mentioned statements are contradicting. Owner may please clarify whether 4-20 mA AI signal or RTD signals shall be considered in DCS for Pump/motor winding/bearing temperature measurement.

Location of the Control Unit for IRD system shown in the Side walkway may not be possible due to maintenance point of view. Location of the same shall be decided during detail engineering stage. Kindly check and confirm accordingly.

The provision as per bidding specification shall prevail.

We shall provide Head-Mounted Temperature Transmitter, which is more reliable and economical than DIN Rail-Type Temperature Transmitter. Kindly Confirm the same.

The provision as per bidding specification shall prevail.

As per our standard practices ,we will provide Panel Mounted-LCD (HMI) instead of dedicated Monitor for indication & control . However, same will be interfaced with the main plant vibration analysis & diagnostic system, as mentioned in Note :1(Sheet 47 of 100). Kindly confirm . There will be Soft-link Connectivity between Wagon Tippler & CHP Wagon tippler PLC Connectivity:All DDCMIS,which will serve the Process requirement. Sheet 3 time critical, interlock, control & protection signals will be hardwired Hence, we are not considering any hard-wiring due to long-distance between of 33 to Main CHP DDCMIS which shall be decided during detailed main CHP Control Room & Wagon Tippler Control Room . Engineering. Kindly accept the same. Voltage Grade and Type 4 of 29 660 V/1100 V grade, multipair Annealed tinned copper conductor overall shielded armoured instrumentation cable.

Owner's Reply

Bidder proposes to use 225 V (peak Value) Voltage grade unarmoured instrumentation cables. Armoured instrumentation cables shall be used only in case of buried cables. Please accept.

The provision as per bidding specification shall prevail.

The provision as per bidding specification shall prevail. The provision as per bidding specification shall prevail.

Civil

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Section / Part / Chapter / Volume

Clause No.

Volume II, Chapter 2 Project Information

Page no. Sheet 1 of 7

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

The Contour map for the entire project land is enclosed in Volume- a) The contour drawing furnished with the specification is incomplete as it VII. covers only a part of the project site i.e. ash pond area. Owner to furnish contour drawing for the entire plant.

Owner's Reply

Refer addendum-01

b) Owner to share autocad copy of the contour drawing for the plant site. 2

Vol VI, Ch - 02

3

Volume VI, Chapter-5, Geotechnical Investigation

2.8.1

Sheet 8 of 11

Natural Soil Level (NSL) of the entire plot area varies approximately between 57.00 m to 66.00 m levels. High Flood level (HFL) at project site corresponding to 1 in 100 years return period 62.85 m. Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level. Road level of the plant is to be kept +0.25m to 0.3 m above formation level (+ 64.00 m) and finished floor level of all buildings is to be kept +0.5 m above formation level (+64.00 m). Leveling and grading shall be carried out by selected cutting and filling of existing ground surface and earth. The cutting and filling requirements should balance each other to avoid earth from borrow pits as far as possible. The balanced extra suitable earth in ash dyke area to be used after formation of Ash pond Bundhs in earth filling of plant area.

As per the partial contour furnished with tender document, the natural ground levels are 2 to 3 m lower than high flood level of 62.85 m. Therefore bidder envisages substantial quantum of earth filling for area grading in main plant and BOP area. a) Additional earth, if Also as the ground water table is high in this region, excavation in ash pond required shall be arranged area, may not be possible to get the required earth for area grading (i.e. by Bidders. filling). B)Statutory approvals, In view of the above, Owner is requested to clarify the following points: land acquisition/Right of Use, Royalty charges etc. a)Owner to furnish location of borrow area, which shall be in close proximity with respect to borrow to plant boundary, from where additional earth requirement can be met. area, shall be included in bidder's scope of work. b)Bidder understands that Statutory approvals, land acquisition/Right of Use, Royalty charges etc. with respect to borrow area, shall be included in Owner's scope of work. Please confirm.

Sheet 1 of 4

The soil report is attached at end of this chapter.

Preliminary soil investigation report carried out by Owner, have not been furnished with tender document. Owner is requested to share the same. Refer addendum-01

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

4

Volume I, Section I

2.0

Page 3 of 56

Complete design and construction of realignment of Budha Nallah. Diversion of Budha Nallah: a) Owner to share the detailed study report carried out by IIT Roorkee and For the information of the bidder about the tentative scheme/scope, M/s. Rodic Consultant Private Limited regarding diversion of Budha Nallah. studies carried out by STPL through its consultants can be referred to as b) Bidder understands that the responsibility for taking approval on report under: carried out by M/s. Rodic Consultant shall be Owner's scope. Bidder shall (a) Study carried out by IIT Roorkee carryout necessary diversion work inline with the report, prepared by M/s. (b) Detailed study carried out by M/s Rodic Consultant Private Rodic. Please confirm bidder's understanding. Limited. ............. c) No work regarding diversion of drain/budha nallah is envisaged beyond the Further detailed studies have also been carried out by STPL’s Owner's land boundary. Please confirm. Consultant namely M/s Rodic Consultant Private Limited and the proposed design by the consultant is yet to be approved by Water Resources Dept., Govt. of Bihar. Above study reports are available with the owner which can be obtained, if required by the bidder.

5

Volume III, Chapter 4 - 4.1 Raw Water Intake System

Sheet 2 of 3

Raw Water required for the Power Plant shall be drawn from river Ganga. Single well type Intake Structure shall be constructed in river Ganga for lifting the water from the river and pumping the water to the raw water reservoir inside the plant boundary. The distance from raw water intake structure to raw water reservoir shall be assumed as 9000 M. It is proposed to locate the Raw Water Intake Structure at SITE 3 which is 350 M downstream of the State Govt Intake structure (as per enclosed WAPCOS final report on water drawl study)

Owner is requested to share the below mentioned inputs pertaining to intake water system: a)"WAPCOS final report on water drawl study" is not furnished with tender document. Owner is requested to share the same. b) Location coordinate of intake well. c) Bathymetry study for the intake well and approach bridge area. d) Minimum and maximum water level to be considered for design of intake well e) Pump floor level, Bottom of sump f)Geotechnical investigation at intake location g) L-Section drawing and Route survey of intake piping from intake well upto plant site h) Piping corridor width, earmarked for the intake piping. i) Details of various crossings enroute of intake piping corridor and typical drawings and soil investigation report for the same. j) Location of switchgear building and other electrical facilities

Owner's Reply a) Refer addendum. IIT Roorkee Report has been enclosed. Draft Rodic report is enclosed. However, above both reports are for reference only. Bidder has to make his own assesment. All the said work covers necessary survey, planning & designing by the bidder. b) Getting prior approval of STPL & concerned Authorities, vetting of design engineering & construction drawings and obtaining necessary clearances from concerned Agencies/Dept. towards diversion & drainage work will be responsibility of the bidder.

Please refere Addendum01 A) WAPCOS Report enclosed. For points (b), ©, (d), (e ) (f) refer WAPCOS Report. (g) Route Survey Plan and Contour Plan of route from Intake to Plant Boundary are enclosed. For points (h) , (i) refer route plan . (j) to be planned by bidder.

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7

8

9

10

Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter-5, 5.1 Geotechnical Investigation

Volume VI, Chapter13, IDCT

13.14

Volume VI, Chapter10, RCC Structure & Foundation

10.3

Volume VI, Chapter 6

6.17.00

Volume VI, Chapter 2

2.6 f)

Page no. Sheet 1 of 4

10 of 11

Bid Specification Stipulation As per the soil consultant’s report – Shallow foundation can be used at some locations, However, piling has to be provided for main plant building structures, ESP foundation, TG foundation, mill building foundation, mill foundation, conveyor gallery trestle (of height more than 20m) foundation, junction tower foundation, crusher house foundation, stacker reclaimer foundation & fly ash silo foundation including all other major structures. For conveyor gallery (of height less than or equel to 20m) foundation, type of foundation (pile / open foundation) shall be decided based on findings of final geotechnical report. IDCT Type of foundation - Pile

Statement of Prebid Queries & Clarification Being an EPC Contract, the type of foundation viz. open or pile shall be decided based on detailed geotechnical investigation(to be carried out by successful bidder during detail engg). Hence it is not mandatory to have pile foundation for the structures specified in referred clause no.5.1 Chapter 5, Vol VI. Owner to please confirm acceptance.

Being an EPC Contract, the type of foundation viz. open or pile shall be decided based on detailed geotechnical investigation(to be carried out by successful bidder during detail engg). Hence it is not mandatory to have pile foundation for IDCT.

Owner's Reply

Confirmed.

Confirmed.

sheet 1 of 36

For all other underground structures Owner to allow crack width limited to 0.2 mm as per IS : 456 - 2000. Please such as conveying structures / slurry pump house/ pump houses / confirm. under ground structures such as tunnels, reclaim hopper pit, not in contact with liquid on inside face may be designed as cracked sections with crack width limited to 0.1 mm for both faces.

8 of 9

Pipe line route about 6.00 km in length passes through/under Agricultural Land, Barren Land, Railway Line, Gas Pipe Line, Roads (Highway/Village Roads), Irrigation Land etc. which will be needing the approval of the concerned Authorities which is under the scope of the Bidder.

Make up water piping corridor. Owner to clarify below mentioned points:

Design, Engineering, Procurement, Construction, Testing & Commissioning of merry go round/rail track system outside plant boundary as well as within plant boundary.

a) Railway siding work is excluded from bidder's scope of work, hence Owner to clarify, whether area grading of railway siding area is included in bidder's scope or not? (a) Area grading is in Bidder's scope. b)Incase area grading for railway siding is included in bidder's scope then (b)The FGL level shall be Owner to specify FGL to be maintained for the same. 64.00 M (c ) Not concerned. c) Owner to share the railway feasibility report for Bidder's reference.

2 of 11

Bidder to comply with stipulation of Technical Specification.

a) Bidder understands that Right of Way, Land acquisition including (a) Confirmed. compensation to land Owners, payment of fees to concerned authorities shall be under the scope of Owner. Please confirm or else clarify Bidder's scope. (b) obtaining any approval from concerned b) Design and Drawing approval from statutory authorities, if required, shall statutory authorities if any be under the scope of Bidder. Please confirm. shall be in Bidder's scope.

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Section / Part / Chapter / Volume

Clause No.

Volume III, Chapter 5 - 5.1 Water treatment Plant

Page no. Sheet 2 of 14

Bid Specification Stipulation The river water intake pumps shall be installed in the pump house of canal which shall supply raw water to in plant Raw Water Reservoir of 6 days storage approx. capacity 530,000 cum in two compartments. Three (3) nos. each Raw water and AHP Pumps shall be installed in raw water reservoir.

Statement of Prebid Queries & Clarification Contradiction observed in various subsections of specification. Bidder understands that Raw water reservoir capacity shall be 530,000 cum. Please confirm.

Raw water reservoir capacity shall be 530,000 M3.

Volume VI, Chapter 2 2.6, 22 3 of 11

Owner's Reply

Raw water reservoir of required storage capacity (Minimum 6 days Storage) for running of 2x660MW unit.

Volume II Ch 1 : Intent of Specification 1.2 12

Volume I, Section I

2

Raw water reservoir (5 days) 6 of 12 4 of 56

Following works will be excluded from the bidder’s scope: a) Township c)Administrative block/building

Bidder understands that the all facilities within the compound wall of administrative block and colony/township are also excluded from bidder's scope of work. Please confirm. Confirmed.

Volume VI, Chapter 2

13

Volume VI, Chapter 13, IDCT

2.8.1

8 of 11

13.8.6 b)

8 of 11

Volume III, Chapter 18 18.3.8

18.2

10 of 21

sheet 3 of 21

The scope of this work shall generally cover the Earthwork in Cutting, Filling and Levelling including Transportation of Earth/filling material in project land excluding Township area and administrative office/block area. Earth excavated from Ash Dyke area may be used for site levelling/ filling Tower shall be provided with PVC splash bar.

Bidder shall furnish details of PVC/PP fill regarding fire retarding properties, ageing effect, vibration caused by water and wind effects. The fill material shall be highly resistant to deterioration and shall be fire retardant.

PVC/PP Splash fill shall be provided. Please confirm.

Bidder to comply with stipulation of Technical Specification.

PVC splash bars shall be supported from bottom on RCC piers raised from basin

3.03 sheet 20 of 21 Material of Construction: Splash grid - PVC/PP

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Section / Part / Chapter / Volume

Clause No.

Page no.

14

Volume III, Chapter 33 33.1.1 - Plant layout requirement

2 of 15

15

Volume VI, Chapter 02 2.8.1

8 of 11

16

Volume VI, Chapter 02 2.8.1

8 of 11

Bid Specification Stipulation General layout plan indicating the available spaces for proposed project is as shown in the tender drawing. It shall form the basis for further elaboration by the Bidder for the plant facilities, which are in his scope. Natural Soil Level (NSL) of the entire plot area varies approximately between 57.00 m to 66.00 m levels. High Flood level (HFL) at project site corresponding to 1 in 100 years return period 62.85 m. Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level. Road level of the plant is to be kept +0.25m to 0.3 m above formation level (+ 64.00 m) and finished floor level of all buildings is to be kept +0.5 m above formation level (+64.00 m). Leveling and grading shall be carried out by selected cutting and filling of existing ground surface and earth. The cutting and filling requirements should balance each other to avoid earth from borrow pits as far as possible. The balanced extra suitable earth in ash dyke area to be used after formation of Ash pond Bundhs in earth filling of plant area Formation level of the entire plant area (except ash dyke area and raw reservoir area) has to be kept at 64.00 m level.

Statement of Prebid Queries & Clarification

As the proposed thermal power plant is a green field site, bidder understands that the location of various facilities (except railway siding and ash pond) Confirmed. shown in the tender plot plan are indicative and can be adjusted / relocated as per bidder's layout. Please confirm. In order to optimize cutting and filling quantities, Owner is requested to allow Bidder to decide the formation levels for the plant site considering high flood level. Please confirm.

Bidder to comply with stipulation of technical specification.

RCC retaining wall shall be provided, if necessary as per functional requirement.

............. A RCC retaining wall shall be provided at the junction of different grade levels with provision of stepped stair cases/ramps at different grade level locations for easy movement of persons, etc.

17

General

Owner's Reply

Agreed .

a) Bidder shall be allowed to change the location of ash silo, wagon tippler and track hopper, shown in the tender plot plan. Please confirm.

Adjustment/relocation, if b) Owner is requested to share the railway siding feasibility report with Bidder. required shall be decided in consultation with Owner during detail engineering stage.

18

Volume VI, Chapter 6

6.17.00

8 of 9

Geotechnical investigation and hydrographic study at intake point as well as along pipe line route upto the plant site. 3) Intake Well Complex shall be based on WAPCOS report (copy enclosed)

Bidder understand that intake well location has been already fixed based on WAPCOS report. Hence hydrographic study is not envisaged by the bidder. Bathymetry survey, if required shall be carried out during detailed engineering. Please confirm bidder's understanding.

Refere WAPCOS Report. However, any study/survey if required shall be in Bidder's scope.

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20

Section / Part / Chapter / Volume Volume VI, Chapter 6

Volume VI, Chapter 6

Clause No. 6.17.00

6.17.00

21

Volume VI, Chapter 7

22

Volume VI, Chapter 10 10.16

23

7.2

Volume VI, Chapter 11 11.10

Page no. 8 of 9

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Approach of required length from river bank to water intake well pump house, shall be provided, including support for the intake pipeline. Deck slab of the jetty shall be supported on piles/piers. Width of RCC bridge/ jetty shall be sufficient to accommodate pipes and single lane road of 3.75 m width.

In order to keep all bidders at par, Owner is requested to specify the total width of approach bridge.

RCC pipe pedestal with thrust block shall be provided for over/under ground intake pipe from jetty to the plant area as per approved layout and scheme. Where ever required, culverts, bridges, cross-overs etc shall be provided. The route of pipe line shall be got approved from Owner during detailed engineering stage.

Location of intake well and intake piping corridor upto plant boundary shall be based on Owner's input i.e.WAPCOS report and Make up water piping corridor route details to be furnished as a part of bid document. In case of any change in the aforesaid input by Owner (during detail engineering), bidder shall be suitably compensated with respect to tender provision i.e. GCC clause 39.2, (Changes originating from Employer).

1 of 1

Cement Ordinary Portland Cement (OPC) Grade 43 shall be used for all structures

In place of Ordinary Portland Cement, OPC mixed with Fly Ash shall be used for the structures other that TG foundation, TDBFP/MDBFP and RCC for Chimney shell. Please confirm. Bidder to comply with Batching plant shall have facility for mixing fly ash. Fly ash shall conform to stipulation of technical IS:3812(Part I & Part II). Percentage of fly ash to be mixed in concrete shall specification. be based on trial mix. Mix design shall be done with varying percentage of fly ash mix with cement.

15 of 36

In certain cases crushed stone sand may be added to natural sand Bidder shall alternatively consider manufactured sand conforming to IS:383 in order to achieve the required grading with prior approval of the as a replacement to river sand for major concreting work. Please confirm. Owner. Crushed stone sand alone may be used only with the prior approval of the Engineer for filling and PCC works only.

8 of 9

9 of 16

The pipes shall be encased in R.C.C with a minimum thickness of 250 mm as external protection. However, the actual encasement thickness shall be based on stability against uplift with highest possible ground water level. Further it has to be designed for traffic load at road crossing. Outside RCC incasing, pipe shall be provided with 3 coats of epoxy paint of minimum DFT of 350 microns over two coats of compatible primer after sand blasting.

As per clause 6.17.00(4) deleted in line with WAPCOS Report.

The referred highlighted clause "Outside RCC encasing, pipe shall be provided with 3 coats of epoxy paint of minimum DFT of 350 microns over two coats of compatible primer after sand blasting" is not applicable as the CW pipes shall be encased with 250 mm thick concrete. Please confirm.

Bidder to note that no compensation shall be applicable at later stage. Bidder is adviced to verify all inputs at his own cost.

Confirmed.

CW Pipes shall be minimum 22 mm thick MS Pipes. RCC encasing not envisaged.

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EPC PACKAGE FOR BUXAR THERMAL POWER PROJECT (2 X 660 MW) BIDDING DOCUMENT NO. : BTPP/EPC-01 Dated:29.10.2018 PREBID CLARIFICATIONS-2 Sr. No. 24

Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter 11 11.5.1

Page no. 14 of 16

15 of 16

25

26

27

Volume VI, Chapter 11 11.5.1

14 of 16

11.5.6

16 of 16

2.8.1

8 of 11

Volume VI, Chapter 2, Scope of work

Volume VI, Chapter 16 16.0

1 of 2

Bid Specification Stipulation Free board of 500mm minimum shall be maintained. The maximum level of Reservoir will be kept at level which will be at least 500 mm below the finished floor level of the plant or just at the plant formation level.

Statement of Prebid Queries & Clarification a) Owner to clarify the ambiguity between clauses about Free board and Top of embankment b) Bidder shall be allowed to decide embankment top based on cut fill balance. Please confirm.

Due to the length of the reservoir, waves may be set up by wind blowing over it. According to IS: 10635 a wave height of 1.0 m may be obtained hence the free board is kept as 1.0m. Hence the top of embankment is kept 500 mm above the finished floor level of Main Power House building. Reservoir will be lined with H.D.P.E liners and protective plains Bidder understands that the Reservoir lining shall be as per clause no. cement concrete layer of grade M-15 and shall be provided in 11.5.1. Please confirm. panel over a cement sand plaster in 1 : 6 to avoid damage of the liner. Hence sand / fine ash base course of appx 100 mm thickness and 25mm thick 1:4 cement mortar as plaster followed by PCC (M-15) precast/cast in situ cover in panels or ash bricks lining filled up with fine sand in the gap between bricks may be considered.

Plant leveling and grading shall comprise of clearing and grubbing, tree cutting, depositing the wood pieces with the Owner, disposal of spoils as per direction of engineer, removal of shrubs and bushes, excavation, back filling compaction observing safety measures during progress of work etc.

Owner's Reply

Free board to be kept 1.5 M & embankment 500 mm above FFL of Main Power House Building.

Confirmed.

a) Felling of trees shall be excluded from bidder's scope of work. Please confirm. b) In case tree cutting to be included in bidder's scope, then Owner to take necessary permission from statutory authorities including forest department, before handling over of site for levelling and grading. Please confirm.

Total ash produced in the plant at about 85% PLF will be disposed Please confirm that bidder's scope is limited to the construction of starter dyke and further raising shall be in Owner's scope. in the form of slurry by pumping into the ash disposal pond. The dyke around the storage shall be planned to be constructed in stages. The starter dykes around the storage pond shall have total storage capacity to store ash produces in 4(four) years of plant life. Keeping safety in regards to highest flood level in the plant area, the top level of the starter dyke should be kept at 64.00 m level Thereafter, the raising the dykes shall be in stages of 3 metre effective height increase (top of dyke in lower phase to top of dyke in higher phase). The ultimate dyke height shall be 12m.

Confirmed.

Confirmed.

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29

Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter 16 16.0

Volume VI, Chapter 16 16

Page no. 1 of 2

1 of 2

Volume VI, Chapter 16 16

1 of 2

Volume VI, Chapter 16 16

1 of 2

Volume VI, Chapter 16 16

1 of 2

Bid Specification Stipulation Total ash produced in the plant at about 85% PLF will be disposed in the form of slurry by pumping into the ash disposal pond. The dyke around the storage shall be planned to be constructed in stages. The starter dykes around the storage pond shall have total storage capacity to store ash produces in 4(four) years of plant life. Keeping safety in regards to highest flood level in the plant area, the top level of the starter dyke should be kept at 64.00 m level Thereafter, the raising the dykes shall be in stages of 3 metre effective height increase (top of dyke in lower phase to top of dyke in higher phase). The ultimate dyke height shall be 12m. ........................ for developing storage capacity, one storage lagoon for Fly Ash disposal of 9 years (as per MOEF notification) by High Concentration Slurry Disposal (HCSD) system with sedimentation basin and one storage lagoon for disposal of 9 years (as per latest MOEF notification)

Statement of Prebid Queries & Clarification Contradiction in clause. Owner to confirm that for the purpose of checking stability of starter dyke, whether the ultimate dyke height shall be governed by storage capacity of 18 years or 12 meters?

The starter dyke shall be strong enough to withstand the loads from all the future higher stage dykes as well as from the ultimate filli 100% fly ash utilization is not achieved then additional land a) In order to keep all bidders at par, Owner to clarify the basis for calculating In hcase shall be required, depending on the extent of ash utilization. 4 years of ash storage volume for starter dyke. Bidder understands that the storage capacity of ash dyke for 4 years shall be The starter dykes around the storage pond shall have total storage calculated as per the latest guidelines laid down by MOEF wherein fly ash capacity to store ash produces in 4(four) years of plant utilization by Owner shall be atleast 50% at the end of first year, 70% at the life………………. end of second year, 90% at the end of third year and 100% at the end of For developing storage capacity, one fourth year. For bottom ash, 100% bottom ash volume generated shall be storage lagoon for Fly Ash disposal of 9 years (as per MOEF disposed to ash dyke for four years. The ash dyke storage capacity for notification) by starter dyke shall be calculated based on this concept. Please confirm High Concentration Slurry Disposal (HCSD) system with bidder's understanding. sedimentation basin and one storage lagoon for disposal of 9 years (as per latest MOEF b) Bidder shall refer ultimate height of ash dyke only for checking of stability notification) bottom ash by wet slurry disposal system with one of starter dyke. Ultimate storage calculation is not in bidder's scope of work. overflow Please confirm. lagoon for storing decanted water from above storage lagoons will be constructed. As per MOEF notification, 100 percent fly ash utilization is to be achieved progressively within 4 years starting with 50% in 1st year and 70% & 90% in 2nd & 3rd year respectively of plant

Owner's Reply Starter dyke shall be constructed for 4 years ash generated while firing worst coal at TMCR for 2 units operating at 85% PLF and ash density as 1.4 T/M3. Bidder shall consider a free board of 1 M above the max. ash level. . HCSD System not envisaged in the project. Stability of dyke shall be carried out for ultimate height of dyke. Ultimate height shall be considered as 18 M.

Starter dyke shall be constructed for 4 years ash generated while firing worst coal at TMCR for 2 units operating at 85% PLF and ash density as 1.4 T/M3. Bidder shall consider a free board of 1 M above the max. ash level. HCSD System not envisaged in the project. Stability of dyke shall be carried out for ultimate height of dyke. Ultimate height shall be considered as 18 M.

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Section / Part / Chapter / Volume

Clause No.

30

Volume VII, Layout

31

Volume VI, Chapter 16 16.0

32

Volume VI, Chapter 14 14.2

Page no.

1 of 2

6 of 23

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

Plot Plan Drawing No. 111-29-0200, Rev R0 Ash Dyke Area = 307 acres

a) Bidder understands that the ash pond layout/shape & location coordinates shown in the tender plot plan are indicative in nature and are subject to (a) Confirmed, however modification by bidder during detail engineering, keeping the storage with STPL approval during requirement intact . Please confirm bidder's understanding. Deatiled Engineering by Bidder. b)Fencing is shown all along the periphery of ash pond. Bidder understands (b) Confirmed. that the same is also included in Bidder's scope of work. Please confirm.

Keeping safety in regards to highest flood level in the plant area, the top level of the starter dyke should be kept at 64.00 m level

Top of embankment for starter dyke shall be decided by bidder with respect to storage requirement and cut fill balance. However the top of embankment shall be kept above plant finished grade level. Please confirm.

Piling shall be used for foundation of trestles supporting overhead conveyor galleries.

Pile / open foundation shall be provided as per approved soil investigation report to be carried out by EPC Contractor during detail engineering. Please confirm.

14.4 Piling shall be used for the foundation of crusher house.

Agreed . Minimum +65.00 M level.

Agreed .

14.5 Piling shall be used for the foundation of stacker reclaimer. 33

Volume VI, Chapter 1 of 23

14.1

1 of 23

The vertical and inclined portion of coal hopper, the beams and top Only the inside portions of the hopper (for wagon tippler & Reclaim hopper) of coal are provided with 50 mm thick gunniting and not the entire inside surface. tray in the track hopper structure as shown in the tender drawing Please clarify. shall be provided with 50 mm thick guniting (shotcreting). Complete inside surfaces of Wagon tippler & reclaim hopper shall also be provided with 50mm thick guniting.

Bidder to comply with stipulation of technical specification.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Volume III, Chapter 27 27.10.3

13 of 35

Specific technical requirement of laying buried pipe with anti corrosive treatment a. Buried piping shall be coated and wrapped, after completion of welded and/or flanged connections

27.12.1

14 of 35

Buried Piping External surfaces (i) Surface cleaning by Sand Blasting.

Statement of Prebid Queries & Clarification

Owner's Reply

Owner to please confirm coating/protection/encasement requirement for CW pipe due to contradiction of clauses.

The same shall be as per VI Chapter 11.

Volume VI, Chapter 11

35

11.10

9 of 16

The pipes shall be encased in R.C.C with a minimum thickness of 250 mm as external protection.

Volume VI, Chapter 12 12.5.1

7 of 22

The liner shall be of corrosion resistant steel type “COR-TEN B” of minimum 10 mm thick. Top 10m length or length equal to 2 times flue diameter whichever is larger shall be provided using material confirming to AISI:316L or BS:1449. The chimney Flue liner cladding shall be made of 2 mm THK Titanium (Grade 2 as per ASME-SB265) OR C-276 Alloy over 8 mm THK (Minimum) Mild steel base metal of Flue liner. Cladding shall be done to achive the requiality as per ASTM-B 898-11. Alternately contractor may provide Borosilicate Glass Block lining system. (The thickness of Borosilicate Glass Block shall be decided by bidder based on corrosion resistance of the material for worst composition of flue gases and considering 30 plus years of plant life subject to minimum thickness of 50 mm). The lining material should withstand

Contradiction in clause. Owner to clarify whether to consider flue liner as 10 mm thick CORTEN B or Alloy/Borosilicate lining over 8 mm thick mild steel?

Alloy/Barosilicate lining over 8 mm thick MS shall be considered.

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Section / Part / Chapter / Volume Volume VI, Chapter 2

Clause No.

Page no.

2.6, 20

3 of 11

4.5

2 of 3

27.3.5

6 of 35

Bid Specification Stipulation A raw water intake pump house & intake structure on river Ganga bank and pipe line (MS/GRP) from Intake to raw water reservoir in the Plant area.

Statement of Prebid Queries & Clarification

Owner's Reply

Contradiction in clauses for the MOC of raw intake pipe. Bidder understands that GRP pipes are also acceptable to Owner as per clause no. 2.6, Volume VI, Chapter 2. Please confirm.

Volume III, Chapter 4

Volume III, Chapter 27

The scope of work shall include piping from pump discharge to raw water Pump house with necessary pipe supports, motorized isolation valves, NRVs, air release valves etc as required for completeness of the system. Intake water pump discharge pipe size shall be minimum 1200 mm spirally welded pipe to IS: 3589. Thickness of the pipe shall be as mentioned in Chapter 27 – Low Pressure Piping.

GRP Pipe is not acceptable.

Material of construction for pipes carrying various fluids shall be as follows: Raw Water Intake - IS-2062 Gr. B / ASTM-A-36 / ASTM A-53 type ‘E’ Gr. B/IS-3589 Gr. 410/IS-1239 (Heavy).

37

Volume III, Chapter 27 27.10.3

27.12.00

38

Volume III, Chapter 27 27.10.2, c)

13 of 35

Coating and wrapping/ Anti corrosive Protection Coal tar tape

14 of 35

Painting of Pipes External surfaces (i) Surface cleaning by Sand Blasting. (ii) Coal tar primer compatible with coal tar enamel grade. The number of coats shall be two with a DFT of 35 microns each.

13 of 35

On the internal surface for pipes 1000 NB and above, a coat of primer followed by a hot coal-tar enamel or coal tar epoxy painting (cold) shall be applied.

Owner to clarify the clause to be followed for external coating of Make up water and ACW piping, either clause no. 27.10.3 or clause no. 27.12.00.

Clause 27.10.3

Internal painting for pipes: Bidder understands that the referred clause is applicable for both make up water and CW pipes. Owner to kindly clarify. Confirmed.

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Section / Part / Chapter / Volume Volume VI, Chapter 2

Clause No. 53

Page no. 5 of 11

Bid Specification Stipulation Dispensary and first aid centre.

Volume VI, Chapter 11 Service building - Safety and Welfare Cell, First aid room

40

41

42

Statement of Prebid Queries & Clarification a) Bidder understands that first aid room is a part of service building and no separate building is envisaged for the same. Please confirm.

b) In case a separate building for dispensary and first aid center is envisaged Confirmed. then Owner to furnish the building size and brief specification.

11.12.1 b

10 of 16

Volume II, Chapter 2

1.13.6

2 of 7

Project Information Basic Wind Speed : 39.0 m/s As per IS: 875 part – III

Volume VI, Chapter 8: Loading

8.6

Sheet 4 of 5

Basic wind speed at project site is 47 m/sec . as per IS:875 -1987 Part-3

1 of 3

The main plant access road and a portion of the main plant complex circumferential road shall be Type I.

In order to keep all bidders at par and avoid dispute during detail engineering, Bidder requests Owner to specify upto what extent the Type I road is required for the main plant complex area.

Type II roads shall consist of one 7.0 metre wide RCC paved carriageway with 1.5m wide hard shoulders with drains on both sides. A turning area at blind ends shall be provided. Plant areas where infrequent access is needed shall be served by Type II roads. Examples of Type II roads are the lay-down area roads.

a) Laydown area roads are of temporary in nature and are not part of main road network. Also the said roads shall be constructed as per EPC Contractor's requirement and the same will be dismantled at a later date. Hence example of type II roads as laydown area roads is not applicable. Please confirm.

Volume VI, Chapter 23 23.1

Volume VI, Chapter 23 23.1

1 of 3

Owner's Reply

Contradiction in clause. Owner to clarify the basic wind speed to be considered for 2x660 MW SJVN Buxar project. Wind speed of 47 m/sec to be considered.

Type I Road shall be considered as per specification.Please refer Addendum also.

Agreed .

b) Bidder understands that access roads to Plant facilities shall be Type II roads unless specifically mentioned in the specification. Please confirm.

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Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter 23 23.1

Page no. 1 of 3

Bid Specification Stipulation Type III roads shall be 3.75 m wide with 1.0m wide hard shoulders on one side. Type III roads shall be provided along the plant boundary for access for security and maintenance

Volume II, Chapter I 1.0

Statement of Prebid Queries & Clarification Owner to clarify the following: a) Plant bypass road and its adjacent drain including culverts within the Owner's land boundary, shown in the tender plot plan are not included in Bidder's scope of work as per clause 1.0, Exclusions. Please confirm. b)Bidder's scope will include construction of peripheral/patrol road inside the plant boundary wall (which is being constructed by Owner). Please confirm.

4 of 12 Following works will be excluded from the bidder’s scope: g) Approach road(s) and associated works outside plant boundary

44

Volume VI, Chapter 21 21.2 e)

1 of 11

The rectangular drains shall be minimum 450 mm wide of RCC construction.

21.3 b)

2 of 11

All storm water drainage shall preferably be through open storm water drains. These shall be provided on both sides of the roads and shall be designed to drain the appropriate catchment area including road surface, open and covered area etc. The drains shall be minimum 300 mm wide at the base.

Volume VI, Chapter 23

45

Volume II, Chapter 4 Provenness

23.1

2 of 3

4.2.1

6 of40

The Bidder/ its sub-vendor should have designed, constructed and commissioned at least one (1) Induced Draft Cooling tower in RCC construction with splash type fill / film type, of capacity not less than 70,000 cum/hr or 80% of offered capacity whichever is lower and which should have been in successful operation for at least one (1) year prior to the date of Techno Commercial bid opening.

Owner's Reply

It is included. a) Confirmed. b) Patrol road inside plant boundary in bidder's scope.

Bidder shall consider 300 mm as minimum clear width of storm water drain as per clause 21.3 b). Please confirm.

Confirmed.

The flow rate of 70000 cum/hr for IDCT is too high and most of the reputed vendors are not qualifying the said requirement. Bidder request Owner to change QR for IDCT " as below "The Bidder/ its sub-vendor should have designed, constructed and commissioned at least one (1) Induced Draft Cooling tower in RCC construction with splash type fill / film type, of capacity not less than 32000 cum/hr or 80% of offered capacity whichever is lower and which should have been in successful operation for at least one (1) year prior to the date of Techno Commercial bid opening".

Bidder to comply with stipulation of technical specification.

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Section / Part / Chapter / Volume Volume II, Chapter 4 Provenness

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

4.2.1

6 of 40

The Bidder/ its sub-vendor should have designed, constructed and Contradiction in provenness criteria for IDCT. commissioned at least one (1) Induced Draft Cooling tower in RCC Bidder understands that clause no. 4.2.1 and 4.2.2 of Volume II, Chapter-4, Provenness shall prevail over Attachment 3K. Please confirm. construction with splash type fill / film type, of capacity not less than 70,000 cum/hr or 80% of offered capacity whichever is lower and which should have been in successful operation for at least one (1) year prior to the date of Techno Commercial bid opening.

18.3.8

10 of 21

Attachment 3K DETAILS OF Cooling Tower (as per clause 4.2.1 of Chapter 04, “Provenness” , Volume II of Bidding Documents In support of Sub-Qualifying Requirements of Clause 4.2.1 of Chapter 04, “Provenness” , Volume II of Bidding Document, we confirm that our Sub-vendor M/ s........................ have designed, constructed and commissioned at least one (1) number Induced Draught Cooling Tower in RCC Construction with splash type fill, of capacity not less than 70000 M3/hr or 80% of offered capacity whichever is lower which is in Further, NOC for diversion of the existing Budha Nallah has been Owner to furnish "certain conditions (annexed in the Bid document)" granted pertaining to diversion of Budha Nallah, as the same is missing in tender by Water Resource Department, Patna Govt. of Bihar with certain document. conditions (annexed in the Bid document)

Owner's Reply

Volume III, Chapter 18

47

48

Volume VI, Chapter 2, Scope of work

Volume VI, Chapter 2, Scope of work

Volume VI, Chapter 2

2.8.4 (i)

2.8.4 (ii)

2.6 g)

11 of 11

13 of 11

2 of 11

Outfall Structure: An outfall structure will be constructed on the Northern side of the project in to which the diverted Budha Nallah and the Eastern peripheral drain will discharge and the flows coming from the outfall structure will fall in to the Budha Nallah running on the Northern side. The outfall will be kept in between the fence and boundary wall of the plant area. The discharge channel coming out from the outfall structure will drain in to the Budha Nallah on the Northern side.

Owner to clarify the below mentioned points regarding drainage system for the plant: a) Bidder understands that the Outfall location is within the Owner's land acquisition boundary. Please confirm. b) Owner to indicate the location coordinates of the outfall location and terminal point of diverted Budha nallah which is included in Bidder's scope. c)Bidder shall terminate discharge channel (from outfall location), within Owner's land acquisition line. Scope of work pertaining to diversion of Budha nallah beyond the land acquisition line is not included in Bidder's scope. Please confirm.

Agreed . Bidder's understanding is correct.

Enclosed. Please refer Addendum - 01

Bidder has to design the diverson work & location of outfall within plant boundary.

Following works will be excluded from the bidder’s scope:

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Section / Part / Chapter / Volume Volume VI, Chapter 2, Scope of work

Clause No. 2.8.2

Page no. 11 of 11

Bid Specification Stipulation as well as inspection road along ash disposal pipe route inside and outside the plant boundary as required, access road to Raw Water Intake structure along raw water pipe line, raw water reservoir.

Statement of Prebid Queries & Clarification a) For the inspection road along ash disposal pipe, Owner is requested to provide below mentioned information: -- Width of the road? - Type of the road Rigid or Flexible pavement? - Whether drain is required along side access road? b) For access road to raw water intake structure, Owner is requested to provide below mentioned information: - Route survey indicating the start and end point of the access road. - Road elevation? - Width of the road? - Type of the road Rigid or Flexible pavement? - Whether drain is required along side access road?

50

Volume VII, Layout

Plot Plan, D-0444

Bidder understands that the road width shown in the Plot Plan is corridor width inclusive of carriage way, shoulder etc. Actual width of road shall be as per specification.

Owner's Reply

Type-III Road as per specification shall be considered.

Type-III Road as per Specification shall be considered.

Agreed . However, Plot Plan shall also be referred.

Topography Drawing and Plot Plan

Please share the autocad version of the topography drawing and Plot Plan.

Enclosed. Please refer Addendum-01

Vol. VI/ Ch 06

Vol-VII-TD-Civil- 1 Final 6.02 1

Approach to EOT crane shall be ensured by Cage ladder and staircase.

Bidder proposes to have access by cage ladder to approach the EOT.

Bidder to comply with stipulation of technical specification.

53

Vol. VI/ Ch 06

6.07.02

3

Ladders with cages will be provided for top of ladders more than 6m above Ladders shall be provided with a safety cage of minimum 750diameter clear when the top of ladder is more than 4.5m above the landing level, as per National building code/ Industrial Practice. the landing level

54

Vol. VI/ Ch 06

6.08

3

For RCC stairs, handrails with 20mm square MS bar balustrade with suitable MS flat & Teakwood handrail shall be provided, unless specifically mentioned otherwise

51

Vol. VII

52

Bidder propose to use MS handrails for all buildings and structures except for service building. Please confirm.

Bidder to comply with stipulation of technical specification. Hand railing shall be galvanized.

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57

58

59

Section / Part / Chapter / Volume Vol. VI/ Ch 06

Vol. VI/ Ch 08

Clause No. 6.11

Page no. 4

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

All underground structures like water retaining structures, track hoppers, transfer house, conveyor tunnel & other deep underground structures etc., shall have plasticizer cum water proofing cement additives conforming to IS:9103. In addition, limits on permeability as given in IS:2545 shall also be met with. Over water proofing membrane, 25mm thk CM 1:3 mixed with approved water proofing compound at the rate specified by the manufacturer shall be provided over which protective layer of 15mm thk kota / cuddapa or equivalent stone with joints sealed with C1:3 shall be laid. Over this stone layer, 25mm thk CM 1:3 mixed with approved water proofing compound at the rate specified by the manufacturer shall be applied before RCC base slab shall be casted Impact Load

Bidder proposes to use polymer modified waterproofing slurry treatment both for base and side walls in contact with earth, instead of tender specified waterproofing treatment.

Bidder to comply with stipulation of technical specification.

8.4 8.10

4 5

Vol. VI/ Ch 09

9.4

4

minimum thickness of structural steel elements 8mm o/p & above e) chequered plates

Vol VI/Ch 07

7.1

1

Chequered plate shall conform to IS: 3502 (latest) and minimum thickness of chequered plate for floorings, covers etc shall be 6 mm O/P.

Vol. VI/ Ch 11

11.12.2

10

Storage Yard A storage yard of 25,000msq shall be provided with a provision 5000m.sq. covered area.

The 25,000 sq.m area requirement is inclusive of the 5000 sq.m provision for covered area. Please confirm.

Parking Sheds Covered parking area for at least 30 cars and 60 scooters (two wheelers) with RCC canopy shall be provided.

Our understanding is that the total number of parking sheds in the plant would cover 30 cars + 60 2-wheelers. Please confirm.

Vol. VI/ Ch 11

11.12.3

11

Owner's Reply

Contradiction in clause 8.4 and 8.10 regarding impact load due to cranes. Impact load due to cranes and hoist shall be followed as per IS:875. Please confirm.

IS:875 shall be followed for impact load.

Contradiction in clauses. Owner to confirm which clause to be followed regarding minimum thickness of chequered plate? Chequered Plate of min. 6 mm thk shall be used.

Confirmed.

Bidder's understanding is correct.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

60

Vol. VI/ Ch 16

16.0

1 of 2

Total ash produced in the plant at about 85% PLF will be disposed a) Please furnish the storage volume in cubic meters or metric ton to be in the form of slurry by pumping into the ash disposal pond. The stored (for fly ash and bottom ash pond) in the starter dyke for proposed ash starter dykes around the storage pond shall have total storage pond. capacity to store ash produces in 4(four) years of plant life. b) As per mechanical specification, HCSD system is not asked and only lean slurry system have to be provided. Hence separate storage lagoon for HCSD For developing storage capacity, one storage lagoon for Fly Ash is not envisaged. Please confirm. Refer S.No.28 above. disposal of 9 years (as per MOEF notification) by High Concentration Slurry Disposal (HCSD) system with sedimentation c) As HCSD lagoon is not required, whether two separate lagoons are to be basin and one storage lagoon for disposal of 9 years (as per latest provided within the proposed ash pond? Owner to kindly clarify the same. MOEF notification) bottom ash by wet slurry disposal system with one overflow lagoon for storing decanted water from above storage lagoons will be constructed.

61

Vol. VI/ Ch 16

16.0

1 of 2

Provision for the extension of HCSD pipes from HCSD lagoon to As per mechanical specification, HCSD system is not envisaged. Hence the Bottom ash lagoon shall be kept during the initial phase of the referred clause is not applicable. Please confirm. HCSD disposal. To avoid fugitive ash dust emission and for promoting vegetation Owner to clarify the requirement as the same is not in Bidder's scope. cover, the final ash surface will be covered with 300 mm thick earth cover.

62

63

64

Vol. VI/ Ch 16

Vol. VI/ Ch 16

Vol. VI/ Ch 16

16.0

16.0

16.1 (e)

1 of 2

1 of 2

3 of 2

Bidder understands that freeboard for starter ash dyke shall be 1 m. Please Ash slurry shall be pumped into the storage pond, where the ash particles shall settle. The slurry shall accumulate within the pond till confirm. the water level reaches the design FRL (Full Reservoir Level) i.e. 1 meter below dyke top in each phase. Ash Pond u/s slope and HDPE lining of bed portion shall be provided with 1 mm thick. The lining shall be procted with cement sand mortar under 50mm precast concrete slab of grade M-15 complete.

Confirmed.

Confirmed.

Confirmed.

Bidder understands that only U/S slope needs to be provided with precast concrete slab lining and there will not be any protection for the pond bed (except 30 acres) as per clause 16.0. Please confirm. Confirmed.

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Section / Part / Chapter / Volume Vol VI, Ch - 16

Clause No. 16.0

Page no. 1 of 2

Bid Specification Stipulation Further, to start with only about 30 acres of land in one of the bottom ash lagoon will be provided with impervious liner and balance part of the bottom ash lagoon shall be lined by spreading high concentrated fly ash during initial stage of slurry disposal.

Statement of Prebid Queries & Clarification

Owner's Reply

a) 307 acres of Ash pond area has been earmarked in the Plot Plan. Bidder request, Owner to earmark 30 acres area within which impervious liner to be provided. Bidder to comply with b) Also, spreading of high concentrated fly ash during initial stage of slurry stipulation of technical disposal is not included in bidder's scope and any kind of liner is not required. specification. Please confirm. c) Owner to specify the material and thickness of the impervious liner.

66

Vol-VI/ Ch- 14

14.14

13

Wearing course at top, shall consist of 25 mm thick P. C. C. (M-15) Chequered concrete tile path way will be provided along the parapet wall and cast wire mesh and sealing of joints using sealing compound / for equipment access placed on terrace. Please confirm. elastomeric water proofing membrane. Pathways for handling of materials and Confirmed. movement of personnel shall be provided with 22 mm thick chequered cement concrete tiles as per IS : 13801 for a width of 1000 mm in place of P. C. C.

67

Vol-VI/ Ch-17

17.2.0 (v)

2 of 20

All handrails and ladder pipes (except at operating floors) shall be Contradiction in clause. All handrails will be 32mm nominal bore MS pipes as per clause 6.08 of Vol 50mm nominal bore MS pipes (medium class) conforming to IS:1161 and shall be galvanized as per IS:4736 treated with primer VI/ Ch-2. Please confirm. and finished with suitable paint. All rungs and ladders shall also be galvanized. Minimum weight of galvanizing shall be 610 g/sqm.

68

Vol VI, Chap 02

6.08.00

3 of 9

All handrails shall be of 32mm nominal bore MS pipes (medium class) as per IS:1161 galvanised using 750 gm/sq. m of zinc.

Vol-VI/ Ch-17

17.7.1 (b - i)

5 of 20

Outside plaster on masonary wall: no plastering is required on outside of masonary wall. Since outside surface of brick wall will be exposed, contrctor to manufacture good shape bricks to suit the exposed brick work. Silicone coating shall be provided on outside exposed face of brick wall.

Table-1

17 of 20

All handrails shall be of 32mm nominal bore MS pipes (medium class) as per IS:1161 galvanised using 750 gm/sq. m of zinc.

Contradiction in clause. Considering the general Industrial practice and as specified in Table 1 Finishing schedule of Chapter 17, external plaster along with paint will be followed. Please confirm. Confirmed.

Table-1 : Finishing Schedule STG Building - Ground floor ------- Wall (External) - Water proof cement based paint

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Section / Part / Chapter / Volume Vol-VI/ Ch-17

Vol-VI/ Ch-17

Clause No. 17.7.5 (f)

17.7.6(c)

Page no. 9 of 20

10 of 20

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Ceramic Tiles Bidder propose to use GLAZED CERAMIC tiles for Dado. Please confirm. Heavy duty anti skid ceramic tiles with matt finish shall be used in toilets, pantry, dining hall of canteen, locker rooms etc. The tiles shall be 300 x 300 x 10 mm of approved colour / shade and brand. Dado in toilets and pantry, locker rooms etc shall also be of similar finish For walls of neutralizing pit, the same specification as 1.10.2 shall apply except that thickness of the brickwork shall be 115 mm with suitable pilasters at 2000 mm c/c.

Unable to locate clause 1.10.2 in tender document. Owner to please furnish the same.

Owner's Reply

Confirmed.

Clause 1.10.2 shall be read as Clause 17.7.6 (b)

71

Vol-VI/ Ch-17

17.7.7 ( e)

11 of 20

Staircase wall shall be given dado of cast in situ terrazzo to a Cast in situ terrazzo can not be provided in walls. Hence Bidder shall provide height of 2100mm. If Entrance lobby and lift area in Service ceramic tiles. Please confirm. building and Admin building shall be provided with granite tile dado Confirmed. to a height upto false ceiling level.

72

Vol-VI/ Ch-17

17.7.10

13 of 20

For single glazed aluminum partitions and doors, Float glass or flat Please confirm clear float glass or Toughened glass for partition and doors. transparent As toughened glass is recommended for doors and partitions. sheet glass of minimum 6 mm thickness shall be used.

Toughened glass shall be provided.

73

Vol-VI/ Ch-17

Table 1 (Finish Schedule)

19 of 20

ESP Control Room - Granolithic floor with non metallic floor hardener in pump houses and Vitrified tiles in AC Areas

Bidder understands that Vitrified Tiles to be given in AC Areas and Granolithic Floor with non-metallic hardener in other areas. Pump houses are Confirmed. not relevant to ESP Control Room. Please confirm.

74

Vol-VI/ Ch-17

Table 1

20 of 20

Granular Finish Paint External

Granular Finish Specification in the tender document is missing. Owner is requested to furnish the same.

ViNERATEX has been mentioned.

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Section / Part / Chapter / Volume Vol-VI/ Ch-17

Clause No. 11.2

17.7.8

76

Vol-VI/ Ch-14

Vol-VI/ Ch-17

14.14

17.4 (d)

Page no. 5 of 16

11 of 20

13 of 23

3

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Referred clause 11.2 for Glazing provision in CCR and CER is contradicting Main entrance to control room shall be provided with air locked with description mentioned in Cl 17.7.8. Bidder shall follow Cl 17.7.8. Please lobby with automatic closing sliding glass doors. Lobby shall be formed of anodized aluminium framing with toughened sheet glass confirm. 6 mm thick. Partition between control room and adjoining rooms shall be of glazed aluminium partition with 300 mm high brick wall at bottom for toe protection. All the doors shall be single leaf glazed aluminium doors for all cabins. For movements of panels suitably sized double leaf aluminium glazed doors shall be provided. Control room wall upto the false ceiling level shall be of aluminium glazed partition on either side of air lock. In other area cladding shall be of brick wall. UPS room shall be provided with brick cladding all-round to reduce sound nuisance. Main entrance of the control room and control equipment room shall be provided with air-locked lobby with provision of double doors / glazed panels of aluminum frame work with toughened safety double glass glazing confirming to IS 2553 hermitically sealed and separated by 12 mm thick cup for thermal insulation. Doors shall be of double swing type or sliding type. Roof Details Roofs of all M. C. C./control rooms, penthouse / JT’s / Crusher House etc., shall have roof water proofing treatment. Roof water proofing treatment shall be as follows: 1) Application of polymerised mastic over the RCC roof to achieve smooth surface as primer coat. All roofs shall be provided with water proofing treatment using high solid content liquid applied elastomeric water proofing membrane with separate wearing course as per ASTM C-898. Thickness of the membrane shall be a minimum of 1.5mm. The treatment includes application of polymerized mortar over sloped roof to achieve a smooth surface and a primer coat. Wearing course shall be 40mm screed of 1:2:4 concrete as above cast in panels of 1.2m x 1 2m and reinforced with 0 56mm dia galvanized chicken wire

Owner's Reply

Confirmed.

Roof Water proofing detail is mentioned for Roof with structural slope, but there is no mention of Water proofing for Roofs without structural slope. In clause 14.14, roof treatment details for non-sloped roof is mentioned for CHP Buildings. Based on the above details and standard industrial practice it is recommended that specification clause is revised to the following (for non sloped roof):

Specifications as per clause 14.14 to follow.

a. Screed (1:2:4) of min 25 mm thick over RCC slab for roof gradient of 1:100. b. 15mm thick cement sand mortar (1:4) for creating smooth surface. c. Elastomeric membrane d. 20 mm thick Cement sand (1:4) with chicken wire mesh. e. Chequered tile in pathways.

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78

79

80

81

Section / Part / Chapter / Volume Vol-VI/ Ch-6

Clause No. 6.14

Page no. 6 of 9

Vol-VI/ Ch-14

14.15

13 of 23

Vol. VI/ Ch 11

11.13.3

12 of 16

Chapter 14 / Volume VI

14.2

4 of 23

Plinth Protection All buildings shall be provided with 1000 mm wide and 100 mm thick PCC of grade M-20 for plinth protection all round with surface drain of required size and slope to suite storm water quantity.

All buildings (including reclaim hopper, penthouse, MCC rooms, pump houses, transfer houses and crusher house) and ground conveyors shall be provided with 750 mm wide plinth protection all around. It consists of 50 mm thick P.C.C. M-20 grade with 12 mm maximum size aggregate Pipe racks and cable racks

14.3

6 of 23

Chapter 14 / Volume VI

14.4

6 of 23

In Crusher house, contractor shall have option to use tubular steel sections for bracings only.

Chapter 23 / Volume VI

23.1

1 of 3

Type -I, Type - II and Type -III roads

In all transfer points contractor shall have option to use tubular steel sections for bracings only.

General NIT drg no. 111-2914.13.1 0200 and Chapter 14 / Volume - VI

10 of 23

Statement of Prebid Queries & Clarification

Plot Plan drawing and Drainage system

Owner's Reply

Bidder proposes to provided 750 mm wide 150 thk PCC plinth protection as per clause 14.15. Please confirm.

In CHP area 50 mm thk 750 mm wide. In other areas as per clause 6.14.

Please clarify the requirement of connecting from existing station and existing pipe racks.

Pipe racks for all connections from the existing station, existing pipe racks is to be used with necessary modification (or) new rack is to be erected Cross beams at floor level supporting conveyor stringer beams Bidder proposes that in addition to ISMB, ISMC or plate girder, wide flange shall be made of single rolled steel beam or single channel section sections e.g Jindal sections can also be used for cross beams. Please (ISMB or ISMC) or plate girder. confirm.

Chapter 14 / Volume VI

82 83

Bid Specification Stipulation

There is no existing structure.

Confirmed.

Bidder proposes to use tubular steel sections in the following areas - a) main gantry truss , top chord & bottom chord bracings & truss members of the conveyor galleries , b) cable gallery and trestles. Please confirm. Bidder to comply with stipulation of technical specification.

All approach roads to the individual buildings in the CHP area shall be provided with Type -III roads . Please confirm.

Confirmed.

As railway siding is in Owner's scope, Bidder understands that drainage In Bidder's scope. system for railway siding area are excluded from Bidder's scope of work. Please confirm. a) Approach to the underground structures like Track hopper, Wagon tipplers and the JT-1 may please be indicated in the drawing in order to bring all the bidders at par. b) Please also clarify the drainage arrangement Further detailing shall be in this area along with the interface of the railway side drains. done during detail engineering stage.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

84

NIT drg no. 111-290200

-

-

Coal Shed CSD-1A & CSD-1B

85

NIT drg no. D-0444111-23-5207

-

-

Conveyor 5A/B crossing the railway tracks

86

Chapter 14 / Volume VI

14.2

4 of 23

It should be Agreed . that for structural design, unit weight of coal shall be assumed as 1100 Kgs. / Cu. M. instead of 800 Kgs. / Cu. M. considered for system sizing purpose.

14.17

15 of 23

Unit weight of coal shall be taken as 1200 Kgs. / cum. for design purposes.

Statement of Prebid Queries & Clarification Two nos coal stock pile shed have been indicated in the plot plan but no details (in terms of specification size or cross section) are available in the NIT. Please clarify with detailed specifications, size and necessary cross sections. Please clarify the drainage arrangement for the trestles (in-between the railway tracks) of this conveyor gallery along with the interface of the railway side drains

Owner's Reply Further detailing shall be done during detail engineering stage. Further detailing shall be done during detail engineering stage.

Contradiction in clause. Owner to specify which clause to be followed for unit weight of coal for design for structural design? Clause 14.17 shall be used for unit weight of coal.

87

Chapter 09 / Volume VI 9.2

2 of 23

The design of steel structures shall ………. by working stress All clauses specified in tender specification are pertaining to IS:800-1984.The method. Design shall be ………of IS 800 (latest) and other relevant latest code for steel structure design is IS-800 - 2007. Please clarify. standards. Follow latest code.

88

Chapter 14 / Volume VI 14.18

17 of 23

For metal roofing and side cladding , the spacing of purlins / rummers ….…….deflection of metal sheet used is limited to Span/250.

Chapter 09 / Volume VI 9.3.1 (d)

3 of 23

If the design of steel structures are done using IS 800-2007 (latest) the allowable deflection criteria for purlins and side runners will be as per Table 6 of the IS code. Confirmed. The allowable deflection of the metal sheet shall be as per manufacturer's recommendations. Please confirm.

For roofing and cladding components - Span / 325. 89

90

91

Drg no. D-0444-11123-5208 & 5201

-

Volume -III, Mechanical works

18.3.14, a.

Volume -III, Mechanical works

3.08

-

Location of conveyor supporting trestles

We understand that the arrangement of vertical bracings for the 4L trestles, no. of trestles shown in the drawings are all indicative. Actual location of the trestles & the arrangement of the vertical bracings (for the 4L trestles) will be decided during detailed engineering. Please confirm

sheet 13 For each gear box, oil level gauge/dipstick, thermometer pockets of 21 with thermometers shall be provided external to the fan stack.

We presume that Temperature elements have to be provided in the gearbox for measuring oil temperature and hence thermometer will not be required separately. Please confirm.

sheet 21 Datasheet of cooling tower, Distribution pipes MOC is mentioned of 21 as Fibreglass reinforced plastic.

Please clarify "Fibreglass reinforced plastic" denotes which pipe?

Confirmed.

Confirmed.

Distribution pipes.

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Section / Part / Chapter / Volume Volume -III, Mechanical works

Clause No. 18.1

Page no. sheet 3 of 21

1.09 93

94

sheet 19

Volume VII, Layout

Volume II, Chapter 1

1

5 of 12

95

Volume VI, Ch 02

2.6 d)

Sheet 2 of 11

96

Volume VI, Ch 02

62 xi)

Sheet 7 of 11

97

Volume VI, Chapter 11 11.12.1

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

TThe cooling tower shall be designed for the ambient wet bulb temperature of 28.0°C. Minimum value of this recirculation correction factor shall be 0.5 0C or as per relevant CTI standard.

Induced Draft Cooling Tower shall be designed considering WBT 28 deg C + recirculation allowance of 0.5 deg C as mentioned in the specification. Please confirm.

Plot Plan Notes Outdoor type 33 KV/11 KV Substation at Make up water pump house

No details (specification and drawings) are available regarding power source and substation required for Make up water pump house. Hence Owner to furnish the following details: a) Location of substation b) Route survey/details for transmission lines/cables c)Land Acquisition/Right of Way, Tree cutting and Approval from statutory authorities shall be included in Owner's scope. Please confirm

Bidders are to note that one (1) more unit of 660 MW may be added in future by the EMPLOYER as an expansion unit for possible augmentation of the station. For this purpose, the employer envisages suitable space provision to be kept for one (1) 660 MW future expansion unit to be integrated along with that of the present two (2) nos. 660 MW units, which are shown in the indicative Plot Plan (Refer Volume - VII). As such suitable provision shall be kept by the bidder in various Civil, Mechanical... sub-sections /parts / chapters of the technical specification (Volume II to VII).

a) Owner to note that tender specification for Civil and Structural works (Volume VI) do not specify any scope of work regarding future expansion. In order to make all bidders at par, Owner is requested to specify provisions to be kept in Civil/Structural buildings, if any, for future expansion.

Owner's Reply

Confirmed.

b) With reference to the aforesaid statement, bidder shall consider future expansion as furnished in mechanical section. Please confirm.

a) Near Intake pumphouse. b Drg enclosed. c) In Owner scope. Tree cutting in Bidder's scope.

a) Only spare provsion. b)Confirmed. c) All roads as shown in Plot Plan are in bidder's scope of work.

c) Construction of Road, fencing, paving, drains and any other associated works for future expansion are excluded from Bidder's scope of work. Please

Owner is requested to furnish area grading layout drawing which will indicate Grading of entire plant area exluding township & the boundary within which area grading to be considered by bidder. Administrative block area are in Bidder's scope. All temporary roads and approach roads necessary for construction Temporary roads are mainly for the use of bidder and its subcontracted purpose shall be of WBM for a minimum width of 4m. agencies, Owner is requested to allow bidder to decide the width and specification of temporary roads. Agreed . Site levelling comprising of earth cutting/filling excluding in the township area, administrative block.

sheet 10 Service building: of 16 Seating accommodation for senior O&M executive along with supporting staff including furnitures of latest style.

In order to keep all bidders at par, Owner to furnish the following information pertaining to service building: a) Number of occupants b) List of furniture including their type, make and numbers c) Additional items like printer, LCD display, water coolers etc. to be explicitly mentioned, if required.

a) 2000 M2 area in 4-5 stories shall be included in Bidder's scope. b&c) Excluded from Bidder's scope.

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Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter 11 11.12.4

Page no.

Bid Specification Stipulation

Sheet 11 Workshop of 16 The building shall house electrical, mechanical workshops and shall comprise the following facilities as a minimum requirement.

Statement of Prebid Queries & Clarification

Owner's Reply

Owner is requested to specify the dimensions of workshop building to be considered by bidder, in order to bring all bidders at par.

Mechanical workshop – consisting of carpentry, Machine shop (for lathes, drilling machines, grinding machines etc.) ,Fabrication / welding and store. Refer addendum-01

a) Electrical room b) Offices, rest room and toilet c)Heavy vehicle shed d) Dozer shed The workshop building area shall be based on the equipment layout during detail engineering. 99

100

Volume VI, Chapter 11 11.12.6

Volume VI, Chapter 11 11.15.1

Sheet 11 Canteen Owner is requested to specify the dimensions of canteen building to be of 16 A canteen building shall be provided for all personnel working in considered by bidder in order to bring all bidders at par. the power plant area. The Canteen Building will be able to cater for minimum 300 persons with staggered meal times in four group with an interval of 30 minutes. Seating arrangement of at least 100 persons shall be made. The following facilities shall be provided in the Canteen as a minimum requirement. Sheet 14 The above capacity will be generated partially by excavating the of 16 area to a specified bottom level of the Reservoir and partially by the formation of embankment with CI/CL type of soil obtained from excavation or from the borrow pit out side the plant area. Preferably, a RCC partition wall will be constructed to divide it into two compartments for cleaning of accumulated silt. Obviously each compartment of the Reservoir will be fed separately.

Refer addendum-01

Earthen wall is shown in the raw water reservoir plan drawing within the tender plot plan drg no.111-29-0200, R0. Bidder shall consider partition wall of earthen embankment instead of RCC. Please confirm. Partition wall not required.

Plot Plan - Drawing No. 111 - 29 - 0200, R0 101

Volume VI, Chapter 23 23.1

sheet 1 of 3

Road leading to main gate of power house building from main entry of plant shall be double lane road with raised 1.5m wide central divider. Minimum thickness of road shall be 25 cm and width of 7.5m each (Total width of road including side shoulders and central divider will be 21.5m).

Power house building vicinity shall be paved with RCC whereas the referred spec is indicating the bidder to construct 21.5 m wide road including central divider upto road leading to main gate. Please follow Plot Plan Bidder is unable to understand exact extent of this 21.5 m wide double lane with Road widths indicated. road. Hence, Owner is requested to provide the mark-up for double lane road in the plot plan so that all bidders are at par.

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103

Section / Part / Chapter / Volume Volume III,Chapter18

Volume III,Chapter18

Clause No. 18.3.1,e

18.3.6,b

Page no. Sheet 7 of 21

Sheet 9 of 21

104

Volume III,Chapter18

18.3.6,b

Sheet 9 of 21

105

Volume III,Chapter18

18.3.6,c

Sheet 9 of 21

106

Chapter 17 / Volume VI 17.7.1 (b)

107

Chapter 14 / Volume VI 14.7 , 14.8 & 14.9 Chapter 06 / Volume VI 6.11

5 OF 20

Bid Specification Stipulation A vibration limit switch of approved make rated at 240V, 8 amps AC continuous for each cell shall be provided

One (1) - locally mounted industrial type, brass encased, mercury in glass, red mercury and black etched stem type thermometers shall be furnished….

2 of 23

As per Bidder's Standard practice, Vibration Sensor (4-20mA) shall be provided instead of Vibration Switch. Through vibration switch, bidder will not be able to measure exact vibration reading. Whereas , Vibration Sensor will give exact vibration level. Please confirm.

Mercury in Glass type Thermometer became obsolete in the market. Hence, bidder shall provide Gas-filled Thermometer for temperature measurement, which is also industrial proven practices. Please confirm.

Owner's Reply

Confirmed.

Confirmed.

Thermometer..each located at each of the cell vertical steel hot water risers to measure hot water temperature along with remote indication in the cooling tower control panel.

One(1) no. Thermometer at each side of Vertical Common Header is sufficient for measuring the Hot Water Temperature. Measurement of Temperature at entry of each cell is not required, since the temperature will be same throughout the Header. Confirmed. Hence, bidder shall provide One(1) no. RTD for remote indication & One(1) no. Temperature Gauge for local Indication at Hot Water common header of each side . One (1) - 150 mm dia dial pressure gauges..each located at each One(1) no. Pressure Gauge at at each side of Vertical Common Header is of the cell vertical steel hot water risers to measure the hot water sufficient for measuring the Hot Water Header Pressure & local Indication. pressure along with remote indication at cooling tower control panel Measurement of pressure at each cell level is not required for operation point of view. Confirmed. Hence, bidder shall provide One(1) no Pressure Gauge at each side of common header for measurement & local Indication. Owner to please confirm acceptance.

Outside plaster on masonary wall - No plastering is required on outside of masonary wall…………….Silicone coating shall be provided on outside exposed face of the brickwall

7 & 8 of Control rooms, MCC bldgs, Pump house & Penthouse - Cladding shall be of brickwork with plastering on both sides. 23 4 & 5 OF Waterproofing of underground structures 9

Chapter 14 / Volume VI 14.1

Statement of Prebid Queries & Clarification

Waterproofing / damp proofing of underground portion of track hopper……….

Please clarify whether any plastering needs to be considered on the outer face & if so, then please mention the thickness of plastering required.

Plastering is required on outer face of masonry walls. Thickness of plastering shall be 18 mm.

There is a variation of the specifications as mentioned in these two different clauses for waterproofing of underground structures. Bidder understands that Confirmed. for coal handling plant underground structures clause no. 14.1 shall be .Bidder's followed. Please confirm. understanding is correct.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Owner's Reply

108

Chapter 17 / Volume VI Table - 1

20 of 20

Architectural works for Transfer Towers - Ceiling paint - Acrylic washable distemper

Bidder proposes to consider metal deck sheet as permanent shuttering for all RCC floors of transfer towers & Crusher house (except crusher supporting deck slab) hence, it will not be possible to apply plastering and painting on Confirmed. the ceiling of structural floors. Please confirm.

109

Chapter 21 / Volume VI 21.4

3 of 11

Coal pile area run-off will be led to settling pond. RCC settling pond with two ………….

Please clarify whether the RCC settling ponds will be designed as un-cracked Cracked sections with 0.1 sections or as cracked sections with limitations in crack width to 0.1 mm on mm limit. both faces.

110

Volume VI

06 of 11

a) Free vibration analysis A free vibration analysis of the fan supporting structure including the intermediate supporting structure for motor, gearbox and pillow block (I applicable) shall be carried out to calculate the natural frequency of the fan supporting structure and its fundamental natural frequency shall be at least +20% away from the operating speed of the fan and motor.

Bidder request to modify the clause as mentioned below: ..the natural frequency of the fan supporting structure and its fundamental natural frequency shall be at least ± 20% away from the operating speed of the fan and motor.

111

112

113

Volume VI

13.8.2 (ii)

13.8.6

08 of 11

Vol VII, Layout

Design of RCC structures of cooling tower which are not in contact Bidder propose to design the structures in contact with water / water spray / with water / water spray / moist air shall be carried out generally as moist air, excluding CW basin as per limit state method based on IS:3370 per IS:456, Code of practice for plain and reinforced concrete for by limiting the crack width as per IS: 3370. Please Confirm. general building construction. The basis for design of all RCC structures shall be as per working stress method of design as outlined in IS:456. However, all other structures in contact with water / water spray / moist air, excluding CW basin shall be designed as per working stress method based on IS:456 for concrete but the stress in reinforcement steel shall be limited to the values as given in IS:3370.

Plot Plan - Raw water reservoir

Volume VI, Chapter 11 11.15.1

14 of 16

Volume VI, Chapter 11 11.2

sheet 5 of 16

Agreed .

No partiton is shown in the raw water reservoir layout mentioned in the Plot Plan. Owner to clarify whether it is mandatory for the Bidder to consider two compartments in raw water reservoir?

Preferably, a RCC partition wall will be constructed to divide it into two compartments for cleaning of accumulated silt. Obviously each compartment of the Reservoir will be fed separately Under deck insulation shall be provided on the ceiling, on the walls Bidder shall provide under deck insulation based on functional requirement and beams above false ceiling. Under deck insulation shall be (as per approved layout). Please confirm. provided for air washer room also.

Bidder to comply with stipulation of technical specification.

Two compartments to be considered as per Specification.

Bidder to comply with stipulation of technical specification.

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115

I

Section / Part / Chapter / Volume

Clause No.

Volume VI, Chapter 11 11.2

Volume VI, Chapter 9

9.2

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

sheet 3 of 16

Roofing shall consist of in-situ RCC slab of minimum 150 mm thickness laid to a slope of 1 in 100, constructed over permanently colour coated galvanized MS troughed metal sheet of approved profile supported on steel purlins and trusses.

Bidder proposes to provide minimum 40 mm thick slab. Please confirm

sheet 2 of 23

Roof decking sheets shall be designed as per IS:801 to carry the self load, dead load due to RCC slab and finishes and imposed load. The deflection of metal deck shall be limited as per BS:5950.

Bidder shall design roof decking sheet to carry the self load, dead load due to green concrete and 100 kg/sq.m construction live load.

Owner's Reply

Bidder to comply with stipulation of technical specification.

Confirmed.

SG_QA, Erection and Others General Queries

Vol II / Ch 1 : Intent of Specification

1.0

1

Vol III / Ch 1: SG & Auxiliaries / Section 1 : Scope

1.13.10

Bidders shall note that one (1) more unit of 660 MW may be added in future by the EMPLOYER as an expansion unit for possible augmentation of the station. For this purpose, the employer envisages suitable space provision to be kept for one (1) 660 MW future expansion unit to be integrated along with that of the present two (2) nos. 660 MW units, which are shown in the indicative Plot Plan (Refer Volume - VII). As such suitable provision shall be kept 5 of 12 by the bidder in various Civil, Mechanical, Electrical and C&I systems of present 2x660 MW units for future augmentation/integration & interconnection of corresponding system & facilities with the present units as brought out in various subsections/ parts/chapters of the technical specification.

Kindly note that most of the Steam Generator auxiliaries are unitized in nature. Ammonia unloading, storage and handling system is the major system which is common for both units. Bidder shall design this system common for two units as per tender specification requirement without keeping any provision for any future unit. In order to make all bidders at par, bidder would request SJVN/DESEIN to specify the systems/equipment for which space provision is to be kept considering future unit provision. Agreed for Ammonia unloading system shall be designed for 2 units.

Ammonia Unloading, Storage and Handling System (Common for all units) i) A common ammonia unloading, storage and handling system 45 of 47 shall be provided having a handling capacity equivalent to SCR Systems of two (02) units. The above ammonia unloading, storage and handling system shall be designed for Anhydrous Ammonia.

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Section / Part / Chapter / Volume

Clause No.

Page no.

Bid Specification Stipulation Pre-commissioning and commissioning activities:

2

Vol II / Ch 1 : Intent of Specification

4.2

The contractor's scope shall include all pre-commissioning and commissioning activities, materials and services as detailed in other portion of technical specifications including supply of all 9 of 12 consumables (except coal and fuel oil for firing), temporary equipment and piping, instruments, labour/skilled manpower's etc. The scope includes complete requirement of flushing oils including fresh oil refilling during the pre-commissioning and commissioning activities and subsequent initial operation. Special Tools & Tackles and Test/Measuring Equipment

3

Vol II / Ch 1 : Intent of Specification

4.2

4

Vol II / Ch 2 : Project Information

-

5

6

Volume III / Ch 16 : DMCW System

Volume III / Ch 1: SG & Auxiliaries / Section 2 : Design Basis of SG & Auxiliaries and SCR

All soft wares provided shall necessarily include the cost for 10 of 12 perpetual license(s) for use on all the machines and an Annual Maintenance Contract (AMC) which shall include software upgrades as & when released by the software agency for a period of three (3) years after warranty/guarantee period. Climatological Table

16.11

2.1.18.

Statement of Prebid Queries & Clarification Bidder would like to inform that other items are also excluded during precommissioning work, Hence the clause shall be modified as below. The contractor's scope shall include all pre-commissioning and commissioning activities, materials and services as detailed in other portion of technical specifications including supply of all consumables (except coal and fuel oil for firing, Anhydrous ammonia, Chemicals etc), temporary equipment and piping, instruments, labour/skilled manpower's etc. T............

The provison as per Bidding specification shall prevail.

Bidder would like to inform that the requirement is quite exhaustive. Bidder would like to confirm that all the softwares provided on the machines shall be latest. Any AMC requirement after warranty period on the same shall be The Provision as per taken care by customer directly. Customer to kindly confirm. Bidding specification shall prevail.

Climatological table provided is for Chapra, Kindly clarify the same.

7 of 7 DMCW System Description 16.11.1 The DMCW pumps shall operate in closed piping system and shall pump DMCW water to respective SG, TG & BOP 8 of 12 auxiliaries through primary side of PHE’s. Refer P & ID of DMCW system (Dwg. No. 111-12-3310).

Owner's Reply

Refer Ammendment -04 for revised climatological for Dehri.

The P&ID of DMCW system mentioned in this clause in not available in tender specification. Kindly provide the same. Attached. Drg No. 111-123201 to be referred.

Bidder shall provide O&M manual and Customer's representative shall Capital Overhaul of Steam Generator Purchaser envisages to carry out the capital overhaul of unit once operate steam generator in line with the guidelines provided in O&M manual. Customer shall be responsible to any variation/ violation of O&M guidelines. Bid specification is clear. in three (3) years. The design and materials for various equipments/auxiliaries etc. shall be selected by the Bidder keeping Bidder to follow the 9 of 120 in view the above requirement of the customer, such that no major specification. repairs/replacements, requiring shutdown of the unit, are needed in between the capital overhauls.

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Section / Part / Chapter / Volume

VOLUME-I / SECTION – IV

Clause No.

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Page no.

Bid Specification Stipulation

“Installation Services” means all those services ancillary to the supply of the Plant and Equipments for the Facilities, to be provided by the Contractor under the Contract; e.g., transportation and provision of marine or other similar insurance, inspection, expediting, Site preparation works (including the provision and use of Contractor’s Equipments and the supply of all construction materials required), installation, testing, pre-commissioning, 2 of 62 commissioning, operations, maintenance, the provision of operations and maintenance manuals, training, etc.

Statement of Prebid Queries & Clarification

Owner's Reply

We would like to clarify that the Operations & Maintenance activities of steam generator unit (till the handover of unit) shall be take care by Customer's representative/personnel under bidder's supervision/guidance. Hence, we propose to modify this clause as below: “Installation Services” means all those services ancillary to the supply of the Plant and Equipments for the Facilities, to be provided by the Contractor The Provision as per under the Contract; e.g., transportation and provision of marine or other Bidding specification shall similar insurance, inspection, expediting, Site preparation works (including prevail. the provision and use of Contractor’s Equipments and the supply of all construction materials required), installation, testing, pre-commissioning, commissioning, operations, maintenance, the provision of operations and maintenance manuals, training, etc.

Pulveriser Queries

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Volume III, Mechanical Works, Ch 1

1.1.15.3

Each pulveriser shall be complete with all wear parts/ grinding elements and shall be provided with platforms around the pulveriser, lubrication systems (comprising of 2x100% pumps, 2x100% coolers and 2x100% filters for each pulveriser, 2x100% Hydraulic System (if applicable), drive motors, auxiliary gear, instrument tapping points and other equipment necessary for safe Page 16 and efficient operation of pulveriser. of 47

Bidder would like to clarify as follows: Each pulveriser shall be complete with all wear parts/ grinding elements and shall be provided with platforms around the pulveriser, lubrication systems (comprising of 2x100% pumps, 2x100% coolers and 2x100% filters for each pulveriser, 2x100% pump for Hydraulic System (if applicable), drive motors, Gear Unit , instrument tapping points and other equipment necessary for safe and efficient operation of pulveriser.

The Provision as per Bidding specification shall prevail.

Please Confirm.

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3

Volume III, Mechanical Works, Ch 1

Volume 1, section III,

2.10.5.3- I

10-b

The classifier vanes shall be adjustable externally and shall be lined with approved wear resistant material to ensure the Page 37 guaranteed wear life. of 120

Bidder would like to clarify as below, Please Confirm.

Coal Pulveriser Grinding elements Wear life : The guaranteed wear life for the grinding elements of coal pulverisers offered shall Page 52 not be less than 6000 hrs for whole range of specified coal(s). of 63

Bidder would like to inform that there is ambiguity in the different clauses of the technical specification. For Example, Minimum Guaranteed Life of Coal Pulverizer Wear Parts as per Volume III, Mechanical Works, Ch 1, clause 2.10.5.15 Specify min. life of 8000. Request to obtain the clarification.

Classifier vanes are fixed type & no external adjustment is possible. Classifier will be provided with Variable frequency drive for speed control & fineness control.

Agreed. The Provision as per Bidding specification shall prevail.

8000 hours.

Please confirm us the same.

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Clause No.

Page no.

4

Volume II, ch 2: Project Information

Appendix- II:

Page 5 of 7

Bid Specification Stipulation YGP (mg/kg), Moisture( %) & ash( %) are not provided in the Coal quality parameters.

Statement of Prebid Queries & Clarification Please note that the YGP index of the coal is not provided in the tender specification, we will request you to kindly provide the same.

Owner's Reply Revised cpal analysis shall be provided with ammendements.

Pulveriser - QA queries Raw material for shaft, coupling, gears and pinions, top and bottom Bidder would like to clarify that Forged shafts used in Roller Journal races and other rotating components shall be subjected to UT. Assembly / Tensioning Parts Assembly shall be subjected to UT & MPI, as MPI/LPI shall be carried out to check surface soundness. applicable, during stages of production.

1

Volume II General & Schedule Ch 11 QAP

2

Volume II General & Schedule Ch 11 QAP

3

Volume II General & Schedule Ch 11 QAP

4

Volume II General & Schedule Ch 11 QAP

2.5

2.5

2.5

2.5

However, Shaft, Coupling, Gears & Pinions, Top & Bottom races and other rotation components are the part of bought-outs viz., Gear Box with Lubrication units, Roller Loading Device etc. these are compliant to supplier internal quality norms & no reports for UT/MPI/LPI will be produced.

Page 453 of 1318

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Page 453 of 1318

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The Provision as per Bidding specification shall prevail.

Wear-resistant parts shall be UT/ RT tested to check soundness after suitable heat treatment. Check for chemical composition, hardness and microstructure shall be carried out. For ceramic materials check for various properties including hardness, density, wear rate and composition shall be carried out.

Bidder would like to clarify as follows:

Butt welds in the tube/ separator /body casing of the mill shall be tested by RT and MPI. All other welds in main tube/separator shall be tested by MPI/LPI for acceptance. The tube shall be statically balanced.

The mill casing inside is subjected to pressure of 700 mmWC (0.07barabove atmosphere) which is very low; hence Butt weld shall be subjected to UT after PWHT, as applicable & RT shall not be applicable.. However, MPI for fillet welds is not possible considering positional difficulty; hence LPI is proposed.

The Provision as per Bidding specification shall prevail.

All gearboxes shall be run tested for adequate duration to check rise in oil temperature, noise level and vibration. Check for leak tightness of gear case also shall be performed.

Bidder would like to clarify as follows: Trial run duration shall be as per manufactures specification (approved by Bidder-Engg). Oil leakage shall be checked during no load trial run test at supplier's works as per supplier's standard practice.

The Provision as per Bidding specification shall prevail.

Wear resistant parts viz. Roller Liners used in Roller Journal Assembly & Table Liners are composites comprising of SG Iron & Hi chrome material. For such composite material, UT/RT/MPI is technically not feasible. However, The Provision as per PT shall be conducted to ensure surface integrity. (PT acceptance norms will Bidding specification shall be as specified by the supplier specification & approved by Bidder Engg). prevail.

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Clause No.

Volume II General & Schedule 2.5 Ch 11 QAP Volume II General & Schedule 2.5 Ch 11 QAP Quality Assurance Queries QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO I. Separator (d) N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO I. Separator (j) N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO I. Separator (k) N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO II. Header (b) N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO II. Header (c) N M1 : STEAM GENERATOR & AUXILIRIES

Page no. Page 453 of 1318 Page 453 of 1318

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Fabricated pipe welds should be examined by MPI.

In case of Pulveriser mill, pipe welds are applicable only for Lower housing – seal air arrangement. This is a low pressure piping & hence LPI is proposed.

Trial assembly (stacking) of at least two Mill complete with all major components needs to be carried out at shop.

Bidder would like to clarify that Trial assembly will be done at shop, only One The Provision as per Mill will be trial assembled with 01 no. Grinding Table, 01 no. Roller Journal Bidding specification shall Assembly, 01 no. Lower Housing and 01 no. Middle Housing. prevail.

Fully machined connecting pieces of internal diameter 100mm and Bidder would like to propose to use PT or MT only. above, shall be subjected to magnetic particle examination. Page 2 of 94

All full penetration welds shall be subjected to ultrasonic examination after stress relief.

Agreed. Bidder propose ,maximum area shall be covered in case full coverage is not possible due to inaccessibility.

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Page 3 of 94

After stress relieving (SR) all welds, internal and external shall be Bidder propose , after stress relieving (SR) all welds, internal and External examined by MPI methods depending on size and accessibility and shall be examined by PT or MT methods depending on size and all butt welds shall be subjected to 100% radiography. accessibility. In case MT is not accessible. PT shall be done. Agreed for Radiography -100 % All butt welds shall be subjected to RT examination. Also MPI after Agreed For RT. SR. Bidder propose to use MT/PT for Header butt joints after S.R

Page 3 of 94

All full penetration nozzle and attachment welds shall be subjected Full penetration nozzle UT : Agreed subjected to accessibility. to UT prior to stress relieving. For Attachment : Bidder propose to use MT/PT. Page 3 of 94

Owner's Reply The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail. PT

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

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Section / Part / Chapter / Volume QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES

Clause No.

II. Header (d)

II. Header (e)

Page no.

Page 3 of 94

Page 3 of 94

Bid Specification Stipulation All nozzles, branches, stubs and load bearing attachment shall be examined by MPI techniques after the toes of the weld have been ground smooth and stress relieved.

QUALITY ASSURANCE PLAN FOR III. Tubes & MECHANICALSECTIO Tube Elements N M1 : STEAM (c) GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN III. Tubes & FOR MECHANICALSECTIO Tube Elements (f) N M1 : STEAM GENERATOR & AUXILIRIES

Bidder propose to carry out PT or MT. When MT is not accessible/feasible PT shall be done.

Non-load bearing welds shall be examined by MPI techniques after Bidder propose to use PT or MT Non-load bearing weld the toes of the welds have been ground smooth and stress relieved.

Headers shall be subjected to hydraulic pressure tests and all compensating pads to be pneumatically tested. II. Header (f)

Statement of Prebid Queries & Clarification

Bidder propose to carry out Hydrotest for closed end headers only as per IBR approved drawing.

Page 3 of 94

Owner's Reply

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

All tubes/stubs/panels/coils shall be checked for clearance by steel Bidder would like to clarify as follows: ball test and for cleanliness by sponge passage. Ball and sponge pass test shall be performed considering feasibility. For Coils : Ball & Sponge pass Agreed.

Page 4 of 94

Page 4 of 94

For WW panel : Due to 3D opening, Y piece not feasible in some panels.

Tubes and fabricated panels/coils shall be subjected to hydraulic pressure test excluding loose tubes but including burner panels, reheaters, superheaters & economizers.

The Provision as per Bidding specification shall prevail.

Similarly as per our recent project, Bidder Propose to perform Random-10 % Hydro test for each type : reheaters, superheaters & economizers, Flat & The Provision as per bend panel. Bidding specification shall Burner Panel : 100 % considering critical welding and manufacturing prevail.

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Section / Part / Chapter / Volume QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES

Clause No.

III. Tubes & Tube Elements (h)

Page no.

Page 4 of 94

Bid Specification Stipulation

IV. Boiler Piping (d)

IV. Boiler Piping (g)

IV. Boiler Piping (g)

IV. Boiler Piping (h)

Bidder propose 100 % PT/MT for bend area for hot bending. For Cold bending random PT/MT can be done.

Page 4 of 94

Page 4 of 94

The edge preparation for shop and site welds in stainless steel /alloy steel shall be subjected to a dye penetrant check. Nondestructive examination of welds shall be carried out after post weld heat treatment, if any.

Bidder have not envisaged PT for all WEP of SS & AS Pipes. However PT-100 % can be performed for WEP of P91/92 materials only.

All load bearing attachment welds shall be subjected to MPI after SR.

Bidder propose to carry out PT or MT. When MT is not accessible/feasible PT shall be done.

All butt welds in alloy steel piping of P91, X20 and X 22 shall be checked for RT/ UT and MPI after SR. UT shall be of Digital Recordable Type.

Bidder clarify that , Bidder would like to apply RT/digital recordable type of UT for all alloy /CS steel boiler piping same as our recent project.

Temperature > 400 Deg, C and/or pressure exceeding 71 bar. 100% RT/UT on butt welds and full penetration branch welds

For UT on Full penetration Joints : Maximum area shall be covered in case of full coverage is not possible due to inaccessibility during UT of full penetration nozzle. UT Shall be conventional UT (NOT digital UT for full penetration nozzle)

If grinding method is used for making WEP (Weld Edge preparation) , PT examination can be applied to check surface defect.

Page 4 of 94

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Page 5 of 94

Owner's Reply

Two exposures for each weld shall be taken wherever there is no limitation in In case of RT of tube welds with DWDI (elliptical view) number of carrying out two RT shots. For WW panel two exposure is not practical exposure shall be as per relevant code/ plant standard and will not feasible considering fin welding with tube, openings, and other attachments. The Provision as per be less than two exposures for each weld. Bidder propose to perform 10 % double exposure for tubular weld joints in Bidding specification shall random sampling of 20 %. prevail.

Outer surface of bends shall be subjected to MPI/LPI. IV. Boiler Piping (c)

Statement of Prebid Queries & Clarification

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

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Section / Part / Chapter / Volume QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES

Clause No.

IV. Boiler Piping (h)

IV. Boiler Piping (h)

Page no.

Page 5 of 94

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

Temperature > 400 Deg, C and/or pressure exceeding 71 bar. Temperature > 175 Deg, C upto 400 Deg. C and/or pressure exceeding 17 bar and upto 71 bar. 100 % MPI

Bidder propose to carry out PT or MT. When MT is not accessible/feasible PT shall be done.

Wherever SR/PWHT is envisaged for alloy steel, above NDTs shall be after SR/PWHT.

Bidder propose to carry out these tests before PWHT/Stress Relieve. In case of P91 Piping NDT will be performed as per requirement after PWHT/Stress Relieve For other alloy steel-Gr..12,22 (Except 91 grade) & Carbon steel piping motioned NDE shall be performed before PWHT.

Page 5 of 94

Owner's Reply

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

Butt Welds shall be tested for UT and fillet welds shall be tested for 100% RT/UT on butt-welds of plate thickness > 32 mm for hanger supports MPI. For plates of thickness > 25mm & < 32mm - 10% RT and 100% MT/PT 2.12. Hangers For plates of thickness < 25mm - 10% PT/MT. Page 13 & Supports: for For Fillet Weld : 100 % MT/PT of 94 Rigid hangers

The Provision as per Bidding specification shall prevail.

(a)Hydraulic pressure test shall be carried out on each pipe and expansion bellow. 2.13. Metallic Page 14 Roof Penetration exp joint (small size bellow) Expansion Joint of 94 (if applicable)

The Provision as per Bidding specification shall prevail.

(c)The edge preparation for shop and site welds in stainless steel /alloy steel shall be subjected to a dye penetrate check.

Roof Penetration exp joint bellow Hydro test is not practical , Bidder propose to perform air leak test in lieu of Hydro test.

Bidder have not envisaged PT for all WEP of SS & AS Pipes. However PT-100 % can be performed for WEP of P91/92 materials only.

5.0 POWER Page 16 CYCLE PIPING of 94

If grinding method is used for making WEP (Weld Edge preparation) , PT examination can be applied to check surface defect.

(d) Pipe bend shall be checked for ovality and thinning by ultrasonic or other acceptable methods on first off lot & on random 5.0 POWER Page 16 samples for subsequent pieces for high pressure applications. CYCLE PIPING of 94 Outer surface of bends shall be subjected to magnetic particle examination/LPI.

Bidder propose 100 % PT/MT for bend area for hot bending. For Cold bending random PT/MT can be done.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

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QUALITY ASSURANCE PLAN Page 16 FOR 5.0 POWER & 17 of MECHANICALSECTIO CYCLE PIPING 94 N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN Page 16 FOR 5.0 POWER & 17 of MECHANICALSECTIO CYCLE PIPING 94 N M1 : STEAM GENERATOR & AUXILIRIES QUALITY ASSURANCE PLAN Page 16 FOR 5.0 POWER & 17 of MECHANICALSECTIO CYCLE PIPING 94 N M1 : STEAM GENERATOR & AUXILIRIES Volume II General & Schedule

2.5

Page. 10 of 94

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2.5

Page. 10 of 94

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Volume II General & Schedule

2.5

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Volume II General & Schedule

2.5

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Volume II General & Schedule

(e)Non-destructive examination of welds shall be carried out after post weld heat treatment, if any.

(i)Wherever SR/PWHT is envisaged for alloy steel, above NDTs shall be after SR/PWHT. (h)Temperature > 400 Deg, C and/or pressure exceeding 71 bar. 100% RT/UT on butt welds and full penetration branch welds

(h)Temperature > 400 Deg, C and/or pressure exceeding 71 bar. Temperature > 175 Deg, C upto 400 Deg. C and/or pressure exceeding 17 bar and upto 71 bar.

Statement of Prebid Queries & Clarification Bidder propose to carry out these tests before PWHT/Stress Relieve. In case of P91 Piping NDT will be performed as per requirement after PWHT/Stress Relieve For other alloy steel-Gr..12,22 (Except 91 grade) & Carbon steel piping motioned NDE shall be performed before PWHT.

For UT on Full penetration Joints : Maximum area shall be covered in case of full coverage is not possible due to inaccessibility during UT of full penetration nozzle. UT Shall be conventional UT (NOT digital UT for full penetration nozzle)

Bidder propose to carry out PT or MT. When MT is not accessible/feasible PT shall be done.

100 % MPI Coal Mills, PF Piping and Burners

Raw material for shaft, coupling, gears and pinions, top and bottom races and other rotating components shall be subjected to UT. MPI/LPI shall be carried out to check surface soundness.

Coal Mills, PF Piping and Burners

Wear-resistant parts shall be UT/ RT tested to check soundness after suitable heat treatment. Check for chemical composition, hardness and microstructure shall be carried out. For ceramic materials check for various properties including hardness, density, wear rate and composition shall be carried out.

Page 10 of 94

2.5

27

Bid Specification Stipulation

Coal Mills, PF Piping and Burners

Butt welds in the tube/ separator /body casing of the mill shall be tested by RT and MPI. All other welds in main tube/separator shall be tested by MPI/LPI for acceptance. The tube shall be statically balanced.

Coal Mills, PF Piping and Burners

All gearboxes shall be run tested for adequate duration to check rise in oil temperature, noise level and vibration. Check for leak tightness of gear case also shall be performed.

Coal Mills, PF Piping and Burners

Fabricated pipe welds should be examined by MPI.

Owner's Reply

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail.

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2.5

Page 10 of 94

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2.5

Page 11 of 94

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2.5

Page. 11 of 94

Bidding Doc. No.D0444-4100-01-T-EPC Volume II

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QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES Bidding Doc. No.D0444-4100-01-T-EPC Volume II QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES Bidding Doc. No.D0444-4100-01-T-EPC Volume II

36

VI. Valves (b)

Bid Specification Stipulation Coal Mills, PF Piping and Burners

Ceramic/basalt lined piping/bends shall be checked for proper layout.

Coal Mills, PF Piping and Burners

Weldments on burner components shall be checked with suitable NDT. The burner assembles shall be tested for operation at shop.

Coal Mills, PF Piping and Burners

Trial assembly (stacking) of at least two Mill complete with all major components needs to be carried out at shop.

Hardened/stellitted valve disc and seat are to be subjected to LPI and hardness check.

Bidder propose to carry out these tests on test piece.

The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail.

Bidder propose to carry out colour matching only in the case where valve manufacturer standard procedure include this check..

The Provision as per Bidding specification shall prevail.

Page 6 of 94

X. Steam Generator QUALITY Boiler Start up Page 8 ASSURANCE PLAN Drain Reof 94 FOR circulation MECHANICALSECTIO Pump-Type testN M1 : STEAM g GENERATOR & AUXILIRIES

Owner's Reply

The Provision as per Bidding specification shall prevail.

Page 6 of 94

Color matching of valve disc/plug and seat shall be carried out to ensure min. 80% contact and no through passage.

VI. Valves (c)

Statement of Prebid Queries & Clarification

i. Tests to establish unit functioning of pump at temp and pressure. Bidder propose to review the type test report for same type/model/rating of ii. Hot standstill and start up tests. BCP Pump.

The Provision as per Bidding specification shall prevail.

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Clause No.

Page no.

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Statement of Prebid Queries & Clarification

Owner's Reply

Bidding Doc. No.D0444-4100-01-T-EPC Volume II

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Full range performance test shall be carried out on one fan of each Since BS 848 ,Part-1 is now withdrawn and replaced with EN standard i.e. type and size as per BS 848, Part-1. BS EN ISO 5801:2008, Bidder propose to review the type test report for same Type/model/rating of ID/FD/PA Fan. Also Conductance of full range 2.3 Fans: performance testing at shop is practically not feasible with most of the Induced Draft, QUALITY vendors. We will provide proven fan models with end user certificates, as Forced Draft Page 10 ASSURANCE PLAN available. and Primary Air of 94 FOR fans and GR MECHANICALSECTIO fans -e N M1 : STEAM GENERATOR & AUXILIRIES Bidding Doc. No.DTest for weighing accuracy, calibration and repeatability shall be Bidder propose to review the type test report for same type/model/rating of 0444-4100-01-T-EPC carried out at various speeds by a coal flow on two feeders. coal feeder. Volume II QUALITY ASSURANCE PLAN FOR MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES Bidding Doc. No.D0444-4100-01-T-EPC Volume II

2.6- Coal Feeder (e)

The Provision as per Bidding specification shall prevail.

Page 11 of 94

Ceiling girders/columns, ducts hoppers & tunnels shall be trial assembled and match marked prior to dispatch/erection. At least two consecutive girders along with cross member shall be assembled at a time.

2.11-Boiler QUALITY Structure, Page 13 ASSURANCE PLAN Ducts, Hoppers of 94 FOR etc.-e MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES Bidding Doc. No.Da) Hydraulic pressure test shall be carried out on each pipe and 0444-4100-01-T-EPC expansion bellow. Volume II QUALITY 2.13-Metallic Page 13 ASSURANCE PLAN Expansion Joint of 94 FOR (if applicable)-a MECHANICALSECTIO N M1 : STEAM GENERATOR & AUXILIRIES

Provision as per BSEN ISO:5801-2008. Type test shall be conducted.

Bidder propose to carry out the trial assembly in single girder only i.e. two pieces of girders shall be assembled at shop . As per Bidder's standard practice all the four girders shall be assembled at ground before lifting at site. The Provision as per Bidding specification shall prevail.

Bidder propose to perform pneumatic test for determining leakage in expansion bellow The Provision as per Bidding specification shall prevail.

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Section / Part / Chapter / Volume Bidding Doc. No.D0444-4100-01-T-EPC Volume II

41

Clause No.

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

c) Butt Welds shall be tested for UT and fillet welds shall be tested for MPI.

Bidder propose to carry out RT or UT for butt weld & For Fillet PT or MT as MT is not accessible/feasible PT shall be done.

Boiler light up & Chemical Cleaning completion - 36 TG on Barring Gear 37

As per standard practice, boiler clean-up / chemical cleaning is done before Boiler Light-up. During boiler clean-up / chemical cleaning, TG is required on barring gear for vaccum-up.

2.12-Hangers & Page 13 Supports-c of 94

QUALITY ASSURANCE PLAN FOR Commissioning Queries

1

EPC PACKAGE VOLUME-I, SECTION – III

2

Volume II General & Schedules, Ch 5 : General Technical Requirement

3

Volume II General & Schedules Ch 8 : Functional Guarantee & Liquidated Damages

3

Page 42 of 63, Page 44 of 63

Owner to confirm.

Initial Operation / Trail Operation Test 26.2

2.1.8

Sheet 35 of 91

Owner's Reply

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

Customer is requested to specify the minimum interruption which should be allowed during initial operation / Trial operation test. These interruption may The Provision as per be due to various issues arising during operation such as grid failure, no load Bidding specification shall demand, unavailability of inputs from Customer, etc. prevail.

All instruments required for performance testing shall be of the Bidder would request to kindly clarify that Calibration can be done at any type and accuracy required by the code and prior to the test, the NABL accredited laboratory. Please confirm. Sheet 2 Contractor shall get these instruments calibrated in an independent of 78 test Institute approved by the Employer.

Agreed.

Erection Queries

1

VOLUME-I, SECTION – III

2

VOLUME-I, SECTION – III

3

VOLUME-I, SECTION – III

9

ANNEXURE-A

ANNEXURE-A

Considering the gap of four (4) months between consecutive units, unit wise erection agency deployment program shall be discussed during the pre-award discussion based on the construction 51 of 63 methodology & erection strategy

600/750 MT Crane for lifting of structures, Ceiling girders etc. as per the erection strategy.

Kindly note that bidder has standard practice to lift ceiling girder using strand jacks. Hence, 600/750 MT crane for lifting of structure, ceiling girders, etc. is not envisaged.

Passenger cum goods lift ( 2 Nos Per unit)

Bidder shall provide one no. passender cum goods lift per steam generator unit which is applicable for erection of steam generator as per bidder's standard practice. Please confirm acceptance.

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60 of 63

Bidder shall submit unit wise erection deployment program & erection strategy during pre-award stage stage. However, bidder will depute single erection agency who will be responsible for executing erection activities for steam generator & auxiliaries under bidder's supervision. Kindly confirm.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail.

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Section / Part / Chapter / Volume

4

Volume II General & Schedules/Ch 6 : Erection Conditions of Contract

5

Volume II General & Schedules/Ch 6 : Erection Conditions of Contract

Clause No.

6.1

13

Page no.

Bid Specification Stipulation

Each steam and water tubes shall be blown with compressed air and shall be subjected to ‘ball test’ before erection to ensure that 3 of 48 no obstructions exist

We understand that 'ball test' means sponge ball test. Kindly confirm.

Welds required for holding insulation on pressure parts shall be carried out by 5 of 48 IBR qualified welder.

As per bidder's standard, the insulation pins are welded on the water wall fins. There will be minor requirement of welding at site which shall be done by non-IBR welders. Kindly confirm acceptance.

air/gas tightness test etc. 6

Volume II General & Schedules/Ch11 : QAP(Mechanical)

7

Volume II General & Schedules/Ch11 : QAP(Mechanical)

8

Volume II General & Schedule/Ch10 : Storage of Equipments/ Goods at Site

9

Volume II General & Schedule/Ch10 : Storage of Equipments/ Goods at Site

b)

3.4

23 of 94

On completion of each joint, the welder shall mark his regularly assigned identification mark near the joint. The welder’s identification numbers, inspection stamps or code symbol stamps and any other information shall not 2 of 48 be directly stamped on any alloy steel piping. In alloy steel piping, all such information shall be stamped on separate marking plate which shall be tack welded on pipe near the weld. All materials shall be stored minimum 200 mm above the ground by providing good wooden sleepers.

3.6

4.3.4

Statement of Prebid Queries & Clarification

2 of 10

Semi-Closed Storage: Boiler dampers, manhole doors, mountings, casing frames, buck stays, Air pre-heater frames tubes, baskets. Burner panels and 5 of 10 burners, Electrostatic precipitator shell, discharge and collecting plates.

Owner's Reply

Confirmed.

The Provision as per Bidding specification shall prevail.

Bidder proposes to test all the weld joints in boiler furnace and pressure parts fins by Dye penetration test. The requirement of air/gas tightness test is not The Provision as per envisaged for bidder. All the ducts joints shall be tested by Kerosene test. Hence, tightness test for Bidding specification shall prevail. ducts is also not envisaged for bidder. LMB requested employer joint tracebality shall be maintained as per the OEM standard practice. LMB maintains weld map and ensure complete tracabality with respect to welder no , joint no and date of welding

We understand that bidder may use wooden or, concrete sleepers to store material above ground as wooden sleepers are hazardous in nature. Please confirm.

Kindly note that semi-covered storage is not applicable for these material. Bidder proposes to store these material in open yard. If required, bidder may provide Tarpulin covering. Please confirm acceptance.

The Provision as per Bidding specification shall prevail.

Confirmed.

The Provision as per Bidding specification shall prevail.

Mandatory Spares Queries

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1

Section / Part / Chapter / Volume

General

Clause No.

Page no.

Bid Specification Stipulation

GENERAL NOTE: 3.0

In case spares indicated in the list are not applicable to the particular design offered by the bidder, the bidder should offer spares applicable to Sheet 4 offered of 106 design with quantities generally in line with the approach followed as per the list from Volume - II. Mandatory Spare

2

3

4

General

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

5

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

6

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

1.2

1.00.00

2.17 A

The bidder shall indicate the prices for each and every item (except for items not applicable to the bidders design) in the Sheet 1 ‘Schedule of mandatory Spares’ whether or not he considers it of 106 necessary for the Purchaser to have such spares

Sheet 82 of 106

III. CONTROL & INSTRUMENTATION (MANDATORY SPARES) : Table Heading

Sheet 17 of 106

Sheet 20 of 106

Customer is requested to clarify following understanding : 1. Bidder will consider the price for applicable Item/spares applicable to offered design only. There will be No pass-on / commercial rebate during Contract stage due to any spare not applicable as per bidder/OEM offered design (but indicated in the mandatory list).

Owner's Reply

The Provision as per Bidding specification shall prevail.

Customer is requested to clarify following understanding : If a particular mandatory spare of one System/ Sub-System / Equipment is found to be covered under any other chapters/ sub clause of Volume II General & Schedules, Ch 9 : Mandatory Spares of technical specification, these spares are not required to be repeated. In case of repeated / duplicate Shall be decided during spares, the highest quantity arrived from the calculation of mandatory spares detail engineering stage. from any of the repeated / duplicate clause shall be supplied.

Itemized unit price for mandatory spares is very difficult to indicate during bid submission. We request Owner to kindly delete this specification requirement The Provision as per Bidding specification shall prevail. Bidder understanding is that the quantities mentioned here are for both the units.

Quantities are per unit. In case of common system, quantities shall Kindly Confirm. be doubled. Each type, size and Class above 100 mm : 20% more or 4 nos. Bidder request owner, Inline with current NTPC/State Govt projects to review whichever is More and revise this requirement as Each type, size and Class above 100 mm and below 250 mm : 2 nos. Each type, size and Class above 250 mm : 1 nos. Cyclone Separator - 50% of the quantity being used in one unit

2.29.13

Statement of Prebid Queries & Clarification

As per bidder's standard practice cyclone separator is not required, hence mandatory spares for same is not applicable.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

Agreed it it is a OEM Standard design.

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Section / Part / Chapter / Volume

7

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

8

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

9

10

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

11

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

12

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

Clause No.

2.1

2.1

2.1

2.1

2.1

2.17

Page no.

Bid Specification Stipulation

Statement of Prebid Queries & Clarification

C. LOW TEMPERATURE SUPER HEATER (LTSH) Sheet 5 1)…………………. of 106 2) Bends - 20 Nos. (LOT) of each size, type, thickness, radius and material. 40 No’s supply tubes, bends/offset

Bidder has considered 20 Nos. of tube bend of each size, type, thickness, radius and material only. SJVN/DESEIN has to clarify the requirement of "40 No's supply tubes, bends/offset."

E. HIGH TEMPERATURE SUPERHEATER(HTSH) / FINAL Sheet 5 SUPERHEATER of 106 ……………. 3) Male & Female couplings spacers - 5 set

SJVN/DESEIN has to clarify the requirement of 5 set.

F. REHEATER ……………. Sheet 5 2) Male & Female couplings spacers - 5 set of 106

SJVN/DESEIN has to clarify the requirement of 5 set.

Sheet 9 of 106

1) Grinding elements a) Rollers/tyres/grinding balls.- 6 sets

Owner's Reply

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail.

The Provision as per Bidding specification shall prevail. This grinding element is called as 'Roller liners' as per Bidders nomenclature. Bidder has considered 1 Set equals to one mill requirement. Hence, Bidder will provide six (6) sets of roller liners. Agreed.

1) Grinding elements …………….. Sheet 9 b) Bull ring segments/ bowl / rings - 4 sets of 106

This grinding element is called as 'Table liners' as per Bidders nomenclature. Bidder has considered 1 Set equals to one mill requirement. Hence, Bidder will provide Four (4) sets of table liners. Agreed

Piping A. Power Cycle Piping Sheet 17 ……………….. of 106

There is repetition of Power Cycle piping in Mandatory Spare List. Bidder has considered Clause 2.17 for Power Cycle Piping

Power Cycle Piping 21

Sheet 32 of 106

19

Sheet 61 of 106

The Provision as per Bidding specification shall prevail.

Power Cycle Piping

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Section / Part / Chapter / Volume

13

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

14

15

16

17

18

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES Volume II General & Schedules CHAPTER 9 : MANDATORY SPARES

Clause No.

2.17

Page no.

Bid Specification Stipulation

Piping B. Low Pressure Piping Sheet 18 ……………….. of 106

Statement of Prebid Queries & Clarification There is repetition of Low Pressure piping in Mandatory Spare List. Bidder has considered Clause 2.17 for Low pressure Piping

The Provision as per Bidding specification shall prevail.

LP PIPING 7

Sheet 46 of 106 SCR System 2.28.1 Steam Soot Blower & Sonic Soot Blower

2.28

2.28

Owner's Reply

Sheet 19 Complete Assembly - 2 no. per Unit of 106

Either sonic blower or steam soot blowers as per OEM standard practice shall be provided.

LMB understand 1 no. per unit - Soot Blower requirement for One sootblower per Boiler. SJVN/DESEIN to clarify.

SCR System SJVNL to clarify the meaning of each unit. Is it one layer for each boiler unit 2.28.1 ……….. or one layer for each SCR unit? 2.28.2 Catalyst Sheet 19 Catalyst Module (to be supplied in a suitable packing so that it is of 106 not affected by outside environmental conditions during storage) Total no. equivalent to 1 Layer for each unit and to be supplied matching 75% guaranteed life of running catalyst. Complete compressor assembly - 1 No

2.28.9.1

Sheet 20 of 106

2.28.9.1

Sheet 20 of 106

1.00.16 C&I

Sheet 95 of 106

Complete compressor assembly - 1 No

Mandatory spares for each type of critical applications special control valves.

Bidder doesn’t recommend complete compressor assembly as the item is high durability item. Bidder may offer applicable spare for compressor as per OEM Bidder doesn’t recommend complete compressor assembly as the item is high durability item. Bidder may offer applicable spare for compressor as per OEM Please clarify us the control valves listed under critical applications special control valves.

The Provision as per Bidding specification shall prevail.

One layer for each one Boiler.

The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail. The Provision as per Bidding specification shall prevail.

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