DGS-MU-017 - Rev 2

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Abu Dhabi Oil Refining Company

SHAFT SEALING SYSTEMS FOR CENTRIFUGAL & ROTARY PUMPS(AMENDMENTS / SUPPLEMENT TO API 682)

DGS-MU-017Rev- 2

Dec 2013

Takreer DGS-MU-017 Rev-2 Dec 2013 Initials Page 1 of 41

SHAFT SEALING SYSTEMS FORCENTRIFUGAL & ROTARY PUMPS

(AMENDMENTS / SUPPLEMENT TO API 682)

Amendment History

02 Dec 2013 DGS-MU-017 Rev-2 Clause No. 8.5.4.3

Clause No. 1.0 Scope

Clause No. 3.0

DDC VP(E&TSD) Dec 2013

01 June 2009 AMD-MU-017-001-BECHTEL

Section # 1.0, 2.0 & 9.0

Clause # 1.4, 4.2.3, 6.1.1.6,4.2.3, 8.1.3, 8.1.8, 8.2.1,8.4.1, 8.5.3.1, 8.5.4.1, 8.5.4.2,8.5.4.4.11, 8.5.4.5g, 8.5.4.7,8.6.2.2, 8.6.5.2e, 8.6.5.3,8.6.5.4, 8.6.6.1 & 8.6.6.2,

Appendix 1

Annex A, B & G

SMK /HD

QAM / MAY June 2009

No Date Amendment Description Proposed Approved Incorporated

DGS History

2 Dec 2013 DGS-MU-017 Rev-2 DGS Discipline Committee DDC VP(E&TSD)

1 June 2009 DGS-MU-017 Rev-1 AMD-MU-017-001-BECHTEL SMK / HD QAM / MAY

0 Feb 2008 DGS-MU-017 Rev-0 Previous Project SMK / HD ETSDM / EPDM

DGS-MU-017 Rev-2

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No Date Description Source Reviewed Approved

TABLE OF CONTENTS

PARTI SCOPE ............................................................................................................................... 41.0 INTRODUCTION .......................................................................................................... 42.0 ALTERNATIVE DESIGNS ............................................................................................ 4

PARTII AMENDMENTS/SUPPLEMENTSTOAPI682 ................................................................. 41.0 SCOPE......................................................................................................................... 42.0 NORMATIVE REFERENCES ....................................................................................... 5

3.0

TERMS AND DEFINITIONS ......................................................................................... 64.0 SEALING SYSTEMS .................................................................................................... 6

4.1 SEALCATEGORIES,TYPESANDARRANGEMENTS .............................................. 64.2 OBJECTIVES ............................................................................................................ 7

6.0 DESIGN REQUIREMENTS .......................................................................................... 86.1 COMMON DESIGN REQUIREMENTS (ALL CATEGORIES) .................................... 8

7.0 SPECIFIC SEAL CONFIGURATIONS ........................................................................ 107.2 ARRANGEMENT 2 SEALS ..................................................................................... 10

8.0 ACCESSORIES ......................................................................................................... 118.1 AUXILIARY PIPING SYSTEMS ............................................................................... 118.2 MECHANICAL SEAL FLUSH/COOLING SYSTEMS (GROUP I) ............................. 118.3 QUENCH SYSTEM (GROUP II) .............................................................................. 12

8.4 COOLING WATER SYSTEMS (GROUP III) ............................................................ 128.5 ACCESSORIES AND AUXILIARY SYSTEM COMPONENTS ................................. 128.6 BARRIER/BUFFER FLUID AND SEAL FLUSH POSITIVE CIRCULATING DEVICES

................................................................................................................................ 179.0 INSTRUMENTATION.................................................................................................. 1810.0 INSPECTION, TESTING AND PREPARATION FOR SHIPMENT ............................... 18

10.1 GENERAL ............................................................................................................... 1810.2 INSPECTION .......................................................................................................... 1810.3 TESTING ................................................................................................................. 18

11.0 DATA TRANSFER ...................................................................................................... 1911.1 GENERAL ............................................................................................................... 19

APPENDIX 1 SEAL SELECTION PHILOSOPHY ......................................................................... 20

ANNEX A

RECOMMENDED SEAL SELECTION PROCEDURE ............................................. 24

ANNEX G.32 API 682 PLAN 53 MODIFIED, TYPE 1 WITH AIR FIN TUBE (NATURALCONVECTION) OR WATER COOLING .................................................................. 28

ANNEX G.33 API 682 PLAN 53 MODIFIED, TYPE 1 WITH AIR FIN TUBE (NATURALCIRCULATION) OR WATER COOLING FOR BETWEEN BEARINGS PUMP ......... 29

ANNEX G.34 API 682 PLAN 53 MODIFIED, TYPE 2 WITH AIR FIN TUBE (NATURALCIRCULATION) OR WATER COOLING .................................................................. 30

ANNEX G.35 API 682 PLAN 54 MODIFIED .................................................................................. 31ANNEX G.36 API 682 PLAN 52 .................................................................................................... 32ANNEX G.37 MAKE-UP SYSTEM FOR API PLAN 53 MODIFIED AND/OR 52 SEAL SYSTEMS . 33ADDENDUM SHEET ...................................................................................................................... 34

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LIST OF AUTHORIZED SIGNATURES INITIALS

DGS Discipline Committee Member, ADRD Ramesh Rao Kaliyamurthy

DGS Discipline Committee Member, RR Soman Mukherjee

DGS Discipline Committee Member, E&TSD Megharaj Laxman Mane

DGS Discipline Committee Leader, E&TSD Abdulla Musaed Al Harthi

Standards & Procedures S/H, E&TSD Abdulla Musaed Al Harthi

Vice President, E&TSD Salem Obeid Al Dhaheri

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PARTI SCOPE

1.0 INTRODUCTION

This specification contains the requirements and recommendations for the selection ofshaft seals and their related environmental control systems for centrifugal and rotarypumps.

This specification is based on and shall be used in conjunction with API 682, 3rdeditionSeptember 2004. Part II of this specification amends, supplements and deletes variousclauses of API 682. Clauses of API 682 that are not modified shall remain completely

valid as written.

This specification supplements the requirements specified on the individual EquipmentData Sheets. Where conflicts exist, the Data Sheets shall govern.

This Specification is intended for use in oil refineries, gas plants, chemical plants and allutility facilities.

Where national and/or local regulations are more stringent than those specified in thisSpecification, the CONTRACTOR shall determine which of the requirements are themore stringent and which combination of requirements will be required with respect tosafety and environmental issues. In all cases the CONTRACTOR shall inform the COM-PANY of any deviation from the requirements of this Specification that are necessary to

comply with national and/or local regulations.

2.0 ALTERNATIVE DESIGNS

The acceptance of alternative designs shall be subject to the prior approval of COMPA-NY.

Seal MANUFACTURERS shall review all seal applications as submitted by pump VEN-DORS. The seal MANUFACTURER shall notify the pump VENDOR and COMPANY if adeviation from the requirements in the data sheets or this specification would result inequal or improved sealing based on their seal experience on similar applications

PARTII AMENDMENTS/SUPPLEMENTSTOAPI682

1.0 SCOPE

[Add] This standard applies to the shaft sealing equipment commonly supplied for thespecified service(s) which will meet the objective of at least five years of uninterruptedservice while complying with the specified emission regulations.

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This specification covers the minimum requirements for shaft seals and their sealing sys-tems for centrifugal and rotary pumps. The applications addressed in this specification

cover sealing duties for pumps with a working temperature range of -40 to +400 C and amaximum allowable working pressure up to 42 bar (abs). It covers seals for pump shaftdiameters from 20 mm to 110 mm. Seal applications outside these boundaries are sub-ject to the same design and configuration, shall be termed as Engineered Seals andshall require COMPANY's approval. The seal Vendor shall supply references of seals insimilar services.

2.0 NORMATIVE REFERENCES

[Add to end of references:]

It shall be the VENDORS responsibility to be fully knowledgeable of the requirements ofthe referenced Codes and Standards.

The following reference documents form an integral part of this specification. When anedition date is not indicated for a document, the latest edition in force at the time ofCONTRACTORS/VENDORS proposal submittal shall apply.

American Standards

API 682 Shaft Sealing Systems for Centrifugal and Rotary Pumps

NACE MR0103 Materials Resistant to Sulfide Stress Cracking in Corrosive Petro-

leum Refining Environments

NACE TM0103 Laboratory Test Procedures for Evaluation of SOHIC Resistanceof Plate Steels Used in Wet H2S Service

NACE TM0284 Evaluation of Pipeline and Pressure Vessel Steels for Resistanceto Hydrogen-induced Cracking

Briti sh Standards

EN 10204 Metallic Materials Types of Inspection Documents

Design General Specifications

DGS-IU-007 Instruments Furnished with Package Units

DGS-MG-001 Centrifugal Pumps (Amendments / Supplement to API 610)

DGS-MG-003 Centrifugal Pumps for General Services

DGS-MG-004 Positive Displacement Pumps Rotary (Amendments / Supple-ment to API 676)

DGS-MU-006 Rotating Equipment Minimum General Requirements

DGS-MU-007 Rotating Equipment System Integration

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3.0 TERMS AND DEFINITIONS3.79 [New] HAZARDOUS AND TOXIC SERVICE This specification defines hazardous and

toxic service for mechanical seals and their related seal systems as a service used inone or more of the following categories:

Category 1:

Liquids containing hydrogen sulphide in concentrations above 500 ppm.

Liquids containing lethal substances as indicated in the data sheet. Examples of le-thal substances include but are not limited to: HF acid, phenol, concentrated sul-phuric and nitric acid.

Category 2:

Liquids containing toxic substances as indicated in the data sheet. Examples of tox-ic substances include, but are not limited to, benzene, toluene, MEK, and ethyleneoxide.

Hydrocarbon liquids operating at design or emergency off design temperaturesabove their auto-ignition temperature.

Category 3:

Hydrocarbon liquids with a seal chamber vapour pressure higher than 5 bar (abs).

Hydrocarbon services of butane (C4) or lighter.

3.82 Plan 54 (Plant wide) - Is a plan 54 where the external seal flush is supplied from plant-widesystem engineered and supplied by the buyer.

3.83 Plan 54 (Stand-alone) - Is a plan 54 where the external seal flush is supplied from a Stand-alone seal support console engineered and supplied by the seal supplier. There will beone such console per pump. The external flush fluid shall have dual pumps, one runningand one stand by.

4.0 SEALING SYSTEMS

4.1 SEAL CATEGORIES,TYPES ANDARRANGEMENTS

[Add] Refer to Appendix 1 Seal Selection Philosophy for general guidelines on seal se-lection.

4.1.1 [Add] The inner seals of arrangement 2 mechanical seals shall be designed with a posi-tive means of retaining the sealing components. They shall be designed with sufficientclosing force to prevent the faces from opening upon pressurization of the buffer fluid tothe maximum specified back pressure from the connecting flare or vent system or 4.5bar (abs), whichever is higher. In the design for this condition the prevailing normal suc-tion pressure of the pump may be taken into account.

4.1.5 [Add] A back-to-back (face-to-face) seal arrangement shall be considered if the requireddifferential pressure across the inner seal (due to a specified high barrier pressure ver-

sus a low seal chamber pressure) is considered too high to ensure a reliable operationwith a tandem arrangement.

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4.2 OBJECTIVES4.2.1 [New] SEAL SELECTION

Mechanical seal application details shall be as specified in the data sheets of the pumpand on the API 682 data sheet.

Seals shall be selected to achieve a minimum of five years of uninterrupted operation.

The following applications require the specific pre-approval of COMPANY:

Plan 54 for dual seals in Category 1 liquid services, see paragraph 3.79

Dual unpressurized tandem seals with Plan 52 in Category 2 services, see para-graph 3.79

Single seals with auxiliary seals, other than dry gas seal types.

Seals and seal arrangements and seal piping shall be selected in accordance with An-nex A. Part 1 of Annex A presents the requirements of this sub-section in graphical form.Part 2 of Annex A presents the requirements for dual seal arrangements and their relatedseal plans and piping.

Dual seals shall be applied in the following services:

1. Hazardous services (see paragraph 3.79)

2. Services in which the required five year operation cannot be ensured with a singleseal application due to the physical or chemical properties of the liquid to be

sealed.3. Services in which it is not permitted for the pumped liquid to enter the flare or at-

mosphere. In this case, dual pressurized seals shall be applied.

Dual pressurized seals shall be applied for the following services as a minimum:

a. If the available seal liquids are not compatible with the required seal conditions toobtain the required five years life.

b. Hazardous and toxic service (as defined in Specification DGS-MU-006 and para-graph 3.79 above).

c. Services containing H2S which upon seal failure will result in an H2S leakage rateto atmosphere exceeding 1g/s.

d. Fluids with specific gravity less than 0.7.

e. Operating temperatures higher than 200C.

If dry running dual seals are not used, Plans 52, 53 A/B or 54 shall be used. Nitrogencylinders and/or sealant refill equipment kit shall be in CONTRACTORS scope.

If the presence of abrasive particles at the seals can not be avoided, the pump shall bean API 610 slurry type pump with expellers and both seal faces shall be of hard material.

4.2.2 [New] Proposals for dry gas seal arrangements in pumps versus standard dual seal ap-plications are subject to the pre-approval of COMPANY and shall be limited to the follow-ing:

1. A single liquid seal and a dry gas back-up seal arrangement may be considered on-ly for liquids not classified as Category 3 as defined in paragraph 3.79;

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2. Dual pressurized dry gas seal arrangements with a pressurized nitrogen barriermay only be considered for liquids that are not classified as hazardous (see para-graph 3.79) and have a maximum vapour pressure at pumping temperature of 1.05bar (abs). Attention shall be paid by the CONTRACTOR in this application to en-sure a reliable nitrogen supply system.

6.0 DESIGN REQUIREMENTS

6.1 COMMON DESIGN REQUIREMENTS (ALL CATEGORIES)

6.1.1.1 [Add] Bolting or set screws used to assemble seal cartridges shall have sufficientstrength to withstand the force needed to remove the cartridge from the pump, taking intoaccount the high friction which may be present due to deposits between the shaft and theshaft sleeve.

6.1.1.6 [Replace the last sentence by] The static sealing pressure rating (SSPR) of mechanicalseals shall be greater than or equal to the maximum static sealing pressure (MSSP),which shall be calculated as indicated below.

For Arrangement 1 seals, the MSSP of each seal shall be equal to the maximum staticseal chamber pressure that can occur in the pump. Unless otherwise specified, this shallbe the shut-off pressure of the pump at maximum suction pressure.

For Arrangement 2 seals, the MSSP of both the inner and outer seal shall be equal to themaximum static seal chamber pressure that can occur in the pump. Unless otherwisespecified, this shall be the shut-off pressure of the pump at maximum suction pressure.

For Arrangement 3 seals, the MSSP of the outer seal shall be equal to the maximumstatic seal chamber pressure that can occur in the pump. Unless otherwise specified, thisshall be the greater of 1) shut-off pressure of the pump at maximum suction pressure or2) the maximum barrier fluid pressure. The MSSP of the inner seal shall be the greater of1) differential between the maximum barrier fluid pressure and the minimum seal cham-ber pressure or 2) the maximum differential between maximum seal barrier fluid pressureand atmospheric pressure.

6.1.1.11 [Add] Unless otherwise specified by COMPANY, single mechanical seals in vacuum ser-vice shall be of the metal bellows type and shall be suitable for the lowest specified staticor dynamic seal chamber pressure.

6.1.2 Seal Chamber and Gland Plate

6.1.2.14 [Replace the 2nd sentence in 2nd paragraph by] Where seal chamber conditions do notmeet the specified margins or where sealing pressures are higher than 5 Bars, the sealMANUFACTURER shall:

c) [Replace] furnish the seal gland plate or the seal chamber with a second flush connec-tion and a pressure gauge (minimum 4 dial size) to permit measurement of seal cham-ber pressure directly

[Delete] The NOTE: 2nd paragraph, Lowering the flushover vapour pressure.

[Add] The dynamic seal chamber pressure for single seals or for the inner seal of an un-pressurized dual tandem seal arrangement shall exceed the maximum pumped liquidvapour pressure at maximum seal chamber liquid temperature by at least 3.5 bar or10%, whichever is higher.

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In addition, for pumped liquids with a seal chamber vapour pressure above 10 bar (abs),the seal chamber pressure and temperature of the liquid shall be such that a tempera-

ture rise of 10C will not result in vapour formation.

The margins required in the above paragraphs shall be achieved by raising the sealchamber pressure to the required pressure. The first choice is to apply seal flush plan 11for a hydraulically balanced pump impeller or plan 13 for a hydraulically unbalanced im-peller design. Alternatively the margin may be achieved by lowering the seal chambertemperature by applying seal flush plan 21 or 23.

If the pump differential head is too low to achieve the above required margins, the MAN-UFACTURER shall provide alternative proposals, subject to the approval of COMPANY,in order to ensure an adequate seal environment.

6.1.2.15 [Add the following after -to isolate the seal chamber fluid; and/or:] - to control the flow inconjunction with a fixed orifice in the seal flush supply or return line

[Delete] -to control the flow into or out of the seal chamber

[Add] A throat bushing shall not be used to control the flow into or out of the seal cham-ber. For this purpose a fixed orifice shall be provided to restrict the circulation of theflushing liquid.

6.1.2.19 [Add] Unless otherwise specified, the connection between the seal flush piping and thegland plate shall be full penetration butt welded if the pressure class of the pump flangesis ANSI rating class 900 or higher.

6.1.2.20. b [Add] For vertical pumps, the vent connection shall be provided with a flanged valve andblind. The vent valve and blind flange shall be AISI 316L stainless steel unless otherwisespecified by COMPANY.

Seal gland plates shall have a drain connection if they have a throttle bushing or an aux-iliary sealing device.

6.1.2.23 [Add at the beginning of the clause] Premium carbon floating throttle bushing shall befurnished for both single and dual seals.

6.1.3 Cartridge Seal Sleeves

6.1.3.1 [Add] In applications where the shaft requires additional corrosion protection, an inter-mediate sleeve of the same material as the seal shaft sleeve shall be provided between

the impeller and the seal shaft sleeve. Appropriate secondary (O-ring) sealing devicesshall be installed between the sleeves and the impeller in order to ensure complete pro-tection of the shaft.

6.1.3.3 [Add] Shaft sleeves for pusher type seals shall have a hard face coating at the area ofthe dynamic sealing element, unless otherwise specified or approved by COMPANY.Coatings shall be fully compatible with the pump liquid and the barrier or buffer liquid.

The approval of COMPANY is required for the type of coating and the application proce-dure of the coating for seal sleeves in corrosive services.

6.1.3.5 [Add] If dual pressurized seal arrangements for Category 1 liquids (see paragraph 3.79)are applied, an additional O-ring seal between the shaft and the sleeve shall be locatedat the outboard end of the sleeve. The space in between the two O-rings under thesleeve shall be buffered with the barrier liquid by means of two holes drilled in the shaftsleeve.

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6.1.3.12 [Add] Where seals must seal against an MSSP of more than 50 bar (abs), designs usingset screws for positioning the shaft sleeve are subject to the approval of COMPANY.

6.1.3.13 [Replace] When specified by the purchaser or recommended by the seal MANUFAC-TURER, with the words If the MSSP of the seal exceeds 50 bar (abs),

[Add] Alternative designs to the split ring construction, API 682, page 33, Figure 20, re-quire the specific approval of COMPANY.

6.1.6 Materials

6.1.6.1 General

6.1.6.1.1 [Add] Seal materials shall comply with NACE MR0103, as applicable, for services withH2S levels defined therein. The seal MANUFACTURER shall recommend alternativemechanical seal materials where they consider the specified combination unsuitable. Inall cases, the seal MANUFACTURER shall indicate type, grade and supplier of the mate-rials. Seal types and materials shall be approved by the CONTRACTOR. Solid PTFE O-rings are not acceptable for sealing between the rotating seal parts and the shaft sleeve.

Copper or bronze filled carbon or other copper bearing materials shall not be used forservices involving contact with carbonates, high concentrations of H2S, ammonia, am-monium chloride, and acetylene.

6.1.6.2 Seal Faces

6.1.6.2.3 [Add] Carbon ring material for seal faces shall be suitable for continuous operation at thehighest temperature specified for the pump in which the seal is incorporated. Alternative-

ly, silicon carbide material may be used if approved by COMPANY.

Delete the second sentence if specified

6.1.6.5 Secondary Sealing Components

6.1.6.5.2 [Replace the first sentence by:]

Fluoroelastomers shall not be used in seals operating at a pumping temperature above

175 C. Perfluoroelastomers shall not be used in seals operating at a pumping tempera-

ture above 240 C.

If alternatives are available that are equal to or better than perfluoroelastomers in theapplicable service, they may be applied subject to the approval of COMPANY.

6.1.6.5.4 [New] O-rings made of solid PTFE material shall not be used.

6.1.6.6 Metal Bellows

[Add] Alternative bellows materials for standard seals may be used if they have a provenservice record in the specified duty and if approved by COMPANY.

6.1.6.10.5 [Add] 100% magnetic particle inspection or liquid penetrant inspection of all welds shallbe performed. Requirements of 100% radiographic inspection will be addressed in therequisition/data sheets.

7.0 SPECIFIC SEAL CONFIGURATIONS

7.2 ARRANGEMENT 2SEALS

7.2.1.2 [Delete]

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7.2.1.3 [Replace 1st sentence with] Dual seals with dry running secondary seals are preferred,but shall not be furnished for hazardous services. If dual seals are required, bellows type

dry running seals shall be provided for operating temperatures 150C or higher. All ap-plications for dry running seals shall be approved by the COMPANY.

7.3.1.1 [Add] For dual pressurized systems the barrier medium shall be compatible with the pro-cess fluid, and the barrier pressure shall be controlled between 2 to 4 bars above themaximum seal chamber pressure which can develop at any point on the pump perfor-mance curve.

8.0 ACCESSORIES

8.1 AUXILIARY PIPING SYSTEMS

8.1.3 [Replace with:] Unless specified otherwise, the seal Vendor shall supply all flush coolersand instrumentation associated with the flush plans being applied. Unless specified oth-erwise, the pump Vendor shall supply and fit all orifices, interconnecting pipework andother items associated with the flush plans being applied. All auxiliary piping systems,except Plans 52 and 53 shall be mounted within the confines of the associated pumpsbaseplate area. Plan 52 and Plan 53 systems may be mounted either on or off the pumpbaseplate, as specified on the datasheet. If mounted on the baseplate then the intercon-necting pipework (and associated drain and vent) shall be supplied and fitted by thepump Vendor. If mounted off the baseplate then interconnecting pipework (and associat-ed drain and vent) shall be supplied and installed by the CONTRACTOR, unless speci-fied otherwise.

8.1.5 [Replace with:] Auxiliary piping systems shall not use tubing unless approved by COM-PANY. Piping shall have flanged connections unless otherwise approved by COMPANY.

Primary seal plans, such as 11, 13, 21, 23 and 32, shall be furnished with welded orflanged connected piping.

8.1.8 [Replace the last two sentences of this clause by:]

Threaded connections shall be limited to the final connections at the gland plate only.The last flanged connection before the gland plate shall be made with a lap joint flangeat the gland plate side in order to facilitate proper flange alignment after maintenance.

Pipe bushings and seal welds shall not be used. All fabricated joints in seal system pip-

ing shall be full penetration butt welded and the weld root shall be made by gas tungstenarc welding (GTAW). Socket welds shall be used only with the approval of COMPANY.

8.1.17 [Add to the beginning of the first sentence of this clause:]

"On the gland plate, ...."

8.1.20 [New] If the outside temperature of seal system piping and its components is higher than70 C, personnel protection shall be provided for parts which are within the reach of per-sonnel.

8.2 MECHANICAL SEAL FLUSH/COOLING SYSTEMS (GROUP I)

8.2.1 [Add] However, the seal MANUFACTURER shall remain responsible for the combinedperformance of the seal and seal system in accordance with this specification.

Standard seal flush plans 1, 2, 12, 14, 22, 31, 41 and 53C shall not be used.

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This Specification provides replacement piping and instrumentation schematics for G.14(Plan 52), G.16 (Plan 53B), and G.18 (Plan 54).

For the following services, a suitable clean liquid from an external source shall be inject-ed per Plan 32. The source shall be reliable and available continuously, including duringstart-up and shut down.

a. Very dirty liquids

b. Very corrosive liquids for which suitable seal materials are not available

c. Toxic materials

8.3 QUENCH SYSTEM (GROUP II)

[New]d. Seal quench piping shall include a fixed metering orifice for the required quenching

capacity for each mechanical seal. An appropriate steam trap and condensatedrain shall be installed as close as practical to the pump in order to ensure a drysteam supply to the gland plate in the steam piping to the seal.

e. The quench drain shall be piped to the base plate drain.

8.4 COOLING WATER SYSTEMS (GROUP III)

8.4.1 [Replace with] Details of Cooling Water System are as given in Basic Engineering andDesign Data.

8.4.3 [Replace] Sight flow indicators (closed type) shall be furnished in each outlet line.

8.4.4 [Replace] Vendor shall provide manifolded and valved inlet and outlet connections at theedge of the baseplate for single point connection by the purchaser.

8.5 ACCESSORIESANDAUXILIARY SYSTEM COMPONENTS

8.5.1 Cyclone Separator

[Replace this whole clause, from 8.5.1.1 to 8.5.1.4 inclusive, with:]

Cyclone separators shall not be used unless approved by COMPANY for a specific ap-plication.

Cyclones integral with the pump casing are not permitted. Cyclones in flushing lines

may be used only with approval of the COMPANY and where the MANUFACTURER candemonstrate satisfactory performance. (Note: Although definitive limits cannot be given,the PURCHASER may approve the use of cyclones only where there is a low concentra-tion of high density solids and there is a marked difference in density between the liquidand the solids.) Strainers shall not be used in the recirculation line.

8.5.3 Seal Flush Coolers

8.5.3.1 [Add] Coolers can be either water-cooled or air-cooled. For plans 21, 23, 52 and 53M(modified), air cooling shall be the first choice. Water cooling for Plan 53M (modified) inhazardous services is subject to the approval of COMPANY.

8.5.3.2 [New] The construction of the cooler and its piping configuration shall allow full accessi-bility to the cooling water side for cleaning purposes.

8.5.4 Barrier/Buffer Fluid Reservoirs/Accumulators

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[Add] Liquid barrier seal systems shall be in accordance with paragraph 8.2.The type of barrier seal system arrangement shall be specified on the mechanical sealdata sheet. A dual seal barrier system may contain either a fluid or a clean dry inert gas(e.g. nitrogen) in a dual pressurized gas seal application or a dry gas back-up seal appli-cation.

8.5.4.1 [Add] Make up barrier fluid connections shall be provided so that each connection is col-our coded and unique to a barrier fluid. The requirement is to minimize the risk of usingan incorrect barrier fluid for topping up.

8.5.4.2 [Add at the end of the sentence] ",where applicable for the selected seal barrier system".

[Delete] Figure G.27

a) [Replace this clause by:]

Plan 52 systems shall be provided with a separate reservoir for each seal.

Plan 53 M (modified) systemsshall be provided with a separate accumulator foreach seal.

c) [Modify] 1 meter (3 feet) to 1.5 meters (5 feet).

d) [Add] In order to minimize the pressure drop within the system, pipework shall benot less than 3/4 inch diameter.

f) [Add] A means of filling and re-charging the seal system shall be provided. Refer toAnnex G.37 for details of scope.

Seal vendors are to review the pipework and fittings used in the construction of theseal support piping systems and confirm that the circulating device recommendedcan achieve the required flow rates with the proposed seal buffer fluid.

h) [Replace] Switch with Transmitter. [Modify the last sentence] The transmittershall provide indication and alarm on an increasing (High) pressure. In addition forpressurized dual mechanical seals (Arrangement 3), an alarm on Low pressureshall also be provided. CONTRACTOR shall provide a selector switch in the plantcontrol system to use these signals either for alarm only or for alarm and trip.

i) [Replace with] The reservoir shall be equipped with a level transmitter with level in-dication, low level alarm and high level alarm. The transmitter shall be mounted in

a standpipe arrangement with isolation, drain and vent valves for maintenance.CONTRACTOR shall provide a selector switch in the plant control system to usethese signals either for alarm only or for alarm and trip.

8.5.4.3 [Delete] Figure G.27

a) [Add] Reservoirs for atmospheric or low pressure buffer liquid and accumulators forpressurized barrier liquid shall be sized to allow at least 25 days between manualrefills based on the seal leakage rate specified by the seal MANUFACTURER.This shall not compromise the specified seal life time.

b) The accumulator shall be equipped with a pressure gauge to monitor the Nitrogenpre-charge pressure.

8.5.4.4.4 [Add] The following shall also be stamped on the seal reservoir nameplate: Vessel Tag Number

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Pump Tag Number

Reservoir Capacity

8.5.4.4.9 [Delete] If specified,

8.5.4.4.10 [Replace this clause by:]

All connections to the reservoir shall be provided with weld neck flanges in accordancewith the Specifications stated on the requisition.

8.5.4.4.11 [New] The rating of the reservoir shall be at least equal to the MAWP of the pump casing.

8.5.4.5g [New] The CONTRACTOR shall include a provision enabling back flushing of the coolingcoil.

8.5.4.6 [New] Barrier seal systems are given in clauses 8.2 through 8.4.

The use of any other type of barrier seal system versus those specified below is subjectto COMPANY approval.

Low pressure or non-pressurized buffer liquid systems shall be in accordance with AnnexG.36, plan 52 system.

8.5.4.7 [New] Variable pressure barrier system

API 682 Plan 53M (modified) - Type 1 (see Annex G.32).

For between bearing pumps, each seal shall be individually supported, as shown in An-nex G. 32. (i.e. Annex G33 shall not be used.)

This barrier system is used for dual pressurized seal arrangements. It is typically used inback-to-back or face-to-face seal arrangements where the barrier system pressure issubstantially higher than the normal seal chamber pressure. This system can also beused with dual tandem seals if the individual seal pressure rating permits.

For Category 1 liquids the barrier pressure shall be above the maximum static and dy-namic pressure occurring in the pump in any possible upset condition, such as at pumpmaximum discharge pressure.

For Category 2 and 3 liquids and if applicable, other liquids, the barrier pressure shall beset above the maximum seal chamber pressure that can occur during operation of thepump.

The barrier liquid is normally circulated by a pumping ring and is cooled by a finned tubenatural convection air cooled heat exchanger. The seal MANUFACTURER shall establishthe temperature rise of the liquid and size the cooling system so that the maximum liquidtemperature during operation will not exceed 80 C. If this requirement results in oversizing of the finned tube cooler, water cooled coolers may be considered, subject to theapproval of COMPANY.

The Plan 53M (modified) system uses a bladder-type accumulator that contains a liquidvolume to compensate for the seal leakage across the inboard and outboard seals.

The gas pre-charge pressure of this bladder-type accumulator, when empty of liquid,shall be 1 kg/cm2 higher than the highest pressure that can occur in the pump sealchamber as specified above. Bladder-type accumulators shall be pre-charged with nitro-gen only. The accumulator shell pressure rating shall exceed the maximum possiblesupply pressure of the nitrogen pre-charge supply facilities. Accumulators shall be se-

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lected from the MANUFACTURERs standard range of commercially available pressuredesigns.

The total working volume in the accumulator is the volume required to fill the accumula-tor from empty (with pre-charged nitrogen in the bladder) to the maximum barrier systempressure. Typically this volume results in a pressure increase from 4 to 8 kg/cm2 abovethe nitrogen pre-charge pressure.

The required operating volume of the accumulator is established by the seal leakage rate(inside and outside seal) and the specified refill frequency of the barrier system. This op-erating volume shall be limited to 70% of the total working volume, in order to includeemergency reserve of 30%. This reserve level shall be indicated by means of an appro-priate setting of the low pressure alarm on the system. Unless otherwise approved by

COMPANY, the normal refill interval shall be at least 25 days.

The refill or topping-up of these barrier systems should be done via a hard piped barrierfluid make-up system which has a positive barrier between its fluid supply side and thebarrier fluid header. A typical example is provided in Annex G.37. Each barrier systemshall be connected to the header of this make-up system by means of double blockvalves with a filter in between or spring return ball valves which shall normally be closedand only opened for refilling or topping up. In this way the barrier systems are isolatedfrom each other and cross contamination and pressure disturbance effects are prevent-ed. Depending on location and service conditions, a relief valve may be installed to pre-vent over-pressurising the system on the liquid side.

Unless otherwise approved by COMPANY, individual barrier systems and barrier fluid

make-up systems, including barrier fluid header piping, shall be made of austenitic stain-less steel. Bladder-type accumulator shells may be carbon steel. Bladder materials shallbe MANUFACTURERs standard, unless otherwise specified by COMPANY, and shall becompatible with the barrier liquid.

Each barrier system shall be provided with a permanently attached stainless steel nameplate, which shall indicate at least the following:

Pump item number

Barrier fluid

Pre-charge nitrogen pressure

Minimum and maximum barrier pressure

Pressure alarm setting

Year of construction

Materials of Construction

8.5.4.8 [New] Constant differential pressure ratio barrier system

API 682 Plan 53M (modified) - Type 2 (see Annex G.34).

This sealing system may be used under restricted conditions; it is considered suitableonly for clean and non-aggressive, non-corrosive services, typically in low temperatureservice below minus 25 C.

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The barrier system contains an accumulator with a differential piston-type pressure am-plifier whereby a positive differential pressure across the primary seal is maintained at afixed pressure ratio. This differential pressure is created by the difference between thepiston areas of the barrier liquid side and the process pump side of the amplifier and maybe increased either by a spring or by a weight.

Cooling may be provided by an internal cooler inside the accumulator or by a separatenatural convection fin tube cooler or water cooler.

Since the barrier fluid of this system may be contaminated by the pump liquid, it shall on-ly be applied in those services where contamination is permitted.

Unless otherwise approved by COMPANY, individual barrier systems and barrier fluidmake-up systems, including barrier fluid piping, shall be made of austenitic stainlesssteel.

8.5.4.9 [New] Circulation barrier system

API 682 Plan 54 modified (see Annex G.35).

This barrier system is used for dual pressurised seal arrangements. This system is ap-plied for Category 2 liquids. Subject to COMPANYs approval, it may be used for liquidscontaining H2S in Category 1.

Two basic systems are possible:

1. A once-through circulation barrier system, which is based on a slip stream from theprocess that is returned to the process after having passed through the seals.

2. A full re-circulation system with partial replenishment to maintain the required de-gree of barrier liquid cleanliness.

The systems shall have controlled supply and return pressures. The differential pressurebetween the controlled supply and controlled return pressures shall be between 4kg/cm2 and 6 kg/cm2.

The barrier liquid pressure between the seals shall be set so that leakage of pump liquidinto the barrier system is positively prevented, either dynamically or statically. For thisreason the barrier pressure between the dual seals shall be at least 2 kg/cm2 higherthan the maximum pressure that can occur in the pump seal chamber. As far as practi-cal, this maximum pressure shall be the highest discharge pressure of all pumps con-

nected to the system, but allowance may be made for the maximum reverse pressurecapabilities of the inner seal in static condition. The use of dual pressurised tandem sealsmay also be considered in order to maintain the inner seal integrity during upset condi-tions.

The barrier liquid pressure between the seals for plan 54 circulation systems should notexceed 26 kg/cm2(a). If higher pressures are required, the use of individual circulationsystems or special plan 53M (modified), Type 1, arrangements should be evaluated.

In the design of a barrier system for multiple pumps, careful consideration shall be givento the inclusion of high pressure multi-stage pumps. As these high pressure pumps are apotential contamination hazard for the barrier system, the use of dedicated barrier sys-tems for these pumps should be considered. If these pumps are in non-spared essential

service, separate barrier systems shall be the first choice.

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The barrier system shall be designed so that each seal cartridge has alarms to indicateeither a primary or secondary seal failure and loss of barrier pressure.

The filtration of the barrier liquid shall be 50 m. The system shall have full flow doublefilters with continuous transfer valves.

Each seal cartridge shall include a block valve, non-return valve, flow indicator, re-striction orifice, dual seal, pressure indicator and alarm and restriction orifice (AnnexG.35).

The circulating seal liquid stream may be totally or partially routed back to the process byothers. Depending on the degree of contamination a run-down connection for piping byothers to the slops systems shall also be provided to flush the system.

The system shall be equipped to detect major seal leakage by measuring the supply andreturn flows of the barrier system and/or tank level.

The operating temperature may vary depending on the selected barrier liquid. If required,insulation and heat tracing of supply and return lines shall be provided to prevent exces-sive viscosities during start up and/or during off-design conditions. Unless otherwise ap-proved by COMPANY, the total system including all supply and return piping shall bemade of austenitic stainless steel, except for the booster pumps.

8.5.5.1 [Delete]

8.5.5.2 [Replace with:] The seal Vendor shall select and recommend the barrier/buffer fluid andseek COMPANY and CONTRACTOR approval with regard to availability and compatibil-

ity with process fluid.

8.6 BARRIER/BUFFER FLUID AND SEAL FLUSH POSITIVE CIRCULATING DEVICES

8.6.1 [Replace the last sentence of this clause by:]

The purchaser and mechanical seal MANUFACTURER shall agree upon which type ofcirculating device shall be provided. The seal MANUFACTURER remains responsible forthe performance of the seal and seal system in accordance with this specification.

8.6.2.1 [Add to the end of this clause:]

However, this is not limited to Figures G.29 and G.30.

8.6.2.2 [Add] Seal vendors shall provide the performance curve for head versus flow for the rec-

ommended circulating device.8.6.3.1 [Replace the last sentence of this clause by:]

The circulation pump, provided by others, shall be selected by the MANUFACTURER.The type of pump is subject to the approval of COMPANY.

8.6.4.1 [After the first sentence of this clause, add new sentence:]

The seal MANUFACTURER shall investigate these characteristics for final acceptance ofthe fluid to be applied.

8.6.4.2 [Delete] If specified, [Add] The seal Vendor shall confirm suitability of the selected ex-ternal flush fluid.

8.6.5.2e Replace Switch, with Transmitter8.6.5.3 Replace Switch, with Transmitter

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8.6.5.4 [Add] All containment seal systems shall be provided with a test connection and a testingkit. The testing kit scope shall be as defined in Figure 1.

8.6.6.1 [Add] Barrier/buffer gas system connections shall be routed so that they are accessibleto operators standing at grade level alongside the seal system.

8.6.6.2 Replace Switch, with Transmitter

9.0 INSTRUMENTATION

[Delete entire sections 9.1 through 9.10]

[Add] All instrumentation shall be provided as per Specification DGS-IU-007. Whereverswitches are referred to, transmitters are to be supplied.

All controls and instruments shall be located no higher than 1.8 m above grade, in orderto permit easy visibility by the operators, as well as accessibility for tests, adjustments,and maintenance.

Where it is envisaged that ladders will be required, the vendor shall supply a safe work-

ing platform with stairs to reach the working platform.

10.0 INSPECTION, TESTING AND PREPARATION FOR SHIPMENT

10.1 GENERAL

10.1.7 [Modify the first part of sentence from:] If specified, the purchaser, the vendor, or bothto The COMPANY, CONTRACTOR and the VENDOR

10.2 INSPECTION

10.2.3k [Add] As a minimum, hardness shall be verified where similar requirements have beenspecified for wetted components of the pump on the pump data sheet.

10.3 TESTING

10.3.5.1 [Add to the beginning of the paragraph:] For dual seals or

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11.0 DATA TRANSFER11.1 GENERAL

11.1.2 [Add] If requested by COMPANY for specific critical pump sealing seal applications, theseal MANUFACTURER shall provide data on the selected type and grade of the materi-als used for the seal faces and gaskets and on the materials supplied by the SUB-SUPPLIER/MANUFACTURER. It is recognized that this information is not part of thenormally supplied seal data and, as such, the contents and details shall be agreed uponby COMPANY and the seal MANUFACTURER.

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APPENDIX 1 SEAL SELECTION PHILOSOPHY

FOLLOWING ARE THE GENERAL GUIDELINES FOR SEAL SELECTION GIVING MIN-IMUM CRITERIA. FINAL SEAL SELECTION SHALL BE THE JOINT RESPONSIBILITYOF THE PUMP VENDOR AND SEAL VENDOR

Sr No ServicePumpingTemperatureRange

Comments

API 682 Seal Code & Flush Plans

Notes

Catego-ry

TypeAr-

rangement

Config-uration

Prima-ry

FlushPlan

Second-ary Flush

Plan

1 Fresh water,condensate 0-80 C 2 A 1 CW-FL 11 61M

2Fresh water,condensate

81-100 C 2 A 1 CW-FL 23 61M

3 Sea Water 0-80 C 2 A 1 CW-FL 1161MNote

62 May berequired, con-firm metallurgy

4Boiler FeedWater

80-290 C 2 A 1 CW-FL 23 61M

5Sour WaterH2S >50 ppm200 ppm500 ppm2000ppm

0-80 C 3 A 3 CW-FB 2 53note NACErequirement

9Brine to max60g/litre

0-60 C 2 A 1 CW-FL 11 62Consider Plan

32

10Oily Water -Sump applica-tions

VS4Pumps

2 A 1 NC-FX 2

Packed Gland,Dry RunningContacting

Seal

11Storm Water -Sump applica-tions

VS4Pumps

2 A 1 NC-FX 2

Packed Gland,Dry RunningContactingSeal

12Sea Water -Sump applica-tions

VS4Pumps

2 A 1 NC-FX 2

Packed Gland,Dry RunningContactingSeal

13

Hydrocarbon -Non Flashing -Sump applica-tions

VS4Pumps

2 A 1 NC-FX 2

14

Hydrocarbon -Flashing -Sump applica-

tions

VS4Pumps

2 A 1 CW-BB 2 53

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15

Hydrocabon -Non Flashingwith H2S (lowlevels below200 ppm)

2 A 1 CS-FX 2

16Sea Water -Vertical Lift

1 A 1 CW-FL 32Clean Waterflush

17 Cooling Water 0-80 C 2 A 1 CW-FL 11 61M

18Process Wa-ter

0-80 C 2 A 1 CW-FL 11 61M

Check con-taiminants anddiscuss withpump / sealvendor

19Hydrocarbons- Non Flashing

-40 C to -5 C 2 A 2 CW-NC 11 72&75

note check forhazardousliquid if yesuse dual pres-suirsed seal.


-6 C to 175C

2 A 1 CW-FL 11 61M


176 C to 400C

2 C 3 CW-BB 2 53


to a max of400 C

Aboveauto igni-tion tem-perature

3 C 3 CW-BB 2 53

23Hydrocarbons- Flashing -5 C to 59 C 2 A 2 CW-CS 11 76

24Hydrocarbons- Flashing

60 C to 175C

2 A 3 CW-BB 2 Note 53Consider Plan23


176 C to400C

2 C 3 CW-BB 2 Note 53Consider Plan23


to a max of400 C

Aboveauto igni-tion tem-perature

3 C 3 CW-BB 23 53

27 HydrocarbonsContami-nated withH2S

as a minimum follow Sour Water with ppm H2S or hydrocar-bon at operating temperature

28 HydrocarbonsContami-nated withBenzene

2 A 3 CW-BB 2 53

Examples of Hydrocarbon Services

29 Naphtha 0-80 C 2 A 1 CW-CS 11 76

Check withprocess forH2S or Ben-zene present

30Propane /Butane

0-80 C 2 A 3 CW-FB 11 53

31 Crude Oil 0-80 C 2 A 1 CW-FL 11 65

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32 Crude Oil >200 C Possibilityof Coking

2 A 3 CW-FB 2 53

33 Diesel Oil 0-80 C 2 A 1 CW-FL 11 61M

34 Kerosene 0-80 C 2 A 1 CW-FL 11 61M

35Molten Sul-phur

127 C Horizontal 2 A 1 CW-FL 11 62

Steam QuenchConsider alsoa Hydrody-namic Seal

36Molten Sul-phur

127 C VS4 - - - - - - Packed Gland

37 Corrosive Acid 0-80 C 2 A 3 CW-FB 2 53

38 Sulphuric Acid 0-80 C 2 A 1 CW-FL 11 61

39HydrofluoricAcid

0-80 C Work with Pump Vendor / Seal Vendor

40NAOH (Lowconcentra-tions)

0-80 C 2 A 1 CW-FL 11 62

41NAOH (HighConcentra-tions)

0-80 C 2 A 3 CW-FB 2 53

42 Benzene 0-80 C 2 A 3 CW-BB 2 53

43 Amines 0-240 C 2 A 3 CW-BB 2 53

44 Lean MEG 0-80 C 2 A 3 CW-BB 2 53

45 Rich MEG 0-80 C 2 A 3 CW-BB 2 53

46 FCC Slurries up to 350 C Work with Pump Vendor / Seal Vendor

47Viscous Appli-cations 0-80 C Work with Pump Vendor / Seal Vendor

48 Dirty Service 0-80 C Work with Pump Vendor / Seal Vendor

Dual Non Pressurised Seals shall be supplied in the following services:

Hazardous services

Services where a five year operation cannot be achieved with a single seal

Dual Pressurised Seals shall be applied for the following services as a minimum

Services where it is not permitted for the pumped liquid to enter the flare or atmosphere

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If the available seal liquids are not compatible with the required seal conditions to obtain a 5 year life

Hazardous and Toxic services

Services containing H2S which upon seal failure result in an H2S leakage rate to atmosphere exceeding 1 g/s.

Fluids with a SG less than 0.7

Operating temperatures higher than 200 C

Dry gas Seal Arrangements in pumps versus standard dual seal applications are subject to Company approval and shall be limited to

A single liquid seal and a dry gas back up seal arrangement may be considered only for liquids not defined asCategory 3

Dual pressurised dry gas seal arrangements with a pressurised Nitrogen barrier may only be considered for liq-uids that are not considered as hazardous, and have a maximum vapour pressure at pumping temperature of1.05 bar(abs)

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[ADD] ANNEX A RECOMMENDED SEAL SELECTION PROCEDURE

(Part 1 of 2)

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[ADD] ANNEX A RECOMMENDED SEAL SELECTION PROCEDURE(Part 2 of 2)

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[ADD] ANNEX A, SHEET 10 OF 10, (SI UNITS, PAGE 102)

BARRIER/BUFFER FLUID SELECTION CRITERIA

In addition the following shall be required for barrier liquid for pressurized dual seals:

1) The barrier liquid shall be fully compatible with the pumped liquid (it is acceptable if itwere to leak into the pumped liquid). The barrier liquid shall be suitable for leakage intothe atmosphere and shall not create a hazardous situation or be considered environmen-tally unacceptable.

2) The barrier liquid shall be able to withstand the maximum and minimum pumping tem-perature without decomposing or forming solids and/or corrosive/erosive components. It

shall have an adequate viscosity at the minimum and maximum pumping temperature.3) The barrier liquid shall be fully compatible with all materials used in the seals and the

seal piping and piping components.

4) The barrier liquid shall provide adequate lubrication to the seal faces in order to ensurecontinuous pump operation for at least five years.

For unpressurized or low pressure dual seals the following shall be required for the selectionof the buffer liquid:

1) The buffer liquid shall be fully compatible with the pumped liquid. The barrier liquid shallbe suitable for leakage into the atmosphere and shall not create a hazardous situation orbe considered environmentally unacceptable.

2) The buffer liquid shall be able to withstand the maximum and minimum pumping temper-ature without decomposing or forming solids and/or corrosive/erosive components. Itshall have an adequate viscosity at the minimum and maximum pumping temperature.

3) The buffer liquid shall be fully compatible with all materials used in the seals and the sealpiping and piping components.

4) The buffer liquid shall provide adequate lubrication to the seal faces in order to ensurecontinuous operating of at least five years. The liquid shall be checked for its suitabilityas a buffer fluid when it is saturated with the pumped liquid.

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[MODIFY]

ANNEX G.19 API 682 plan 61 modified

Drain connection shall be fitted with a stub pipe. If the seal leaks, fluid will escapepast the throttle bush and cover the pump and surrounding area with fluid. By fittingthe drainpipe, leakage will be directed to the base plate and a visual indication ofleakage will also be given.

[MODIFY]


Test connection and test kit to check the integrity of the containment seal to be pro-vided.

[MODIFY]


Test connection and test kit to check the integrity of the containment seal to be pro-vided.

[MODIFY]


Test connection and test kit shall be provided.

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[ADD]

ANNEX G.32 API 682 PLAN 53 MODIFIED, TYPE 1 WITH AIR FIN TUBE (NATURALCONVECTION) OR WATER COOLING

NOTE:

Annex G.32 shal l be used for each seal on between bearing (BB) type pumps.

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[ADD]ANNEX G.33 API 682 PLAN 53 MODIFIED, TYPE 1 WITH AIR FIN TUBE (NATURAL

CIRCULATION) OR WATER COOLING FOR BETWEEN BEARINGS PUMP

NOTE:

Delete this Annex G.33


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[ADD]

ANNEX G.34 API 682 PLAN 53 MODIFIED, TYPE 2 WITH AIR FIN TUBE (NATURALCIRCULATION) OR WATER COOLING

NOTE:



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[ADD]

ANNEX G.35 API 682 PLAN 54 MODIFIED

Non Return

Valve

NOTE: Supply pumps are provided by others

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[ADD]

ANNEX G.36 API 682 PLAN 52

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[ADD]ANNEX G.37 MAKE-UP SYSTEM FOR API PLAN 53 Modif ied AND/OR 52 SEAL SYS-

TEMS

RESERVOIR

RECIRCULATINGPUMP

Liters

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ADDENDUM SHEET

All revisions to this DGS subsequent to the issue of Rev Zero shall be recorded in this addendumsheet and shall be incorporated into the DGS in the next revision.

Date Proposed Revision Remarks

June 2009 PART II AMENDMENTS / SUPPLEMENTS TO API 682

In Section # 1.0:

Amend second sentence of second paragraph as:

The applications addressed in this specification cover sealing

duties for pumps with a working temperature range of -40 to+400 C and a maximum allowable working pressure up to 42bar (abs). It covers seals for pump shaft diameters from 20 mmto 110 mm. Seal applications outside these boundaries aresubject to the same design and configuration, shall be termedas Engineered Seals and shall require COMPANY's approv-al.

In Section # 2.0:

Add fol lowing:

American Standards:API 682 Shaft Sealing Systems for Centrifugal and Ro-

tary Pumps

British Standards:

BS EN 10204 Metallic Materials Types of Inspection Docu-ments

In Clause # 1.4:

Add [Add] Refer to Appendix 1 Seal Selection Philosophyfor general guidelines on seal selection.

In Clause # 4.2.3:

Delete this Clause in totality [New] Annex B provides specificapplication details and material requirements for severalpumped fluid applications. The seal MANUFACTURER maypropose alternatives to these requirements, subject to approvalof COMPANY.

Incorporated inRevision 1

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In Clause # 6.1.1.6:Replace this Clause [Replace the last sentence by] All com-ponents, including the seal and flush systems, shall be de-signed for the Maximum Allowable Case Working Pressure(MACWP) of the pump. The seals dynamic pressure rating atthe specified service conditions shall not be less than the max-imum discharge pressure of the pump.

With [Replace the last sentence by] The static sealing pres-sure rating (SSPR) of mechanical seals shall be greater thanor equal to the maximum static sealing pressure (MSSP),which shall be calculated as indicated below.

For Arrangement 1 seals, the MSSP of each seal shall beequal to the maximum static seal chamber pressure that canoccur in the pump. Unless otherwise specified, this shall be theshut-off pressure of the pump at maximum suction pressure.

For Arrangement 2 seals, the MSSP of both the inner and out-er seal shall be equal to the maximum static seal chamberpressure that can occur in the pump. Unless otherwise speci-fied, this shall be the shut-off pressure of the pump at maxi-mum suction pressure.

For Arrangement 3 seals, the MSSP of the outer seal shall beequal to the maximum static seal chamber pressure that can

occur in the pump. Unless otherwise specified, this shall be thegreater of 1) shut-off pressure of the pump at maximum suctionpressure or 2) the maximum barrier fluid pressure. The MSSPof the inner seal shall be the greater of 1) differential betweenthe maximum barrier fluid pressure and the minimum sealchamber pressure or 2) the maximum differential betweenmaximum seal barrier fluid pressure and atmospheric pres-sure.

In Clause # 4.2.3:

Delete this Clause in totality [Add] The Maximum StaticSealing Pressure (MSSP) OF Mechanical Seals shall be at least

as indicated below:

For single seals and dual seals in tandem, the MSSP ofeach seal shall be at least equal to the maximum staticpump seal chamber pressure. Unless otherwise speci-fied, this shall be the shut off pressure of the pump atmaximum suction pressure.

For dual seals in back to back or face to face arrange-ment, the MSSP of the outer seal shall be at least equalto the maximum static seal chamber pressure in thepump. Unless otherwise specified, this shall be the shutoff pressure of the pump at maximum suction pres-sure.

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Add new Clause # 8.1.3:

[Replace with:] Unless specified otherwise, the seal Vendorshall supply all flush coolers and instrumentation associatedwith the flush plans being applied. Unless specified otherwise,the pump Vendor shall supply and fit all orifices, interconnect-ing pipework and other items associated with the flush plansbeing applied. All auxiliary piping systems, except Plans 52and 53 shall be mounted within the confines of the associatedpumps baseplate area. Plan 52 and Plan 53 systems may bemounted either on or off the pump baseplate, as specified on

the datasheet. If mounted on the baseplate then the intercon-necting pipework (and associated drain and vent) shall be sup-plied and fitted by the pump Vendor. If mounted off thebaseplate then interconnecting pipework (and associated drainand vent) shall be supplied and installed by the CONTRAC-TOR, unless specified otherwise.

In Clause # 8.1.8:

Add in second paragraph All fabricated joints in seal systempiping shall be full penetration butt welded and the weld rootshall be made by gas tungsten arc welding (GTAW).

In Clause # 8.2.1:

Add This Specification provides replacement piping and in-strumentation schematics for G.14 (Plan 52), G.16 (Plan 53B),and G.18 (Plan 54).

Add new Clause # 8.4.1:

[Replace with] Details of Cooling Water System are as givenin Basic Engineering and Design Data.

In Clause # 8.5.3.1:

Add Coolers can be either water-cooled or air-cooled.

Add new Clause # 8.5.4.1:

[Add] Make up barrier fluid connections shall be provided sothat each connection is colour coded and unique to a barrierfluid. The requirement is to minimize the risk of using an incor-

rect barrier fluid for topping up.

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In Item # a), Replace pump With seal

Add fol lowing new Items:

d) [Add] In order to minimize the pressure dropwithin the system, pipework shall be not lessthan 3/4 inch diameter.

f) [Add] A means of filling and re-charging theseal system shall be provided. Refer to AnnexG.37 for details of scope.

Seal vendors are to review the pipework andfittings used in the construction of the sealsupport piping systems and confirm that thecirculating device recommended can achievethe required flow rates with the proposed sealbuffer fluid.

Add new Clause # 8.5.4.4.11:

[New] The rating of the reservoir shall be at least equal to theMAWP of the pump casing.

Add new Clause # 8.5.4.5g:

[New] The rating of the reservoir shall be at least equal to theMAWP of the pump casing.


Delete from f irst sentence and G.33

Add For between bearing pumps, each seal shall be individu-ally supported, as shown in Annex G. 32. (i.e. Annex G33 shall

not be used.)


[Add] Seal vendors shall provide the performance curve forhead versus flow for the recommended circulating device.

Add new Clause # 8.6.5.2e:

Replace Switch, with Transmitter

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Add new Clause # 8.6.5.3: Replace Switch, with Transmitter


[Add] All containment seal systems shall be provided with atest connection and a testing kit. The testing kit scope shall beas defined in Figure 1.


[Add] Barrier/buffer gas system connections shall be routedso that they are accessible to operators standing at grade levelalongside the seal system.


Replace Switch, with Transmitter

In Section # 9.0:

Add Wherever switches are referred to, transmitters are to besupplied.

All controls and instruments shall be located no higher than 1.8m above grade, in order to permit easy visibility by the opera-tors, as well as accessibility for tests, adjustments, andmaintenance.

Where it is envisaged that ladders will be required, the vendorshall supply a safe working platform with stairs to reach theworking platform.

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Add new Appendix:APPENDIX 1 SEAL SELECTION PHILOSOPHY

In Annex A:

Replace 3 years With 5 years

Delete Annex B Typical Materials Standards for SealChambers and Mechanical Seal Components

In Annex G:

Add

[MODIFY]


Drain connection shall be fitted with a stubpipe. If the seal leaks, fluid will escape past thethrottle bush and cover the pump and surround-ing area with fluid. By fitting the drainpipe,

leakage will be directed to the base plate and avisual indication of leakage will also be given.

[MODIFY]


Test connection and test kit to check the integri-ty of the containment seal to be provided.

[MODIFY]


A test connection and test kit to check the integ-rity of the containment seal to be provided.

[MODIFY]


A test connection and test kit SHALL be provid-ed.

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In Annex G.32:Delete Optional from TI

Add

Note:Annex G.32 shall be used for each seal on between bearing(BB) type pumps.

In Annex G.33:

Add

Note:Delete this Annex G.33

Annex G.32 shall be used for each seal on between bearing(BB) type pumps.

In Annex G.34:

Add

Note:


Annex G.32 shall be used for each seal on between bearing(BB) type pumps.

In Annex G.36:

Delete Optional from TI

Add High to LA

Dec 2013 Add the following Clause No. 8.5.4.3 (b) to Clause No.8.5.4.3 (Accumulator sizing):

Clause No. 8.5.4.3 (b): the accumulator shall be equipped witha pressure gauge to monitor the Nitrogen precharge pressure.

Clause No. 1.0 Scope Add the fol lowing sentence to the endof 2nd paragraph of Clause No. 1.0:

The seal Vendor shall supply references of seals in similar ser-vices.

Incorporated inrevision 2

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Clause No. 3.0 Defini tions Add fol lowing new defini tions:

3.82 Plan 54 (Plant wide): Is a plan 54 where the external sealflush is supplied from plant-wide system engineered and sup-plied by the buyer.

3.83 Plan 54 (Stand-alone): Is a plan 54 where the external sealflush is supplied from a Stand-alone seal support console engi-neered and supplied by the seal supplier. There will be one suchconsole per pump. The external flush fluid shall have dual

pumps, one running and one stand by.

DGS-MU-017 - Rev 2

Documents

Transcript of DGS-MU-017 - Rev 2