ES-420_PSV

ENGINEERING STANDARD

Title: SAFETY AND RELIEF VALVES Standard No. : 420 Page : 1 of 13 Issue Date : April, 2006

Approvals: Sponsor Director, Control Systems & Electrical Engineering

Director, Specialty Engineering

Name J. Pittman M. A. Tibbitts M. R. Hoffman

Signature ON FILE ON FILE ON FILE

Date 05/04/06 05/05/06 06/02/06

TABLE OF CONTENTS

Page 1.0 SCOPE................................................................................................................................... 2 2.0 CODES, STANDARDS AND REFERENCES .................................................................. 2 3.0 PSV CALCULATIONS AND SIZING BASIS .................................................................. 3 4.0 PSV SELECTION, MATERIALS AND CONSTRUCTION ........................................... 4 5.0 SETTING RANGES............................................................................................................. 4 6.0 BLOWDOWN....................................................................................................................... 5 7.0 TIGHTNESS ......................................................................................................................... 5 8.0 IDENTIFICATION.............................................................................................................. 6 9.0 TESTING AND INSPECTION........................................................................................... 6 10.0 SHIPMENT........................................................................................................................... 6 11.0 INSTALLATION ................................................................................................................. 7 12.0 ACUTELY TOXIC SERVICE APPLICATIONS ............................................................ 7 EXHIBIT 1 - SSR Requirements and Form .......................................................................................... 9 RECORD OF REVISIONS................................................................................................................... 13

Standard No: 420 SAFETY AND RELIEF VALVES

Issue Date: April, 2006

Page 2 of 13

1.0 SCOPE 1.1 This Standard, in conjunction with the Vendor Preference List and specification for the

specific project, shall define the minimum Lyondell requirements for frequently used safety and relief valves.

1.2 Relief System Manual shall be used as an Engineering Guideline in conjunction with this

Standard. 1.3 Where approvals are indicated in this Standard, this refers to Lyondell or its designated

representative. 1.4 Any discrepancy between this Standard and other contract or procurement documents or

specifications, unless specifically indicated as an exception, shall be submitted by the Contractor/Manufacturer/Supplier to the Buyer for a written ruling.

1.5 All measurements are expressed in the U.S. Conventional System of Measurement, followed

by, in parenthesis, the equivalent SI units (metric). All SI units are for reference only and shall not be interpreted as a precise conversion.

1.6 Any proposed deviation from this Standard shall be submitted in writing to Lyondell for

review and approval. It is the responsibility of the individual(s) who request a deviation to submit a request form in a timely manner and in accordance with Lyondell Procedure SEP 107B, Preparation of Addenda to and Deviations from Lyondell Engineering Standards.

2.0 CODES, STANDARDS AND REFERENCES The latest editions of the following Codes and Standards in effect on the date of contract

award shall be used, except as otherwise specified. 2.1 Lyondell Engineering Standards and Guidelines ES 320 Piping EG 4012 Relief System Manual 2.2 Corporate Management System Procedures TEC-03-P1 Process Hazards Analysis and Risk Assessment TEC-03-P4 Relief Valve Availability for Risk Assessment 2.3 American Petroleum Institute (API) API RP 520, Parts 1 & 2 Recommended Practice for the Design and Installation of

Pressure-Relieving Systems in Refineries API RP 521 Guide for Pressure Relief and Depressurizing Systems API 527 Commercial Seat Tightness of Safety Relief Valves with Metal-

to-Metal Seats API 2000 Venting Atmospheric and Low-Pressure Storage Tank 2.4 American Society of Mechanical Engineers (ASME)



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ASME Code Section I Power Boilers ASME Code Section VIII Pressure Vessels 3.0 PSV CALCULATIONS AND SIZING BASIS NOTE: RELIEF DEVICE DOCUMENTATION REQUIREMENTS ARE NOT TO BE

AMENDED OR REDUCED BY PLANT OR PROJECT ADDENDA. 3.1 The basic format requirement for this documentation is that all calculations and analyses shall

be clear, legible, and presented in a manner that an engineer, who is not intimately familiar with the system, will be able to follow. The documentation shall contain a sufficient narrative to allow a viewer understanding of the basic assumptions and reasoning for determining the relief loads. Both quantitative and qualitative analyses shall be included. The sources of all data shall be identified.

Documentation shall show all calculations and the basis of calculations for all plant safety

valves. These documents shall bear the approval signature of the assigned Lyondell process engineer. As a minimum, the documentation shall include the following:

3.1.1 A sketch of the pressure relief device and the system in which it is installed. The sketch shall

show all the equipment protected by the pressure relief device. 3.1.2 A copy of the calculations for the relief load analysis and sizing. 3.1.3 A copy of the computations for the pressure relief device specification and sizing. 3.1.4 A sketch of the pressure relief devices installation, showing all details required for a proper

installation. 3.1.5 A copy of the pressure loss calculations for sizing the pressure relief devices inlet and outlet

piping and the calculations associated with piping supports. 3.1.6 Copies of all drawings, performance curves, equipment data sheets, etc., which were used in

the evaluation of the system. All relief cases shall be summarized on a data sheet as found in the Relief System Manual.

This form provides a summary of the equipment being protected, its design conditions, and the relief cases that were considered in developing the sizing case. Quantitative values of flows, operating conditions, and fluid physical properties for each relief case shall be provided. This form also provides space to list the required pressure relief device areas for each case and to summarize the devices selected for the service.

3.1.7 A completed Instrument Society of America (ISA) data sheet or equivalent. 3.2 All spring loaded and pilot operated safety and relief valves shall be of the manufacturers

current standard type. Materials and design shall conform to the latest revisions of the applicable section of the ASME Code and all local, applicable regulations.



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3.3 The proper ASME Code stamp shall appear on all valves used to protect pressure vessels:

(UV) or (V), as required by the Code. 4.0 PSV SELECTION, MATERIALS AND CONSTRUCTION 4.1 The use of direct spring operated pressure relief valves is strongly recommended. Pilot

operated pressure relief valves should be utilized only when a direct operated pressure relief will not meet the application requirements. Where pilot operated pressure relief valves are used Lyondell EG 4012 shall be reviewed for guidance in the specification and application of the valve.

4.2 In general, relief valves shall have cast carbon steel bodies with stainless steel nozzle, disc,

guide, spindle, and bellows (when required). Spring material shall be compatible with the fluid temperature. Alloy steel bodies or trim that is other than stainless steel shall be used when required by operating conditions or ES 320.

4.3 For pressure vessels, valves that are 1 in. and larger shall be a type having a nozzle bushing

that extends through and beyond the base of the inlet bolting flange and forms the gasket-bearing surface for the inlet flange.

4.4 Inlet and outlet flange ratings are specified to cover the temperature and pressure

requirements. In general, they will agree with the piping specification. Screwed valves may have screwed bonnets and be used where small orifice areas are required, such as thermo relief valves. Screwed valves shall be the modified nozzle type.

4.5 Safety and relief valves shall be furnished with top guide and disc or disc holder, flat seats

and discs, and optically ground seating surfaces. 4.6 For hard-to-hold fluids, an O-ring type or other soft seated type valve may be used with

Lyondells approval. Temperature and corrosion shall be checked as limiting factors. 4.7 All safety and relief valves shall meet or exceed ES 320 for materials and piping joints. 4.8 All safety and relief valves in the process service shall be flanged. 4.9 Screw-type valves are permitted in utility services, such as water, air, and inert gas service,

within the ANSI temperature-pressure rating for the class of 150 lb flanges. 4.10 To ensure chemical compatibility, all valve internal gasket types must be specified on the

instrument specification sheet for bellows style relief valves. Metal gaskets should meet or exceed the metallurgy requirements of the valve. Non-metal gaskets (such as the bellows gasket) material should be derived from the valve outlet piping specification gasket requirements. Flexible graphite should be specified for piping specifications that require flexible graphite or graphite filled spiral wound gaskets. Filled PTFE needs to be specified for piping specifications that require filled PTFE sheet or PTFE filled spiral wound gaskets.

The vendor supplying relief devices to Lyondell must meet the requirements outlined in the

Lyondell relief device specification sheets. 5.0 SETTING RANGES



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5.1 Safety and relief valves shall have the springs supplied and adjusted for the initial set

pressure, as specified in the data sheets. 5.2 Relief valve springs shall be selected so that an adjusted range of 10% of the original set

pressure is possible on the valves whose settings are 250 psig (1.72 MPa), maximum. 5.3 Relief valves set higher than 250 psig (1.72 MPa) shall have a range adjustment of 5% of

the set pressure. 5.4 Set pressure tolerances shall be in accordance with ASMEs Unfired Pressure Vessel Code,

as follows: 5.4.1 Set pressures at 70 psig (.48 MPa) or less2 psi 5.4.2 Set pressures above 70 psig (.48 MPa)3% 5.5 If multiple relief valves are used (instead of one), set pressures are to be staggered to prevent

valve chattering. 5.6 Percent accumulation, used in calculating the sizes of relieving devices, shall be as follows,

unless specified otherwise in the Project Design Basis: Percent Service 3 Steam service where the ASME Boiler Code applies 10 Gas or vapor service and liquids 21 Fire exposure on unfired pressure vessels 5.7 Bellows-type valves, when specified, shall have the bellows rated for the set pressure plus

accumulation. 6.0 BLOWDOWN 6.1 Blowdown (the difference between set pressure and reseating pressure) for all vapor relief

valves, other than those covered by the ASME Code, Section I, shall be that which is normally provided by the vendor. If a different blowdown is required, it shall be reviewed with Lyondell.

6.2 For power boilers, blowdown shall be in accordance with the ASME Code, Section I,

paragraph PG 72. 7.0 TIGHTNESS 7.1 Vendors tightness, when specified, shall meet the tightness test as set forth in API 527. For

pressures greater than 1,000 psi (6.9 MPa), review with Lyondell. 7.2 Absolute bubble tightness, when specified, shall require that the valve be absolutely bubble-

tight at 95% set pressure. Special lapping costs to secure the above shall be stated by the vendor in the proposal when specified in the data sheets.



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8.0 IDENTIFICATION 8.1 Each valve shall be furnished with a stainless steel nameplate that is permanently fastened

with stainless steel screws or rivets, engraved or metal-stamped in accordance with the ASME Code, Section VIII, Division I, paragraph UG 129. Additional markings may be required to include the bench set (cold set) pressure.

8.2 When a temperature correction factor is used to compensate test stand conditions, the cold set

pressure (even if it is equal to the set pressure, the operating relief pressure, and the operating temperature) shall be stamped on the nameplate, or on a separate stainless steel tag that is permanently fastened to the valve in the same manner as the nameplate.

9.0 TESTING AND INSPECTION 9.1 Inspecting, testing, and setting of all relief valves shall be performed by the manufacturer in

the shop prior to shipment. 9.2 Records of the final, approved settings and testing shall be forwarded to Lyondell when

inspection, per paragraph 9.1, is completed. 9.3 Prior to installation, all safety and relief valves shall be tested in a shop designated and

approved by Lyondell. This is a safety practice that takes into account the possibility of a pressure set point error at the factory or a deviation from the pressure setting or seat leakage, due to the transit rigor encountered by the valves on their way from the factory to their point of use.

9.4 The local shop shall tag or stamp all new safety and relief valves with the valve number,

vessel number, set pressure, cold differential test pressure and, when required, the date the device was installed. A companion tag shall be attached to the flange on which the device is mounted, which shall have the valve number, vessel number, and set pressure. These tags shall be in addition to the vendors tag or nameplate.

9.5 Lyondell shall maintain, at the plant and/or field office where the pressure-relieving device is

located, a permanent and progressive record showing the serial or identification number, the location, the pressure setting, spring size, the date of installation in service, and the dates of testing.

9.6 Exhibit 1 contains Lyondells Supplier Surveillance Requirements. These requirements

identify the minimum attributes to be addressed during surveillance of the Supplier by Lyondell or Lyondells designated representative when such surveillance is performed.

10.0 SHIPMENT 10.1 Machined or threaded surfaces that will be exposed to the atmosphere in shipment or storage

shall be coated with an easily removable rust preventative. 10.2 Flanged faces shall be protected by covers that are securely fastened to the flanges. Openings

shall be covered to prevent dirt from entering the valve interior.



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10.3 Ends of the threaded valves shall have threaded protectors, which will exclude dirt. 10.4 Color coding of the valves, when required by Lyondell, shall be in accordance with the

detailed valve specification sheet. 11.0 INSTALLATION 11.1 Installation shall conform to the latest revision of the applicable section of the ASME Code

and the applicable division of Industrial Safety, State Safety, and other local safety codes. 11.2 API RP 520 and API RP 521 shall be used as guides in designing and installing pressure-

relieving systems. 11.3 The use of balanced bellows-type valves shall be considered under the following conditions: 11.3.1 Variable back pressure 11.3.2 Corrosive or viscous fluids on the downstream side 11.3.3 Where there is any possibility of contamination 11.4 Installation of rupture discs, safety heads, or relief valve isolators shall be in accordance with

the ASME Code, Section VIII, Division I, paragraph UG 127, UG 133, UG 134, and the manufacturers installation instructions.

11.5 Where rupture discs, safety heads, or relief valve isolators are specified to be installed on the

inlet side of safety or relief valves, an opening (1/4 in. minimum) shall be provided in the outlet flange of the device or in the inlet nozzle bushing of the safety or relief valve. This opening shall be provided for the mandatory installation of a corrosion-resistant vent, excess flow valve, and pressure gauge. All connections and material shall be in accordance with the applicable pipe specification.

11.6 Where rupture discs, safety heads, or relief valve isolators are specified to be installed on the

outlet side of safety or relief valves, an opening (1/2 in. minimum) shall be provided in the inlet flange of the device for venting to a closed system. Relief valves in this service shall normally be balanced bellows type valves.

11.7 For venting atmospheric and low-pressure storage tanks, API 2000, latest edition, shall be

used as a guide. 11.8 Safety of personnel shall be considered in locating atmospheric discharge stacks; as a

minimum requirement, the discharge stacks shall extend to 10 ft (3 m) above the highest operating platform within a 25 ft (7.6 m) radius.

11.9 Where discharge stacks are vented vertically to the atmosphere, a drain hole shall be provided

in the bottom of the stack. 12.0 ACUTELY TOXIC SERVICE APPLICATIONS



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12.1 Relief valves utilized in Acutely Toxic material service, as defined in ES 320, shall be

balanced bellows type with the valve outlet piped to a closed vent system and subsequent safe location such as a scrubber or flare system. These safety relief vales shall be provided with a rupture disc installed on the inlet side of the relief valve. A mandatory telltale assembly consisting of an opening (1/4 in. minimum) located in the outlet flange of the disc device holder or in the inlet nozzle bushing of the relief valve, an excess flow check valve, and pressure switch or transmitter shall be installed. The outlet side of the excess flow valve shall be piped back to the relief valve discharge piping vent header. The output of the pressure switch or transmitter shall be alarmed in the control room to notify operators that the rupture disk has failed or the rupture disk/relief valve has opened.

These acutely toxic service rupture disk/pressure relieve valve systems shall be installed as

redundant pairs with the proper isolation valves to allow on-line maintenance of the system. Where failed or leaking rupture disk are detected they shall be replaced immediately.



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EXHIBIT 1

INSTRUCTIONS FOR USE OF SUPPLIER SURVEILLANCE REQUIREMENTS

1.0 PURPOSE The Supplier Surveillance Requirements (SSR) represent Lyondells minimum requirements

for monitoring the Supplier during fabrication of equipment. The SSR does not modify or supersede the technical requirements specified for the equipment

contained in the main body of the Lyondell Standard. The Lyondell Standard specifies the minimum requirements to be met by the Supplier for fabrication, inspection, testing, documentation, preparation for shipment, etc.

2.0 SCOPE The SSRs apply to the surveillance of shop fabrication of Category I and II, Equipment;

Class 1, 2, and 3, Packaged Equipment. These categories and classes are defined by the references listed in Paragraph 4.0 of this attachment. The extent that these requirements are applied to Category III and IV equipment; Class 4, 5, and 6, Packaged Equipment, shall be determined by the Responsible Engineer on a case by case basis using engineering judgment.

3.0 DEFINITIONS Hold Point: An activity requiring release from Lyondell or Lyondells representative before

the Supplier may proceed in performing the activity. Quality Surveillance Representative (QSR): An individual representing Lyondell who is

assigned to perform surveillance of the Supplier. Responsible Engineer: Lyondell Engineer assigned to the project who is responsible for the

engineering phase of the equipment. Review Documentation: Review of procedures, records, and other specified documents to

determine compliance with the referenced Standard(s). Supplier: The organization fabricating/manufacturing the equipment. Verify by Inspection: Visual Inspection to: (a) verify document approval status, (b) check

fabrication for conformance to requirements. Witness Point: An activity that may be observed by Lyondell or its representative. Unless

otherwise specified, the supplier is required to notify Lyondell or its representative at least five days prior to activity performance.

4.0 REFERENCES 4.1 Lyondell Quality Assurance Standard 551 (Criticality Rating Requirements for Engineered

and Packaged Equipment)



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4.2 Lyondell Procedure CPP 601 (Packaged Equipment) 5.0 INSTRUCTIONS 5.1 The SSR contains attributes (denoted with an X) which must be verified, as a minimum,

when surveillance of the Suppliers shop fabrication activities is required. Where an X is not shown for a given attribute on the existing SSR, the attribute must be reviewed by the Responsible Engineer. The Responsible Engineer must either specify a surveillance function (as denoted with an X) in the Function column of the SSR or identify the attribute as not applicable (N/A) in the Supplemental Information column of the SSR.

5.2 Additional requirements may be added by the Responsible Engineer, when appropriate, based

on the engineering issues related to the specific equipment being fabricated. The additional requirements shall be identified with an (*) in No. column to distinguish these types of requirements from Lyondells minimum requirements.

5.3 The surveillance requirements indicated on the SSR for Suppliers of Category III and IV

Equipment; Class 4, 5, and 6 Packaged Equipment, may be modified by the Responsible Engineer based on engineering judgment. (This does not imply any modification of the technical requirements contained in the main body of the Lyondell Standard, only the intensity of surveillance over the Suppliers activities).

LYONDELL SUPPLIER SURVEILLANCE REQUIREMENTS Date: Rev:

SSR No. 420 Item: Safety & Relief Valves Page 11 of 13

Lyondell Approval:

Prepared by:

Equipment Description: Critical Equip. Category:

Supplier/Contractor: Specifications/Codes/Standards: Lyondell ES 420 API 520

Surveillance Functions: 1 - Verify by Inspection 2 - Witness Point 3 - Hold Point 4 - Review Documentation

Lyondell P.O./Contract:

Function No. Attribute 1 2 3 4 Supplemental Information

1 Pre-Fab Meeting

2 Drawings & Calculations Approved by Lyondell.

3 Verify Data Sheet Approved by Lyondell.

4 Verify Materials of Construction

5 Verify Latest DWG's/Calc's/Data Sheet/Spec

6 Verify Size/Rating/Capacity

Dimensional

Component Parts (See Note 1)

7

Outline

Visual Inspection

Component Parts

8

Assembled Unit

9 Test Gauge Calibration

10 Verify Test Stand Setup

11 Testing

12 Verify Correct Tagging

13 Final Documentation Review

14 Prep Shipment

15 Release for Shipment

16

17

18

19

20

21

22

SSR No. 420 Item: Safety & Relief Valves Page 12 of 13

Lyondell Approval:

Prepared by:

Equipment Description: Critical Equip. Category:

Supplier/Contractor: Specifications/Codes/Standards: Lyondell ES 420 API 520

Surveillance Functions: 1 - Verify by Inspection 2 - Witness Point 3 - Hold Point 4 - Review Documentation

Lyondell P.O./Contract:

Function No. Attribute 1 2 3 4 Supplemental Information

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

Remarks:

Legend: (X) Mandatory Surveillance Function performed by QSR.

(*) Attributes specifically added for this Purchase Order. Where (X) is not shown, this function needs to be specified on a case basis



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RECORD OF REVISIONS

(as compared to February, 2000 issue) Updated this Standard to provide requirements for Acutely Toxic materials, requirements for gasket materials and recommendation to use direct spring opposed relief valves. 2.2 Added paragraph and renumbered subsequent paragraphs. 4.0 Renamed section. 4.1 Added new paragraph and renumbered subsequent paragraphs. 4.10 Added new paragraph. 11.5 Revised paragraph for clarity. 11.6 Revised paragraph for clarity. 12.0 Added new section.

TABLE OF CONTENTS1.0 SCOPE2.0 CODES, STANDARDS AND REFERENCES3.0 PSV CALCULATIONS AND SIZING BASIS4.0 PSV SELECTION, MATERIALS AND CONSTRUCTION5.0 SETTING RANGES6.0 BLOWDOWN7.0 TIGHTNESS8.0 IDENTIFICATION9.0 TESTING AND INSPECTION10.0 SHIPMENT11.0 INSTALLATION12.0 ACUTELY TOXIC SERVICE APPLICATIONSEXHIBIT 1 - INSTRUCTIONS FOR USE OF SUPPLIER SURVEILLANCE REQUIREMENTSFill in SSR FormRECORD OF REVISIONSWord Version ES 420

ES-420_PSV

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