32451010_Spec_2011-02_A02.pdf

DEP SPECIFICATION

INSTRUMENTATION OF DEPRESSURING SYSTEMS

DEP 32.45.10.10-Gen.

February 2011

(DEP Circular 49/11 has been incorporated)

(Amendment A01 has been incorporated February 2013)

ECCN EAR99

DESIGN AND ENGINEERING PRACTICE

DEM1

2011 Shell Group of companies All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, published or transmitted, in any form or by any means, without the prior

written permission of the copyright owner or Shell Global Solutions International BV.

This document contains information that is classified as EAR99 and, as a consequence, can neither be exported nor re-exported to any country which is under an embargo of the U.S. government pursuant to Part 746 of the Export Administration Regulations (15 C.F R. Part 746) nor can be made available to any national of such country. In addition, the information in this document cannot be exported nor re-exported to an end-user or for an end-use that is prohibited by Part 744 of the Export

Administration Regulations (15 C.F.R. Part 744).

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This document has been supplied under license by Shell to:Chiyoda Malaysia Sdn. Bhd. [email protected] 18/05/2015 10:43:57

ECCN EAR99 DEP 32.45.10.10-Gen. February 2011

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PREFACE

DEP (Design and Engineering Practice) publications reflect the views, at the time of publication, of Shell Global Solutions International B.V. (Shell GSI) and, in some cases, of other Shell Companies.

These views are based on the experience acquired during involvement with the design, construction, operation and maintenance of processing units and facilities. Where deemed appropriate DEPs are based on, or reference international, regional, national and industry standards.

The objective is to set the recommended standard for good design and engineering practice to be applied by Shell companies in oil and gas production, oil refining, gas handling, gasification, chemical processing, or any other such facility, and thereby to help achieve maximum technical and economic benefit from standardization.

The information set forth in these publications is provided to Shell companies for their consideration and decision to implement. This is of particular importance where DEPs may not cover every requirement or diversity of condition at each locality. The system of DEPs is expected to be sufficiently flexible to allow individual Operating Units to adapt the information set forth in DEPs to their own environment and requirements.

When Contractors or Manufacturers/Suppliers use DEPs, they shall be solely responsible for such use, including the quality of their work and the attainment of the required design and engineering standards. In particular, for those requirements not specifically covered, the Principal will typically expect them to follow those design and engineering practices that will achieve at least the same level of integrity as reflected in the DEPs. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from his own respons bility, consult the Principal.

The right to obtain and to use DEPs is restricted, and is typically granted by Shell GSI (and in some cases by other Shell Companies) under a Service Agreement or a License Agreement. This right is granted primarily to Shell companies and other companies receiving technical advice and services from Shell GSI or another Shell Company. Consequently, three categories of users of DEPs can be distinguished:

1) Operating Units having a Service Agreement with Shell GSI or another Shell Company. The use of DEPs by these Operating Units is subject in all respects to the terms and conditions of the relevant Service Agreement.

2) Other parties who are authorised to use DEPs subject to appropriate contractual arrangements (whether as part of a Service Agreement or otherwise).

3) Contractors/subcontractors and Manufacturers/Suppliers under a contract with users referred to under 1) or 2) which requires that tenders for projects, materials supplied or - generally - work performed on behalf of the said users comply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements with users, Shell GSI disclaims any liability of whatsoever nature for any damage (including injury or death) suffered by any company or person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination of DEPs or any part thereof, even if it is wholly or partly caused by negligence on the part of Shell GSI or other Shell Company. The benefit of this disclaimer shall inure in all respects to Shell GSI and/or any Shell Company, or companies affiliated to these companies, that may issue DEPs or advise or require the use of DEPs.

Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall not, without the prior written consent of Shell GSI, be disclosed by users to any company or person whomsoever and the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be returned after use, including any copies which shall only be made by users with the express prior written consent of Shell GSI. The copyright of DEPs vests in Shell Group of companies. Users shall arrange for DEPs to be held in safe custody and Shell GSI may at any time require information satisfactory to them in order to ascertain how users implement this requirement.

All administrative queries should be directed to the DEP Administrator in Shell GSI.



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TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................ 4 1.1 SCOPE ........................................................................................................................ 4 1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS ......... 4 1.3 DEFINITIONS ............................................................................................................. 4 1.4 CROSS-REFERENCES ............................................................................................. 5 1.5 SUMMARY OF MAIN CHANGES ............................................................................... 5 1.6 COMMENTS ON THIS DEP ....................................................................................... 6 1.7 DUAL UNITS ............................................................................................................... 6

2. DEPRESSURING SYSTEMS ..................................................................................... 7 2.1. GENERAL ................................................................................................................... 7 2.2. HIGH-RATE EMERGENCY DEPRESSURING .......................................................... 7 2.3 LOW-RATE OPERATIONAL DEPRESSURING ........................................................ 7 2.4 HIERARCHY OF OPERATION................................................................................... 7 2.5 REQUIREMENTS FOR HUMAN-MACHINE INTERFACE ......................................... 7

3. SPECIFIC DESIGN AND CONSTRUCTION REQUIREMENTS ............................... 8 3.1 DEPRESSURING VALVES ........................................................................................ 8 3.2 SECURE INSTRUMENT AIR SYSTEM ..................................................................... 8 3.3 INSTRUMENT AIR LINES .......................................................................................... 9 3.4 SOLENOID VALVES .................................................................................................. 9 3.5 FIRE PROOFING ........................................................................................................ 9 3.6 TEST FACILITIES ..................................................................................................... 10 3.7 HANDSHAKE FOR CRITICAL INFORMATION TO OTHER PROCESSES ............ 10 3.8 VALIDATION ............................................................................................................. 10

4. REFERENCES ......................................................................................................... 11



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1. INTRODUCTION

1.1 SCOPE

This DEP specifies requirements for the instrumentation of depressuring systems, covering both high-rate emergency depressuring and low-rate operational depressuring. Refer to DEP 80.45.10.12-Gen. for the application of emergency depressuring systems.

This DEP is intended to be used in conjunction with other DEP documents, particularly DEP 32.31.00.32-Gen., DEP 32.36.01.17-Gen., DEP 32.80.10.10-Gen. and DEP 80.45.10.12-Gen.

This DEP contains mandatory requirements to mitigate process safety risks in accordance with Design Engineering Manual DEM 1 Application of Technical Standards.

This is a revision of the DEP of the same number dated January 2010; see (1.5) regarding the changes.

1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by Shell GSI, the distribution of this DEP is confined to Shell companies and, where necessary, to Contractors and Manufacturers/Suppliers nominated by them. Any authorised access to DEPs does not for that reason constitute an authorization to any documents, data or information to which the DEPs may refer.

This DEP is intended for use in facilities related to oil and gas production, gas handling, oil refining, chemical processing, gasification, distribution and supply/marketing. This DEP may also be applied in other similar facilities.

When DEPs are applied, a Management of Change (MOC) process should be implemented; this is of particular importance when existing facilities are to be modified.

If national and/or local regulations exist in which some of the requirements could be more stringent than in this DEP, the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable with regards to the safety, environmental, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this DEP which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned, the objective being to obtain agreement to follow this DEP as closely as possible.

1.3 DEFINITIONS

1.3.1 General definitions

The Contractor is the party that carries out all or part of the design, engineering, procurement, construction, commissioning or management of a project or operation of a facility. The Principal may undertake all or part of the duties of the Contractor.

The Manufacturer/Supplier is the party that manufactures or supplies equipment and services to perform the duties specified by the Contractor.

The Principal is the party that initiates the project and ultimately pays for it. The Principal may also include an agent or consultant authorised to act for, and on behalf of, the Principal.

The word shall indicates a requirement.

The capitalised term SHALL [PS] indicates a process safety requirement.

The word should indicates a recommendation.



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1.3.2 Specific definitions

Term Definition

Depressuring Reducing the pressure in process equipment at a controlled rate, either due to emergency conditions or for operational purposes.

Instrumented Protective System

The electromechanical, electronic and/or programmable electronic Logic Solver component of the Instrumented Protective Function, complete with input and output equipment.

Normally De-energised

De-energised during normal process conditions and when no demand is present.

Normally Energised

Energised during normal process conditions and when no demand is present.

1.3.3 Acronyms

Term Definition

SIA Secure Instrument Air

SIL Safety Integrity Level

UPS Uninterrupted Power Supply

1.4 CROSS-REFERENCES

Where cross-references to other parts of this DEP are made, the referenced section number is shown in brackets. Other documents referenced by this DEP are listed in (4).

1.5 SUMMARY OF MAIN CHANGES

This DEP is a revision of the DEP of the same number dated January 2010. The following are the main, non-editorial changes.

Old section

New section

Change

All All Split in Specification and Informative DEP.

5 3.1 Calculation of depressuring rate and related process parameters deleted.

6.2 3.1 Double acting actuators deleted.

6.3 3.4 Inherent requirements deleted.

6.7 3.2 Design requirements of pressure vessel conform DEP 31.22.10.32-Gen.

6.8 - Requirements for periodic proof testing transferred to RP.

Amendment A02

1.6 1.6 Updated DEP feedback process.

3.2 3.2 Reference to pressure vessel DEPs have been updated to the new pressure vessel DEP 31.22.00.31-Gen.

- 4. Reference to pressure vessel DEPs have been updated to the new pressure vessel DEP 31.22.00.31-Gen.

4. Added DEP feedback form - DEP 00.00.05.80-Gen.



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1.6 COMMENTS ON THIS DEP Amendment A02

Comments on this DEP may be submitted to the Administrator using one of the following options:

Shell DEPs Online

(Users with access to Shell DEPs Online)

Enter the Shell DEPs Online system at https://www.shelldeps.com

Select a DEP and then go to the details screen for that DEP.

Click on the Give feedback link, fill in the online form and submit.

DEP Feedback System (Users with access to Shell Wide Web)

Enter comments directly in the DEP Feedback System which is accessible from the Technical Standards Portal http://sww.shell.com/standards.

Select Submit DEP Feedback, fill in the online form and submit.

DEP Standard Form (Other users)

Use DEP Standard Form 00.00.05.80-Gen. to record feedback and email the form to the Administrator at [email protected].

Feedback that has been registered in the DEP Feedback System by using one of the above options will be reviewed by the DEP Custodian for potential improvements to the DEP.

1.7 DUAL UNITS Amended per Circular 49/11 Dual units have been incorporated throughout this DEP.

This DEP contains both the International System (SI) units, as well as the corresponding US Customary (USC) units, which are given following the SI units in brackets. When agreed by the Principal, the indicated USC values/units may be used.



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2. DEPRESSURING SYSTEMS

2.1. GENERAL

For the application of high-rate and low-rate depressuring systems, see DEP 80.45.10.12-Gen.

Depressuring systems shall be provided with manual trip facilities and with a reset which will allow the operator to close the valve after the trip conditions have cleared. If the depressuring valve is also automatically initiated, then the SIL assessment, design and IPF management SHALL [PS] be in accordance with DEP 32.80.10.10-Gen. The most stringent requirements of this DEP and of DEP 32.80.10.10-Gen. (based on the SIL found) SHALL [PS] be applied.

Survivability requirements to withstand severe accident conditions SHALL [PS] be defined and implemented for depressuring systems.

2.2. HIGH-RATE EMERGENCY DEPRESSURING

The travel time of the depressuring valve assembly in open and close direction - including all auxiliaries and at the maximum upstream and minimum downstream process pressures - shall not exceed 20 seconds.

Manual initiation shall be via a hardwired switch to the Instrumented Protective System. Initiation and reset SHALL [PS] be possible from a safe location. For facilities with a control room, manual initiation and reset shall be from a switch at the operator console. A local emergency depressuring panel shall be provided if required by facility operations philosophies. The open and closed position of the valve shall be indicated at the operator console and local emergency depressuring panel.

High-rate depressuring valves shall be air fail open on/off valves. Acceptable valve styles are ball or high performance butterfly valves.

2.3 LOW-RATE OPERATIONAL DEPRESSURING

The travel time of the depressuring valve assembly in open and close direction - including all auxiliaries and at the maximum upstream and minimum downstream process pressures - shall not exceed 30 seconds when initiated at the manual control station and 20 seconds when initiated automatically.

Low-rate depressuring systems may be equipped with a manual control station to enable partial opening. For facilities with a control room, the depressuring system shall be operable from the operator console. The open and closed position of the valve shall be indicated at the control location.

Low-rate depressuring valves can be air fail open or air fail close on/off or throttling valves. Valve styles shall be globe, ball, or high performance butterfly valves. Globe valves shall be flow to open. Balanced plugs shall not be used. Throttling valves shall be equipped with a positioner.

2.4 HIERARCHY OF OPERATION

Upon initiating high-rate depressuring, the low-rate depressuring system SHALL [PS] be closed automatically. There SHALL [PS] be no provisions to prevent the high-rate valve from opening if the low-rate operational valve does not close.

Upon automatic initiation of the low-rate depressuring system (in case the low rate depressuring valve is also the final element of an IPF), the low-rate depressuring valve SHALL [PS] open fully, unless it is inhibited by high-rate depressuring.

2.5 REQUIREMENTS FOR HUMAN-MACHINE INTERFACE

The pressure in process facilities shall be recorded in the historian of the Distributed Control System during depressurisation events. Additionally, real time data should be gathered by the system to validate the proper function of the depressuring valve.



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3. SPECIFIC DESIGN AND CONSTRUCTION REQUIREMENTS

3.1 DEPRESSURING VALVES

The nominal body size shall be DN 50 (NPS 2) or larger. The valve shall have metal seats and shall be tight shut-off in the forward flow direction in accordance with ISO 5208 leakage class B for ball valves and IEC 60534-4 leakage class V for control valves. Handwheels or provisions for mounting handwheels shall not be provided.

Two valves in series SHALL [PS] not be used.

Valve calculations and selection shall be in accordance with DEP 80.45.10.12-Gen., section 2.9 and DEP 32.36.01.17-Gen., section 8. The actual valve capacity (Cv factor) of the valve SHALL [PS] not be less than the calculated required value, nor shall it exceed this value by more than 10 %. If this results in a non-standard trim size or a special construction, then the actual valve capacity shall be demonstrated by a test in accordance with the control valve capacity test procedure of IEC 60534-2-3. Mechanical maximum travel stops to limit the valve capacity at maximum opening of the valve shall not be used.

The lower design temperature SHALL [PS] be based on the minimum temperature that can be achieved during depressuring. If cooling during depressuring can cause freezing of the stuffing box or ice formation on the stem of valves, then an extended bonnet shall be specified.

The Mach number of the valve body outlet shall not exceed 0.7. For applications where the valve will be used more than 10 times per year, the Mach number shall not exceed 0.3. Limits for the noise generated by valves shall comply with DEP 31.10.00.31-Gen.

The minimum hole and passage way size in low-noise trims SHALL [PS] be 6 mm ( inch) in diameter. Low noise trims, filters restriction plates or silencers SHALL [PS] not be used if there is a potential of plugging.

Throttling depressuring valves shall be in accordance with DEP 32.36.01.17-Gen. Actuators for throttling valves shall be piston type, spring return. Quarter turn on/off actuators shall be spring return and in accordance with DEP 31.40.70.30-Gen., section 5.7. Actuators shall be designed for maximum instrument air pressure without the use of pressure regulating devices. The actuator housing shall be carbon steel or stainless steel.

Valve open/closed position switches or a valve position transmitter shall be used as sensors to indicate valve postion.

3.2 SECURE INSTRUMENT AIR SYSTEM

3.2.1 Application

A Secure Instrument Air (SIA) buffer vessel SHALL [PS] assure instrument air supply to:

Automatically initiated air fail close valves. Air fail open valves if the flare system cannot handle the full depressuring rate of all

depressuring loads simultaneously.

The likelihood and consequences of a spurious opening of other air fail open depressuring valves resulting from loss of instrument air supply shall be assessed. A Secure Instrument Air (SIA) buffer vessel should assure instrument air to such valves if justified by the assessment.

3.2.2 Design requirements

Upon instrument air supply failure, the Secure Instrument Air (SIA) system SHALL [PS] maintain sufficient pressure in the buffer vessel to allow for at least three valve strokes, based on an initial pressure in the SIA vessel equal to the minimum Instrument Air Header pressure.

Amendment A02

SIA Vessels shall be designed and constructed in accordance with DEP 31.22.00.31-Gen. unless another standard is approved by the Principal.



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The SIA vessel shall be supplied from the Instrument Air Header via a filter. Two non-return valves shall be installed to prevent back flow from the SIA system in the case of loss of Instrument Air Header pressure. The non-return valves shall be of the ball or poppet type and mounted in the vertical line with flow up and marked as Class 1 on the Process Engineering Flow Scheme. Bleeding devices such as regulators shall not be used downstream of the non-return valves. A low pressure alarm shall be provided to indicate low air pressure in the SIA, set at the minimum pressure that is required for three valve strokes.

3.3 INSTRUMENT AIR LINES

Instrument air supply lines downstream of the isolation valve on the main instrument air header and pneumatic signal lines shall be made of stainless steel or equivalent tubing and stainless steel or equivalent compression fittings.

3.4 SOLENOID VALVES

3.4.1 Normally Energised Solenoid Valves

If Normally Energised solenoid valves are used, then the solenoid valve configuration shall be 1oo1 or 2oo2.

3.4.2 Normally De-energised Solenoid Valves

If Normally De-energised solenoid valves are used, then:

1. The solenoid valve configuration SHALL [PS] be 1oo2 i.e. if one solenoid valve fails to energise or fails to open on energisation, the depressuring valve still opens.

2. Line monitoring of the solenoid valve signal lines SHALL [PS] be applied to alarm line discontinuities, short circuits and earth faults. Line monitoring faults shall not result in opening of the high rate emergency depressuring valve.

3. Signal lines for the solenoid valves SHALL [PS] be fireproofed in process areas.

4. The routing of the signal cables shall provide segregation against cause common cause mechanical failures.

3.4.3 Installation requirements

Solenoid valves SHALL [PS] be mounted in the air line between the positioner and the actuator.

Solenoid valves SHALL [PS] be controlled from the Instrumented Protective System. The UPS power back up of the IPS shall be sized for at least 30 minutes, or longer if required by the survivability criteria defined per (2.1).The voltage drop across the signal cable shall be verified during the design to confirm that the voltage at the solenoid meets the manufacturers specification. If Normally De-energised solenoid valves are used, then the actual voltage at the solenoid valve in energised condition SHALL [PS] be measured during the validation step in the commissioning phase.

The exhaust port of the solenoid valve shall be provided with port protectors such as bug screens. These shall be designed such that they do not freeze up during rapid depressurisation of the actuator.

Solenoid valves shall be provided with resilient disc/seat material giving a tight shutoff feature.

3.5 FIRE PROOFING

Fire proofing SHALL [PS] be in accordance with DEP 80.80.00.11-Gen., section 12 for offshore installations and DEP 80.47.10.30-Gen., section 3.3.4, 3.3.8 and 3.3.9 for onshore installations. Fireproofing of cables shall meet the requirements of IEC 60331-21, i.e. able to withstand temperatures of at least 750 C (1382F) for a period of time necessary to complete the actions of the critical function, up to a maximum of 90 minutes. For



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requirements of fire safe valve bodies, see DEP 31.38.01.11-Gen., section 8.8. Fire proof valve seals are not required.

3.6 TEST FACILITIES

Depressuring valves and their accessories shall be easily accessible for testing. Block valves on the upstream and downstream side should be provided. The block valves SHALL [PS] be locked open. Gate valves shall be installed with the stem in the horizontal position.

3.7 HANDSHAKE FOR CRITICAL INFORMATION TO OTHER PROCESSES

The following safety requirements SHALL [PS] be listed and transferred to their respective risk management or engineering processes:

Electrical Engineering: minimum UPS power back up time (3.4.3); Process Safety Engineering: valve capacity (Cv factor) and characteristic (3.1); Process Engineering and Mechanical Engineering: identifier, description and

Class 1 requirement of non-return valves for SIA systems (3.2.2); Alarm Management: identifier and description of solenoid valve line monitoring

alarm (3.4.2) and low pressure alarm of SIA system (3.2.2).

3.8 VALIDATION

Before commissioning into service, it SHALL [PS] be confirmed through examination and testing that the requirements of this DEP are met.



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4. REFERENCES

In this DEP, reference is made to the following publications: NOTES: 1. Unless specifically designated by date, the latest edition of each publication shall be used,

together with any amendments/supplements/revisions thereto.

2. The DEPs and most referenced external standards are available to Shell staff on the SWW (Shell Wide Web) at http://sww.shell.com/standards/.

SHELL STANDARDS

Amendment A02

DEP feedback form DEP 00.00.05.80-Gen.

Noise control (amendments/supplements to ISO 15664) DEP 31.10.00.31-Gen.

Amendment A02

Unfired pressure vessels DEP 31.22.00.31-Gen.

Piping General requirements DEP 31.38.01.11-Gen.

Quarter-turn on/off actuators DEP 31.40.70.30-Gen.

Instruments for measurement and control DEP 32.31.00.32-Gen.

Control valves Selection, sizing and specification DEP 32.36.01.17-Gen.

Classification and implementation of instrumented protective functions

DEP 32.80.10.10-Gen.

Emergency depressuring and sectionalizing DEP 80.45.10.12-Gen.

Assessment of the fire safety of onshore installations DEP 80.47.10.30-Gen

Control and mitigation of fires and explosions on offshore production installations (amendments/supplements to ISO 13702:1999)

DEP 80.80.00.11-Gen.

INTERNATIONAL STANDARDS

Tests for electric cables under fire conditions Circuit Integrity Part 21: Procedures and requirements Cables of rated voltage up to and including 0,6/1,0 kV

IEC 60331-21

Industrial process control valves: Part 2-3: Flow capacity Test procedures Part 4: Inspection and routine testing

IEC 60534-2-3 IEC 60534-4

Issued by: Central Office of the IEC 3, Rue de Varemb CH 1211 Geneva 20 Switzerland Copies can also be obtained from national standards organizations.


1. INTRODUCTION1.1 SCOPE 1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS1.3 DEFINITIONS1.4 CROSS-REFERENCES1.5 SUMMARY OF MAIN CHANGES1.6 COMMENTS ON THIS DEP1.7 DUAL UNITS

2. DEPRESSURING SYSTEMS2.1. GENERAL2.2. HIGH-RATE EMERGENCY DEPRESSURING2.3 LOW-RATE OPERATIONAL DEPRESSURING2.4 HIERARCHY OF OPERATION 2.5 REQUIREMENTS FOR HUMAN-MACHINE INTERFACE

3. SPECIFIC DESIGN AND CONSTRUCTION REQUIREMENTS3.1 DEPRESSURING VALVES 3.2 SECURE INSTRUMENT AIR SYSTEM3.3 INSTRUMENT AIR LINES3.4 SOLENOID VALVES3.5 FIRE PROOFING3.6 TEST FACILITIES3.7 HANDSHAKE FOR CRITICAL INFORMATION TO OTHER PROCESSES3.8 VALIDATION

4. REFERENCES

32451010_Spec_2011-02_A02.pdf

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