Refinery And Seals

NRC-IRAQ Presented By: Rakesh Bhatiya + Jhony Mackenzie.

Sealing-Refinery applications.

Sealing Hydrocarbons

What does a oil refinery do ??? Crude oil is a cocktail of various different hydrocarbons. The typical compound of crude oils is: 83 - 87 wt % Carbon 11 - 15 wt % Hydrogen 0,1 - 7 wt % Sulphur 0,06 - 1,5 wt % Oxygen 0,1 - 0,5 wt % Nitrogen and other compounds Crude oil cannot be used directly in modern applications >>> it needs to be refined!

Sealing Hydrocarbons

What does a oil refinery do ??? Refineries transform crude oil into different end-products by applying physical, physical-chemical and chemical processes. The long molecule chains of crude oil are split (cracked) into shorter molecule chains or are re-arranged to form new products.

Principle of a refinery

Main units of a refinery Crude oil storage tanks Distillation Crackers De-sulphurisation Naphta Reformer LPG units Ready products

Principle of a refinery

Crude Oil tank farm Storgage of the incoming crude oil De-salination, pre-heating of crude oil Transport to first process stage: atmospheric + vacuum distillation

Principle of a refinery

Atmospheric + Vacuum distillation Seperating the crude oil in: light >>> LPG, gas middle >>> Oil, Naptha heavy >>> Bitumen, tar ...fractions by means of : high temperature and atmospheric pressure (atm. distillation) and moderate temperature and reduced pressure (vacuum distillation)

Principle of a refinery

Thermo - Catalytic - Hydro Crackers Separated fractions + heavy fractions from the distillation are split (cracked) into finer sub-fractions be means of: Thermal cracking

>>> high temperatures, no longer common

Catalytic cracking

>>> high temperatures + catalysator powder which has semi-liquid (fluid) characteristics (FCC = Fluid Catalytic Cracking) Good yield of high-octane fuel

Hydrocracking

>>> moderate temperatures + Hydrogen Most sophisticated crack-process

Principle of a refinery

De-sulphurisation Sulphur is an undesired compound in mineral-oil based hydrocarbons. It can be found in elementary form or as H2S. It must be removed from the hydrocarbons to receive pure endproducts. Modern environmental protection laws e.g. require lowsulphur fuels. H2S is extremely toxic and must be removed.

Principle of a refinery

Naptha Reformer The pre - stage of gasoline is called Naptha. Naptha or crude Benzine is not yet suitable to run modern gasoline engines as it contains a very low octane rate. Modern gasoline needs to have an octane rate of 91 -98. This is achieved in Naptha Reformer units. Katalytic reforming is commonly applied today. Platinium is used as catalyst - hence the idiom „Platforming“ is commonly used.

Principle of a refinery

Waste products Refineries produce considerable amounts of non-desired waste products, which need to be disposed, transformed processed. Waste gas: characteristic for all refineries are the burning flare stacks. Here, waste gas is being burnt. Coking:

The residue products (bottom product) is coked which means superheating under high pressure and no oxygen. Coke can be used as solid fuel material.

Calcination: Coke can be fully incinerated - creating calcinate. This material is used in the electronics industry to make electrodes etc.

Sealing Hydrocarbons

How to seal Hydrocarbons

echanical seals - principles Most common seal types in refineries: puscher – type seals with spring loaded unit and dynamic o-ring

Burgmann H75

Burgmann metal bellows seals for high temperature applications

MFL85N MFLWT80

but: a refinery also offers low-duty applications where standard cartridge seals such as Cartex or Mtex are perfectly suitable. > so: don‘t forget to look out for these

echanical seals - principles basic seal arrangements and layouts: single seal single seal with quench double seal – unpressurised buffer fluid double seal – pressurised barrier fluid

whatever seal arrangement – they all have one thing in commo > all seals are desigend as ready-to-install cartridge seals !

ic seal arrangements and layouts: Single seal

flush connection + multipoint injection

balanced seal design

dynamic o-ring low emission principle: „V“ means support ring under the carbon face

ic seal arrangements and layouts: Single seal with quench

same design features as single seal + additionally: quench connection port

floating throttle bushing

ic seal arrangements and layouts: Single seal with quench

pose of a quench: ute and remove leakage event deposits on atmospheric side of the seal ep away air (oxygen) from leaked media in order to prevent oxid .g.: hot oil will create coke sediments when in contact with air) ep the seal cool or hot Typical quench media in refineries: Purpose Quench media Prevent coking of hot oil Cooling the seal Heating the seal Removing deposits, cleaning the seal

Nitrogen or steam Cool liquid, diesel, oil Hot steam Clean liquid which will dilute the deposits

ic seal arrangements and layouts: Double Seal flush connection + buffer fluid IN buffer fluid OUT multipoint injection

product side (inboard) sealatmospheric side (outboard) seal

ic seal arrangements and layouts:

Double seal – unpressurised buffer fluid higher product pressure (p1)

lower buffer pressure (p3)

atmospheric pressure (p2) p3 = p2

leakage of media into the buffer fluid leakage of buffer fluid into the atmosphere Consequences: - media will accumulate in the buffer fluid -TS vessel level will rise - Traces of media will get contact with the atmosphere

ic seal arrangements and layouts: Double seal – pressurised barrier fluid product pressure (p1)

higher barrier pressure (p3) p1 < p3 >p2

leakage of barrier fluid into media leakage of barrier fluid into the atmosphere Consequences: - barrier fluid will escape into the media -TS vessel level will drop - Visible leakage on atmospheric side will be only clean barrier fluid

atmospheric pressure (p2) p3 = p2

cret: the most common API Plans in refineries

API Plan 11

Description: Flush Layout: Pipe from pump discharge through 3 mm orifice to stuffing box chamber Purpose: Cooling, diluting gas ring, preventing vaporisation Common applications: Flashing hydrocarbon Media which tends

cret: the most common API Plans in refineries

API Plan 02

Description:Dead End Layout: Connection port, plugged Purpose: For customer‘s determination Common applications: where plan 11 will cause problems: high temperature and high content of solids

cret: the most common API Plans in refineries

API Plan 62

Description: Quench

Layout: Introduction of clean fluid betwe atmospheric end of seal and throttle bushing Purpose: Diluting and removing leakage deposits Cooling & heating of seal preventing coking of hot oil Common applications: Hot oil Bitumen / tar media with solids

cret: the most common API Plans in refineries

API Plan 52

Description: Pressureless buffer fluid

Layout: Circulation of buffer fluid throu a pressureless TS vessel

Purpose: Lubricating the 2nd backup sea Diluting leakage Monitoring seal behaviour (leakage, failure) Improving lubrication of seal Common applications: Media with poor lubricity Harmful media

cret: the most common API Plans in refineries API Plan 53A

Description: pressurised barrier fluid circulation through TS vessel Layout: TS vessel pressurised with Nitrogen Purpose: Media may not leak towards the atmosphere. Media must be kept inside pump Common applications: Media with high content of solids Dangerous Media Media with very poor lubricity

cret: the most common API Plans in refineries API Plan 53B

Description: pressurised barrier fluid circulation through TS vessel Layout: TS vessel pressurised with bladder accumulator

Purpose: Media may not leak towards the atmosphere. Media must be kept inside pump Common applications: Media with high content of solids Dangerous Media Media with very poor lubricity

cret: the most common API Plans in refineries

API Plan 53C

Description: pressurised barrier fluid circulation through pressure transmitter (DRU) Layout: seal pressurised by DRU pressure transmitter Purpose: Media may not leak towards the atmosphere. Pressure difference between product and atm. side very high Common applications: Media with high content of solids Dangerous Media Very high pressure

cret: the most common API Plans in refineries API Plan 54

Description: pressurised barrier fluid circulation through external supply system Layout: Seal connected with external supply system (SPA) Purpose: Media may not leak towards the atmosphere. Media must be kept inside pump Common applications: Media with high content of solids Dangerous Media Media with very poor lubricity

aterials for refinery seals Seal Faces  Clean medium: Carbon, antimony impregnated <> Silicon Carbide (Buko 03 <> Buka 22)  Medium containing solids: Silicon Carbide <> Silicon Carbide (Buka 22 <> Buka 22)

Secondary Sealing Elements  Chemical resistance > usually Viton is suitable for most HC. However, never use EPDM (not resistent to mineral oils)!  Temperature range. Most Elastomers are limited at 180°C - 200°C.

Construction Materials

eal selection in refineries

1) knowing the media:       

name, vapour pressure, density (spec. gravity), viscosity, hazards, solids, corrosive?

eal selection in refineries

2) Temperature range

< - 40°C:

- 40°C to + 220°C :

Metal bellows seal with Graphite secondary seals (MFLCT80) Pusher-type o-ring seal (e.g. H75)

+ 220°C to + 300°C: Standard metal bellows seals (e.g. MFL85, Mtex)

> +300°C :

Metal bellows seal with Graphite secondary seals (MFLWT80)

eal selection in refineries

3) Pressure  suction, discharge, stuffing box  the margin between stuffing box pressure and vapour pressure of media shall be approx. 2 bar H75 type seals have a pressure limit of approx. 40 bar MFL type seals are limited to 25 bar.

eal selection in refineries

• density – spec. gravity – spec. weight > lubricity is the media in liquid phase at all times – or is there a risk of dry running? If vapour pressure is not indicated, this will give a rough estimation, which seal Density kg/m³ Seal Type arrangement is suitable: >750

Single

750– 650

Single, withmultipointinjection(Plan11)

650– 550

Doubleseal, pressureless buffer fluid(Plan52)

<550

Doubleseal, pressurisedbarrier System(Plan53)

eal selection in refineries

5) sliding velocity most process pumps in refineries have a speed of approx. 2950 rpm. More important than the rpm is the resulting sliding velocity of the calculating the sliding velocity in m/s: mechanical seal. mean diameter of the seal face X rpm X 3,14 60.000 > In most cases, seal max. velocity is 25 m/s

ISO/NP21049 (API 682, 2nd Edition)

Scope ISO / NP 21049 - General

ISO / NP 21049 is guideline a the forminimum requirement for Shaft Sealing Systems for Centrifugal and Rotary Pumps usedin petroleum natural , gas and chemical industry

Scope ISO / NP 21049 - General

ISO / NP 21049 covers shaft seals for

from to

diameters

20 mm (0,75 in) 110 mm (4,3 in)

Scope ISO / NP 21049 – Seal categories

Category 1 For nonISO 13709SealChambers Temperatures from -40 °C (-40 °F) to 260 °C (500 °F) AbsolutePressures up to 22 bar (315 psi)

Scope ISO / NP 21049 – Seal categories

Category 2 For ISO 13709SealChambers (Table 1 only) Temperatures from -40 °C (-40 °F) 400 to °C (750 °F) AbsolutePressuresup to 42 bar (615 psi)

Scope ISO / NP 21049 – Seal categories

Category 3 Must meet specification full (incl. documentation) For ISO 13709SealChambers (Table 1 only) Temperatures from -40 °C (-40 °F) 400 to°C (750 °F) AbsolutePressuresup to 42 bar (615 psi)

Scope ISO / NP 21049 – Seal types

Type A • Balanced internally - - mounted • •cartridge • pusher m • ultiple springs element rotating • flexible secondary sealing by elastomer o-rings •

Scope ISO / NP 21049 – Seal types

Type B • Balanced • internallymounted •cartridge ) pusher metal ( bellows • nonelement rotating • flexible secondary sealing by elastomer o-rings •

Scope ISO / NP 21049 – Seal types

Type C • Balanced internally - mounted • •cartridge ) pusher metal ( bellows • nonelement stationary • flexible secondary sealingflexible by graphite •

Scope ISO / NP 21049 – Seal arrangements ISO / NP 21049 covers 3 Arrangements: Arrangement 1: one seal per cartridge assembly Arrangement 2: two sealsper cartridge assembly with a containment seal chamber at pressure less than the seal chamber pressure

Arrangement 3: two sealsper cartridge assembly with externally supplied barrier fluid

Scope ISO / NP 21049 – Sealing methods

ISO / NP 21049 covers 3 Designs: •

Contacting Wet Seals (CW)

•

Non-contacting Seals (wet or dry, NC)

•

Containment Seals (contacting or non-contacting, CS)

Scope ISO / NP 21049 – Sealing methods

ISO / NP 21049 covers 3 orientations for Arrangements 2 & 3: •

Face-to-Back

•

Back-to-Back

(arr.2 default selection & arr. 3 wet seals)

(arr. 3 default for gas seals; option for wet seals)

•

Face-to-Face (arr.3 optional selection for wet or gas seals)

ISO / NP 21049 – design requirements

Materials Category 1 Mech. Seal Face Mating Ring Hard / Hard Secondary elements

Springs Bellows Sleeves Housing

Category 2 Category 3

Carbon Carbon SSSiC RBSiC (Buka 22) (Buka 20) SSSiC/ RBSiC/ SSSiC RB SiC Fluoroelastomer Perfluoroelastomer (altern.: TFE, Nitrile ..) Flexible graphite Alloy C-276 or Alloy C-4 (single: SS 316 or 1.4571) Alloy C.276 (Type B) Alloy 718 (Type C) SS 316 or 1.4571 SS 316 or 1.4571

Carbon RBSiC (Buka 20) RBSiC/ RBSiC

BURGMANN Mechanical Seal Type

H75

Type A

Arrangement 1 API 682 Code: C2A1A1161 Pressure:

0... 42bara / 580psia Temperature : -40 °C .. +180°C -40° F.. +350°F Speed: 20 m / 65,6ft. persecond

BURGMANN Mechanical Seal Type

H75K & H75F

Type A

Arrangement 2 or 3 API 682 Code: C2A2A1152 or C2A3A1153 Pressure

0... 42 bara / 580psia Temperature : -40 °C .. +180°C/ -40° F.. +350°F Speed: 20 m / 65,6ft . per second

BURGMANN Mechanical Seal Type

MFL85N

Type B

Arrangement 1 API 682 Code: C2A1B1161

Pressure:

0... 25bara/ 365psia

Temperature : -40 °C / +180°C -40°F /+350°F Speed :

20 m/ 65,6 .ftper sec.

BURGMANN Mechanical Seal Type

MFL85N + MFL85F

Type B

Arrangement 2 and 3 API 682 Code: C2A2B1152 or C2A3B1153 Pressure:

Temperature : Speed:

0... 25 bara 0 ..365psia -40 °C .. +180°C -40°F..+ 350°F 20m/s 65,6 ft . per sec

BURGMANN Mechanical Seal Type

MFL65

Type C

Arrangement 1 API 682 Code: C2A1C0262 Pressure: Temperature : Speed:

0...25bara/ 362,5psia -20°C / +400°C -4°F / 752°F 50 m /164.ftper sec.

MFL

MFL

MFL Design of a MFL-seal While common pusher-seals are built-up by a large number of single parts, the MFL-Seal contains only very few components: Bellows unit

stationary seat

sec. seal

Bellows unit Stationary seat Secondary seals

set screw

secondary seal

MFL Design of a Bellows Unit

bellows carrier

metal bellows

seal face housing

seal face

MFL Advantages • No blocking of the shaft seal

The spring-loaded mechanical seal is blocked by deposits at the dynamic O-ring and therefore unable to self-align.

• No wear of the shaft • Self-cleaning bellows • Balanced arrangement • High-temperature applications • Compact design

The MFL-Seal is equipped with a static shaft seal. Therefore no blocking of the rotating seal due to deposits will occur.

MFL Bellows - Types

• Membrane bellows (lamella bellows) Unlike rolled metal bellows, membrane bellows consist of multiple membrane leaves which are welded at the inner and outer diametric edges. Cross-section of a Burgmann membrane bellows

MFL Balanced at Internal & External Pressurization AH

A

Tandem or single operation externally pressurized p3 < p1

d Hi

A

Dual Operation internally pressurized p3 > p1

d Ha

AH

  

The MFL tandem dual seal is either used with pressurized barrier fluid or with unpressurized buffer fluid The seal remains closed even if barrier pressure breaks down Advantage: max. operational reliability is provided in case barrier pressure break down is not discovered at once

MFL Seal Classification MFL Seals Rotating bellows unit standard

engineered

Stationary bellows unit standard

MFL85N

MFLS (low temperature) MFLWT80S

MFLWT80 (MFLW80) MFLCT80 (high temperature) (low temperature)

MTEX

engineered

MFLW81S (shaft sealing)

MFL65

MFLS (Aerospace)

MFL Seal Types MFL85N

• Basic model of the MFL series • Fitting dimensions acc. to DIN 24960 • Balanced even on a plain shaft • External- and internal pressurization (positively retained stationary seat required at internal pressurization) • Amplitude limitation in order to avoid cracking of bellows in case of undue radial excentricity (e.g. flashing hydrocarbons) 1.1 1.2 1.3 2. 3.

Seal face with bellows unit O - ring Set screw Stationary seat O - ring

MFL Seal Types MFL85F

• Dimensions, positions, designation, and properties identical to MFL85N - however additionally equipped with pumping screw.

1.1 1.2 1.3 1.4 2. 3.

Seal face with bellows unit O - ring Set screw Pumping screw Stationary seat O - ring

MFL Seal Types MFLW(T)80

Operating Limits: d 1=

16 ... 100 mm (0,6 ... 3,9")

p 1=

25 bar (360 psi)

vg = 15 m/s (50ft/s)

t = - 20°C ... + 400°C (- 4°F ... + 752°F)

MFL Seal Types MFL65 - API 682

Operating Limits: d1 = 16 ... 100 mm (0,6 ... 3,9 ") p1 = t

=

vg =

25 bar (360 psi) - 20°C ... + 400°C (- 4°F ... +752°F) 50 m/s (165 ft/s)

MFL85 - Stationary Seats

MFL85N/dw-00 MFL85N/dw-G16 MFL85N4/dw-00 MFL85N/dw-G82 MFL85N/dw-G320 MFL85N/dw-G60 MFL85N/dw-GX

MTEX - Cartridge Concept

MTEX

MTEX - Cartridge Concept x

MTEX - SO

x

    

Single seal Balanced Independent of direction of rotation Cover without supply connections ("dead-end") Sturdy design

Burgmann Total Seal Care Program – Middle East References 2. ARAMCO - Riyadh Refinery, KSA 3. ISO Octane Refinery – Dubai 4. KNPC – MAB Refinery, Kuwait 5. ADCO – Abu Dhabi 6. Total E&P Qatar 7. Maersk Oil Qatar 8. Borouge- Abudhabi 9. Sohar Refinery.

Note : Scope of the contract is suited to the needs / wants of the Customer.