1_power Piping_fabrication, Assembly, And Erection_v1.pdf

Fabrication, Assembly, Erection of Power Cycle Piping

Raghavendra Shenoy G Kannappan 10.09.2018 Knowledge City, Vadodara

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Power Piping

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CODES & STANDARDS ➢

Question Time …… ??????

➢

What is Code…… What is Standard…… ?

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What is a standard? ➢ A standard can be defined as a set of technical definitions and guidelines that function as instructions for designers, manufacturers, operators, or users of equipment.

➢ Standards, not having the force of law, are considered voluntary and serve as guidelines. ASME publishes standards and accredits users of standards to ensure that they are capable of manufacturing products that meet those standards. ➢ ASME, AWS, API, NACE, PFI are Standards RS \GK| Power Piping| Sept 09, 2018

What is a code?

➢ A standard is a code when it has been adopted by one or more governmental bodies and is enforceable by law, or when it has been incorporated into a business contract.

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ASME Codes and Standards ➢ ASME’s Codes and Standards organization develops and maintains standards and conformity assessment programs ❖ First standard issued in 1884 ❖ Approx. 600 consensus standards ❖ Over 100 ASME standards committees ❖ Over 3,600 volunteer committee members ❖ Standards address pressure technology, nuclear, safety, standardization, and performance test codes ❖ Conformity Assessment programs to accredit manufacturers of equipment

➢ Two different ASME standards ❖ ASME BPVC Codes RS \GK| Power Piping| Sept 09, 2018 ❖ ASME Other Standard

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ASME - Boiler and Pressure Vessel Code ➢ 12 volume or code sections: Section/Volumes

Description

I

Rules for Construction of Power Boilers

II

Materials Part A

Ferrous Material Specifications

Part B

Nonferrous Material Specifications

Part C

Specifications for Welding Rods, Electrodes, and Filler Metals

Part D

Properties

III

Rules for Construction of Nuclear Facility Components

IV

Rules for Construction of Heating Boilers

V

Nondestructive Examination

VI

Recommended Rules for the Care and Operation of Heating Boilers

VII

Recommended Guidelines for the Care of Power Boilers

VIII

Rules for Construction of Pressure Vessels

IX

Welding and Brazing Qualifications

X

Fiber-Reinforced Plastic Pressure Vessels

XI

Rules for In-service Inspection of Nuclear Power Plant Components

XII

Rules for Construction and Continued Service of Transport Tanks

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Other ASME Standards ➢ ASME B31.1 - Power Piping ➢ ASME B31.3 - Process Piping ➢ ASME B16.34 - Valves—Flanged, Threaded, and Welding End ➢ ASME B36.10M - Welded and Seamless Wrought Steel Pipe ➢ ASME PTC 6 - Steam Turbines ➢ ASME PTC 12.3 – Performance Test Code on Deaerators ➢ ASME PTC 8.2 - Centrifugal pumps . . . Etc. RS \GK| Power Piping| Sept 09, 2018

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ASME B31.1 - Power Piping ➢ Code Section includes ❖ References to acceptable material specifications and component standards, including dimensional requirements and pressure– temperature ratings ❖ Requirements for design of components and assemblies, including piping supports ❖ Requirements and data for evaluation and limitation of stresses, reactions, and movements associated with pressure, temperature changes, and other forces

❖ Guidance and limitations on the selection and application of materials, components, and joining methods ❖ Requirements for the fabrication, assembly, and erection of piping RS \GK| Power Piping| Sept 09, 2018

❖ Requirements for examination, inspection, and testing of piping

ASME B31.1 - Power Piping ➢ Contents of ASME B 31.1 Chapters

Description

I

Scope and Definitions

II

Design

III

Materials

IV

Dimensional Requirements

V

Fabrication, Assembly, and Erection

VI

Inspection, Examination, and Testing

VII

Operation and Maintenance

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Materials and Specifications ➢ Listed Materials ❖Materials for which listed in Mandatory Appendix A ❖A material conforming to a specification are not listed in Mandatory Appendix A is acceptable provided its use is not specifically prohibited by this Code and it satisfies • It is referenced in a standard listed in Table 126.1.

• It is referenced in other parts of this Code & only used within the scope of and in the product form permitted

Mandatory Appendix A RS \GK| Power Piping| Sept 09, 2018

Table 126.1

Materials and Specifications ➢ Unlisted Materials ❖Unlisted materials are certified by manufacturer to satisfy the requirements of the ASME B31, ASME BPVC, Section II, Part D, or to a published specification covering chemistry, physical and mechanical properties, method and process of manufacture, heat treatment, and quality control. ❖Unlisted materials shall be qualified for service within minimum and maximum temperatures based upon data associated with successful experience, tests, or analysis; or a combination thereof. ❖The designer shall document the owner’s acceptance for use of unlisted material. 12 ❖All other requirements of this Code are satisfied. RS \GK| Power Piping| Sept 09, 2018

Materials and Specifications • Unknown Materials. – Materials of unknown specification shall not be used for pressure containing piping components. • Materials Manufactured to Other Specification Editions – The materials are the same specification, grade, type, class, or alloy, and heat-treated condition, as applicable. – The material tensile and yield strengths shall be compared – If the material has a lower strength than required by Mandatory Appendix F, the effect of the reduction on the allowable stress and the design shall be reconciled. RS \GK| Power Piping| Sept 09, 2018

Mandatory Appendix F

Various materials used in Power sector

Various materials used in RS \GK| Power Piping| Sept 09, 2018 Power sector

Electrodes and Filler Metal • Conform to the requirements of the ASME BPVC Section II, Part C • WPS and WPQ shall be qualified as per ASME Section IX incase of filler metal not conforming to the above requirement • Unless otherwise specified by the designer, welding consumables used shall produce weld metal that complies with the following – Tensile strength of the weld metal shall equal or exceed the minimum tensile strength of the base metals. – Dissimilar base metals, tensile strength of the weld metal shall equal or exceed the minimum tensile strength of the weaker the two RS \GK| Powerof Piping| Sept 09, 2018

Electrodes and Filler Metal (Contd.) – Chemical analysis of the weld metal shall be similar to the chemical analysis of the base metal, including both major and essential minor alloying elements – Dissimilar base metals chemical analysis of the weld metal shall be similar to either base metal or intermediate, except for austenitic steels joined to ferritic steels. – Austenitic steels are joined to ferritic steels, the weld metal shall have an austenitic structure – For nonferrous metals, the weld metal shall be that recommended by the manufacturer.

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Electrodes and Filler Metal (Conti…) – Filler metals not meeting the above requirements may be accepted by agreement between the fabricator/erector & designer. – Examples, Unusual materials or combinations

To achieve desired mechanical properties

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127.2.2 Backing Rings • Ferrous Rings. – Ring which become permanent part of the weld shall be made from material compatible with the base material & sulfur content shall not exceed 0.05%. – Backing strips used at longitudinal welded joints shall be removed

• Nonferrous and Nonmetallic Rings – Backing rings may be used provided it is included in WPS. – Nonmetallic or nonfusing rings shall be removed.

127.2.3 Consumable Inserts – May be used provided, material compatible with the base material and WPS shall be qualified as per 18 para. 127.5 RS \GK| Power Piping| Sept 09, 2018

127.3 Preparation for Welding • Oxygen or arc cutting is acceptable – It is reasonably smooth and true – All slag is cleaned from the flame cut surfaces

• Discoloration that may remain on the flame cut surface. • Butt-welding end preparation as per ASME B16.25/ WPS • If piping component ends are bored, the finished wall thickness after welding shall not be less than the minimum design thickness. • If the piping component ends are upset, they may be bored to allow for a completely recessed backing ring, provided the remaining net thickness of the finished ends is not less than the minimum design thickness. RS \GK| Power Piping| Sept 09, 2018

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127.3 Preparation for Welding (Cont…) ➢ Cleaning ❖Surfaces for welding shall be clean; free from paint, oil, rust, scale or other material that is detrimental to welding. Problems in fit-up

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127.3 Preparation for Welding (Contd.) ➢ Alignment ❖Align ID of piping to be butt welded. ❖Tolerances on dia, wall thicknesses, and ovality ❖Internal misalignment more than 1⁄16 in. (2.0 mm), wall extending internally be internally trimmed • Thickens shall not be less than the minimum design thickness • Change in contour shall not exceed 30 deg

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127.3 Preparation for Welding (Cont…) Joint Angle

• Spacing. – The root opening of the joint shall be as given in the WPS

• Socket Weld Assembly.

Reinforcement Bead

Root Face Root Opening

Root Penetration

– Pipe or tube shall be inserted into the socket to the maximum depth and then withdrawn approx. 1⁄16 in. (2.0 mm) away from contact btw the end of the pipe and the shoulder of the socket – In sleeve-type joints without internal shoulder, there shall be a distance of approximately 1⁄16 in. (2.0 mm) between the butting 22 ends of the pipe or tube. RS \GK| Power Piping| Sept 09, 2018

127.4 Procedure

Remove tack welds made by an unqualified welder.

No welding, if it is impingement of rain, snow, sleet, or high wind

Tack welds by qualified WPS and welder.

Arc strikes outside the area, BM of should be avoided.

WPS qualification as Cracked tack welds -> removed. per ASME Section IX

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Stopping & starting ends -> prepared by grinding

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Surface of the weld • As-welded surfaces are permitted; however, shall be free from coarse ripples, grooves, overlaps, abrupt and valleys • The surface finished welds shall be suitable for interpretation of radiographic and other NDT • In cases of question regarding surface condition on the interpretation of a RT film, the film shall be compared to the actual weld surface for interpretation and determination of acceptability. • Undercuts shall not exceed 1⁄32 in. (1.0 mm) and shall not encroach on the minimum required section thickness. RS \GK| Power Piping| Sept 09, 2018

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Surface of the weld • If the surface of the weld requires grinding, care shall be taken to avoid minimum required thickness • Concavity on the root side of a single welded circumferential butt weld is permitted when the resulting thickness of the weld is at least equal to the thickness of the thinner member of the two sections being joined • The internal condition of the root surface of a girth weld, which has been examined by radiography, is acceptable if no RT requirement then same shall be visually examined RS \GK| Power Piping| Sept 09, 2018

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127.4.4 Fillet Welds • Weld metal shall be deposited in such a way as to secure adequate penetration into the base metal at the root • Fillet welds may vary from convex to concave. • Size of a fillet weld throat is determined as follows

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tn p nominal pipe wall thickness xmin. p 1.4tn or thickness of the hub, whichever is smaller

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127.4.5 Seal Welds. • Where seal welding of threaded joints is performed, threads shall be entirely covered by the seal weld. • Seal welding shall be done by qualified welders.

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127.4.8 Welded Branch Connections • Welded branch connections shall be made with full penetration welds, except as allowed • Typical details of branch connections with and without added reinforcement.

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127.4.8 Welded Branch Connections (Cont.) • Fig. below shows basic types of weld attachments used in the fabrication of branch connections.

Some Acceptable Types of Welded Branch Attachment Details31Showing Minimum RS \GK| Power Piping| Sept 09, 2018 Acceptable Welds

Welded Branch connections to the run pipe • Branch connections made by welding half couplings or adapters directly to the run pipe

Typical Full Penetration Weld Branch Connections for NPS 3 and Smaller Half Couplings or Adapters

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Specifically reinforced branch outlet fittings welded directly to the run pipe. • Branch connections using specifically reinforced branch outlet fittings welded directly to the run pipe.

(a) 90 deg Branch Fitting

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(c) Lateral Branch Fitting

(b) Elbow Branch Fitting

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Specifically reinforced branch outlet fittings welded directly to the run pipe (Contd.) • These branch connection fittings, half couplings, or adapters, which abut the outside surface of the run wall, or which are inserted through an opening cut in the run wall, shall have opening • Branch contour to provide a good fit and shall be attached by means of full penetration groove welds • The full penetration groove welds shall be finished with cover fillet welds • The cover fillet welds shall have a minimum throat dimension not less than that shown in above fig RS \GK| Power Piping| Sept 09, 2018

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Exception for above clause • Branch connections NPS 2 and smaller that do not require reinforcements may be constructed as shown in Fig

Typical Partial Penetration Weld Branch Connection for NPS 2 and Smaller Fittings

• Groove welds shall be cover fillet welds with a minimum throat dimension as shown in above fig. • This shall not be used at design temp. > 750°F (400°C) 37 or design pressures >1,025 psi (7 100 kPa). RS \GK| Power Piping| Sept 09, 2018

127.4.9 Attachment Welds.

• Structural attachments may be made by complete penetration, partial penetration, or fillet welds • Temporary attachments shall, after their removal, have the weld affected areas examined as per requirements

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127.4.11 Repair Welding • Defects in welds or base materials shall be removed by flame or arc gouging, grinding, chipping, or machining. • Preheating may be required for certain alloy materials – To prevent surface cracking adjacent to the flame or arc gouged surface.

• Post defect removal surface shall be contoured to eliminate any sharp notches or corners. • The contoured surface shall be reinspected by the same means originally used for locating the defect RS \GK| Power Piping| Sept 09, 2018

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Repair Welds • Repair welds only be qualified WPS/WPQ • As, that the cavity to be repair welded may differ in contour and dimension from a normal joint preparation and may present different restraint conditions.

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127.5 Qualification • Welder or welding operator shall be qualified as per ASME Section IX. • If material not appear in ASME Section IX but is assigned P-Numbers in Mandatory Appendix A may be welded for non-boiler external piping only without separate qualification.

127.5.2 Welding Responsibility • Each employer shall be responsible for the welding performance, welders or welding operators employed by his/her organization RS \GK| Power Piping| Sept 09, 2018

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127.5.3 Qualification Responsibility • Employer shall be responsible for qualifying any WPS that is intends to be used by organization. • WPS qualified by a technically competent group or agency may be used subject to approval of the owner. WPS meets procedure qualification requirements If fabricator accepts the WPS thus qualified

If user has qualified at least one welder using the WPS If user of the WPS assumes specific responsibility for the procedure qualification work done for him/her by signing the records All four of the above conditions shall be met before a WPS thus qualified 42 RS \GK| Power Piping| Sept 09, 2018

Qualification

Welders and Welding Operators ➢ Employer shall be responsible for qualifying all the welders and welding operators employed. ➢ To avoid duplication ❖WPQ made by previous employer (subject to the approval of the owner or his/her agent) on piping using the same or an equivalent procedure wherein the essential variables are within the limits established in ASME Section IX. ❖ Employer accepting such qualification tests by a previous employer with the original WPQ, showing the name of the employer who qualified with the dates of such qualification, and evidence that the welder or welding operator has maintained qualification requirement 43 RS \GK| Power Piping| Sept 09, 2018

Welders and Welding Operators ❖The evidence of process usage to maintain continuity may be obtained from employers other than the original qualifying employer. ❖The employer shall then prepare and sign the record required as required by ASME B 31.1 accepting responsibility for the ability of the welder or welding operator.

127.5.4 Standard Welding Procedure Specifications. • AWS Standard WPS & Mandatory Appendix E of ASME Section IX are permitted for within the limitations established by Article V of ASME Section IX. RS \GK| Power Piping| Sept 09, 2018

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127.6 Welding Records ➢ Employer shall maintain a record signed by him/her, and available to the purchaser or his/her agent and the inspector ❖WPS, PQR, date and results of procedure and performance qualification ➢ WPQ shall also show the welder or welding operator identification, ❖This may be accomplished by

or RS \GK| Power Piping| Sept 09, 2018

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129 BENDING AND FORMING • 129.1 Bending • Pipe may be bent by any hot or cold method and to any radius that will result in a bend surface free of cracks. • Bends shall meet the design requirements regard to minimum wall thickness • Where limits on flattening and buckling are not specified by design, manufacturing limits of PFI ES-24 shall be met or mutual agreement between purchaser &fabricator. • Beyond stated manufacturing limits shall not be allowed without the approval of the designer RS \GK| Power Piping| Sept 09, 2018

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129.2 Forming • Piping components may be formed by any suitable hot or cold working method, • Provided such processes result in formed surfaces that are uniform and free of cracks or other defects, as determined by method of inspection specified in the design.

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129.3 Heat Treatment of Bends and Formed Components • Hot bending or forming is performed at a temperature above Tcrit − 100°F (56°C). • Cold bending or forming is performed at a temperature below Tcrit − 100°F (56°C). – Where Tcrit is the lower critical temperature of the material.

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129.3 Heat Treatment of Bends and Formed Components (Contd.) • 129.3.2 A post-bending or post-forming heat treatment at the time and temperature cycles listed for PWHT in Table 132 is required on all CS (P-No. 1) materials with a nominal wall thickness in excess of 3⁄4 in. (19.0 mm) unless the bending or forming operations are performed and completed at temperatures of 1,650°F (900°C) or greater. • 129.3.3 For ferritic alloy steel (excluding P-No.1) materials with a nominal pipe size 4 in. and larger or with a nominal thickness of 1⁄2 in. (13.0 mm) or greater.

Hot

Full anneal, normalize and temper, or tempering heat treatment as specified by the designer

Cold

Heat treatment is required for the material in Table 132 49 RS \GK| Power Piping| Sept 09, 2018

129.3.4 austenitic materials heat treatment Postbending or post-forming • Heat treatment shall be made if they exceed both the design temperatures and forming strains shown in table

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Exceptions • Heat treatment shall not be required if the finishing forming temperature is equal to or greater than the minimum heat treatment temperature • Piping components being heat treated shall be held at the temperatures given in Table for 20 min/in. of thickness, or for 10 min, whichever is greater. • Incase if it is not identified in Table, then neither required nor prohibited. – If it is to be performed, the designer shall fully describe the procedure to be used RS \GK| Power Piping| Sept 09, 2018

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130 REQUIREMENTS FOR FABRICATING AND ATTACHING PIPE SUPPORTS

• Fabricated in accordance with the requirements of MSS SP-58 • WPS/PQR & WPQs -> ASME Section IX • If it is not manufactured as per MSS SP-58, shall be welded in accordance with para. 127 requirements. • Welds attaching hangers, supports, guides, & anchors to the piping system shall conform to the requirements of Chapters V and VI

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131 Welding Preheat • 131.1 Minimum Preheat Requirements

• 131.2 Different P-Number Materials

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131 Welding Preheat • 131.3 Preheat Temperature Verification – Preheat temperature shall be checked by use of • Temperature-indicating crayons • Thermocouple pyrometers • Other suitable methods

Ensure required preheat temperature is obtained prior to and uniformly maintained during the welding operation.

Thermocouple55pyrometers Temperature-indicating crayons RS \GK| Power Piping| Sept 09, 2018

131.4 Preheat Temperature

Minimum 50°F (10°C) preheat for all materials unless stated

P-No. 1

• 175°F (95°C) for material that has both a specified maximum carbon content in excess of 0.30% & a thickness at the joint in excess of 1 in. (25.0 mm).

P-Nos. 5A & 5B

• 400°F (200°C) for material that has either a specified minimum TS in excess of 60,000 psi (413.7 MPa), or has both specified minimum Cr content > 6.0% & thickness at the joint in excess of 1⁄2 in.(13.0mm) • 300°F (150°C) for all other materials having this P-Number

• 400°F (200°C) for all materials P-No. 15E RS \GK| Power Piping| Sept 09, 2018

131.6 Interruption of Welding ➢ After welding commences, the minimum preheat temperature shall be maintained until any required PWHT is performed on PNos. 3, 4, 5A, 5B, 6, and 15E, except when all of the following conditions are satisfied: ❖(A) A minimum of at least 3⁄8 in. (9.5 mm) thickness of weld is deposited or 25% of the welding groove is filled, whichever is less (the weldment shall be sufficiently supported to prevent overstressing the weld if the weldment is to be moved or otherwise loaded). ❖(B) For P-Nos. 3, 4, and 5A (with a chromium content of 3.0% maximum) materials, the weld is allowed to cool slowly to room temperature. RS \GK| Power Piping| Sept 09, 2018

131.6 Interruption of Welding ❖P-No. 5B (with a chromium content greater than 3.0%), P-No. 6, and P-No. 15E materials, the weld is subjected to an adequate intermediate heat treatment with a controlled rate of cooling. The preheat temperature may be reduced to 200°F (93°C) (minimum) for the purpose of root examination without performing an intermediate heat treatment. ❖After cooling and before welding is resumed, visual examination of the weld shall be performed to assure that no cracks have formed. ❖Required preheat shall be applied before welding is resumed. RS \GK| Power Piping| Sept 09, 2018

131.6 Interruption of Welding (Contd.)

• 131.6.2 Intermediate heat treatment for P-No. 5B or 15E materials may be omitted entirely when using lowhydrogen electrodes and filler metals classified by the filler metal specification with an optional supplemental diffusible-hydrogen designator of H4 or lower and suitably controlled by maintenance procedures to avoid contamination by hydrogen-producing sources. • The surface of the base metal prepared for welding shall be free of contaminants.

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132 Post Weld Heat Treatment • Shall satisfy WPS requirements • Welds of materials not included in ASME B 31.1shall be heat treated in accordance with qualified WPS. • Pressure part welds and attachment welds using ferritic filler metals that have a specified chromium content of more than 3% shall receive a PWHT. • PWHT time and temperature range used shall be that shown in Table 132 for a base metal.

Carbon Steel

P11 Material

P22 Material

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P91 Material

132.2 Mandatory PWHT Requirements The upper limit of the PWHT temperature range in Table 132 is a recommended value that may be exceeded provided the actual temperature does not exceed the lower critical temperature of either material meets procedure qualification requirements

If two different P-Numbers are joined by welding, the PWHT shall be that specified for the material requiring the higher PWHT temperature.

If a non-pressure part is welded to a pressure part and PWHT is required for either part, the maximum PWHT temperature shall not exceed the maximum temperature acceptable for the pressure retaining part

Caution is necessary to preclude metallurgical damage to some materials or welds not intended or qualified to withstand the PWHT temperatures required. RS \GK| Power Piping| Sept 09, 2018

132.3 Exemptions to Mandatory PWHT Requirements • PWHT is not required for the following conditions: Welds in nonferrous materials

Welds exempted in Table 132

Welds subject to above lower critical temp during fabrication provided the WPS has been qualified with PWHT at the temp. range to be reached during fabrication

• 132.4 Definition of Thickness Governing PWHT – Term nominal thickness as used in Table 132 and Notes is the lesser thickness of, • Thickness of the weld • Thicker of the materials being joined at the weld RS \GK| Power Piping| Sept 09, 2018

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Nominal Thickness calculation ➢ Thickness of the weld, a factor in determining the nominal thickness, is defined as follows: ❖ Groove welds – Thicker of the abutting ends after weld preparation, including I.D. machining ❖ Fillet welds - Throat thickness of the weld ❖ Partial penetration welds-Depth of the weld groove ❖ Material repair welds - Depth of the cavity to be repaired ❖ Branch welds - Weld thickness is the dimension existing in the plane intersecting the longitudinal axes and is calculated as indicated for each detail using 63 ❖Tc = the smaller RS of\GK|1⁄4 in.Sept or09,0.7tnb Power Piping| 2018

Wall thickness calculation

weld thickness = tnb + tc

weld thickness = tnh + tc

weld thickness = greater of tnr + tc or tnb + tc

64 weld thickness = tnh RS + \GK| tnrPower + tcPiping| Sept weld thickness = tnb + tc 09, 2018

Wall thickness calculation (Contd.)

(a) 90 deg Branch Fitting

(b) Elbow Branch Fitting

(c) Lateral Branch Fitting RS \GK| Power Piping| Sept 09, weld thickness = 2018 tnb + tc

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Wall thickness calculation (Contd.)

weld thickness = depth of groove weld + throat thickness of cover fillet

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132.5 PWHT Heating and Cooling Requirements • The rate of heating and cooling shall not exceed 600°F/hr (315°C/h) divided by one half the maximum thickness of material in inches at the weld, • But in no case shall the rate exceed 600°F/hr (315°C/h).

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132.6 Furnace Heating

➢ Heating an assembly in a furnace should be used when practical; ❖However, the size or shape of the unit or the adverse effect of a desired heat treatment on one or more components where dissimilar materials are involved, ❖May dictate alternative procedures such as heating a section before assembly, or by applying local heating. ❖An assembly may be PWHT in more than one heat in a furnace provided there is at least a 1 ft (300 mm) overlap of the heated sections and the portion of the assembly outside the furnace is shielded so that the temperature gradient is not harmful. ❖Direct impingement of flame on the assembly is 68 prohibited. RS \GK| Power Piping| Sept 09, 2018

132.7 Local Heating • Welds may be locally heat treated by circumferential band around the entire component with the weld located in the center. • Width of the band heated to the PWHT temp. for girth welds shall be at least three times the wall thickness at the weld of the thickest part being joined. • For nozzle and attachment welds, the width of the band heated to the PWHT temperature shall extend beyond the nozzle weld or attachment weld on each side at least two times the header thickness and shall extend completely around the 69header. RS \GK| Power Piping| Sept 09, 2018

132.7 Local Heating (Contd.) • Guidance for the placement of thermocouples is as per AWS D10.10. • Special consideration shall be given to the placement of thermocouples when heating welds adjacent to large heat sinks such as valves or flanges, or when joining parts of differing thicknesses, to ensure that no part of the materials subjected to the heat source exceeds the lower critical temperature of the material. • Particular care must be exercised when the applicable PWHT temperature is close to the material’s lower critical temperature, such as for creep strength enhanced ferritic steels.70 RS \GK| Power Piping| Sept 09, 2018

135.2 Alignment ➢ 135.2.1 Equipment Connections: When making connections to equipment, such as pumps or turbines or other piping components that are sensitive to externally induced loading, forcing the piping into alignment is prohibited ➢ 135.2.2 Cold Springs: Before assembling joints in piping to be cold sprung, an examination shall be made of guides, supports, and anchors for obstructions that might interfere with the desired movement or result in undesired movement. RS \GK| Power Piping| Sept 09, 2018

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135.3 Bolted Flanged Connections • 135.3.1 Fit Up. Contact surfaces bear uniformly on the gasket and then shall be made up with relatively uniform bolt stress. • 135.3.2 Gasket Compression. When bolting gasketed flange joints, the gasket shall be properly compressed • 135.3.3 Cast Iron to Steel Joints. Cast iron to steel flanged joints shall be assembled with care to prevent damage to the cast iron flange. • 135.3.4 Bolt Engagement. Shall have visible evidence of complete threading through the nut or threaded attachment. RS \GK| Power Piping| Sept 09, 2018

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135.5 Threaded Piping

• 135.5.1 Thread Compound: Lubricant used in threaded joints shall be suitable for the service conditions, and shall be compatible with material • 135.5.2 Joints for Seal Welding: Seal welded shall be made up without any thread compound.

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Carbon Steel

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P11 Material

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P22 Material

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P91 Material

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