1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 21013-4:2012Cryogenic vessels Pilotoperated pressure reliefdevicesPart 4: Pressure-relief accessories forcryogenic serviceBS ISO 21013-4:2012 BRITISH STANDARDNational fore
2、wordThis British Standard is the UK implementation of ISO 21013-4:2012.The UK participation in its preparation was entrusted to TechnicalCommittee PVE/18, Cryogenic vessels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purp
3、ort to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 66480 9ICS 23.020.40Compliance with a British Standard cannot confer immunity fromlegal obligations
4、.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2012.Amendments issued since publicationDate Text affectedBS ISO 21013-4:2012 ISO 2012Cryogenic vessels Pilot operated pressure-relief devices Part 4: Pressure-relief accessories for c
5、ryogenic serviceRcipients cryogeniques Dispositifs de scurit pour le service cryognique Partie 4: Dispositifs de scurit pour la pression pilotage automatiqueINTERNATIONAL STANDARDISO21013-4First edition2012-06-01Reference numberISO 21013-4:2012(E)BS ISO 21013-4:2012ISO 21013-4:2012(E)ii ISO 2012 All
6、 rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO a
7、t the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 21013-4:2012ISO 21013-4:2012(E) ISO 2012 All rights reserved ii
8、iContents PageForeword iv1 Scope 12 Normative references . 13 Terms and definitions . 14 Requirements . 34.1 General . 34.2 Design . 34.3 Materials . 45 Qualification and testing . 55.1 Type approval . 55.2 Type approval tests . 65.3 Production testing . 86 Determination of the certified coefficient
9、 of discharge (Kdr). 87 Set pressure tolerances . 88 Re-seating pressure . 89 Cleanliness 810 Marking . 810.1 Marking on the shell body of the main valve . 810.2 Marking on the body of the pilot valve 810.3 Marking on an identification plate 910.4 Additional marking 911 Sealing 9Bibliography .10BS I
10、SO 21013-4:2012ISO 21013-4:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body inte
11、rested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnica
12、l Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the tec
13、hnical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO
14、shall not be held responsible for identifying any or all such patent rights.ISO 21013-4 was prepared by Technical Committee ISO/TC 220, Cryogenic vessels.ISO 21013 consists of the following parts, under the general title Cryogenic vessels Pressure-relief accessories for cryogenic service: Part 1: Re
15、closable pressure-relief valves Part 2: Non-reclosable pressure-relief devices Part 3: Sizing and capacity determination Part 4: Pressure-relief accessories for cryogenic serviceiv ISO 2012 All rights reservedBS ISO 21013-4:2012INTERNATIONAL STANDARD ISO 21013-4:2012(E)Cryogenic vessels Pilot operat
16、ed pressure-relief devices Part 4: Pressure-relief accessories for cryogenic service1 ScopeThis part of ISO 21013 specifies the requirements for the design, manufacture and testing of pilot operated pressure-relief valves for cryogenic service, i.e. for operation with cryogenic fluids in addition to
17、 operation at temperatures from ambient to cryogenic. This part of ISO 21013 is restricted to valves not exceeding a size of DN 300 designed to relieve single phase vapours, gases, or mixtures of gases and/or vapours.This part of ISO 21013 does not provide methods for determining the capacity of rel
18、ief valve(s) for a particular cryogenic vessel. Such methods are provided in ISO 21013-3.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition o
19、f the referenced document (including any amendments) applies.ISO 4126-4:2004, Safety devices for protection against excessive pressure Part 4: Pilot operated safety valvesISO 15761, Steel gate, globe and check valves for sizes DN 100 and smaller, for the petroleum and natural gas industriesISO 21010
20、, Cryogenic vessels Gas/materials compatibilityISO 21028-1, Cryogenic vessels Toughness requirements for materials at cryogenic temperature Part 1: Temperatures below 80 CISO 21028-2, Cryogenic vessels Toughness requirements for materials at cryogenic temperature Part 2: Temperatures between 80 C an
21、d 20 CISO 23208, Cryogenic vessels Cleanliness for cryogenic serviceASME B16.34, Valves flanged, threaded and welding endEN 12516-2:2004, Industrial valves Shell design strength Part 2: Calculation method for steel valve shellsEN 12516-3:2002, Valves Shell design strength Part 3: Experimental method
22、EN 12516-4:2008, Industrial valves Shell design strength Part 4: Calculation method for valve shells manufactured in metallic materials other than steel3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1valvecomplete assembly consisting of the main
23、 valve and its pilot valve ISO 2012 All rights reserved 1BS ISO 21013-4:2012ISO 21013-4:2012(E)3.2DN (nominal size)alphanumeric designation of size for components of a pipework system, which is used for reference purposesNOTE It comprises the letters DN followed by a dimensionless whole number which
24、 is indirectly related to the physical size, in millimetres, of the bore or outside diameter of the end connections. SOURCE: ISO 6708:1995, 2.13.3pressurealgebraic difference between the absolute pressure and the atmospheric pressureNOTE This is also known as gauge pressure.3.4rated minimum temperat
25、urelowest temperature for which the pressure-relief valve is rated by the manufacturer3.5cryogenic fluidrefrigerated liquefied gas which is partially liquid because of its low temperatureNOTE 1 This includes totally evaporated liquids and supercritical fluids.NOTE 2 In the context of this part of IS
26、O 21013, the refrigerated but non-toxic gases and gas mixtures given in Table 1 are referred to as cryogenic fluids.Table 1 Refrigerated but non-toxic gasesClassification CodeIdentification number, name and description a3 AAsphyxiant gases1913 Neon, refrigerated liquid1951 Argon, refrigerated liquid
27、1963 Helium, refrigerated liquid1970 Krypton, refrigerated liquid1977 Nitrogen, refrigerated liquid2187 Carbon dioxide, refrigerated liquid2591 Xenon, refrigerated liquid3136 Trifluoromethane, refrigerated liquid3158 Gas, refrigerated liquid, N.O.S. (not otherwise specified)3 OOxidizing gases1003 Ai
28、r, refrigerated liquid1073 Oxygen, refrigerated liquid2201 Nitrous oxide, refrigerated liquid, oxidizing3311 Gas, refrigerated liquid, oxidizing, N.O.S.2 ISO 2012 All rights reservedBS ISO 21013-4:2012ISO 21013-4:2012(E)Classification CodeIdentification number, name and description a3 FFlammable gas
29、es1038 Ethylene, refrigerated liquid1961 Ethane, refrigerated liquid1966 Hydrogen, refrigerated liquid1972Methane, refrigerated liquid or natural gas, refrigerated liquid with high methane content3138Ethylene, acetylene and propylene mixture, refrigerated liquid, containing at least 71,5 % ethylene
30、with not more than 22,5 % acetylene and not more than 6 % propylene3312 Gas. Refrigerated liquid, flammable, N.O.S.aClassification codes, identification number, name and description according to the United Nations.3.6rated pressurePRmaximum pressure difference between the inside and outside of any p
31、ressure retaining boundary for which it is designed to be operated at 20 CNOTE PR of the valve is the lowest PR of any component of the valve.3.7type 1 valverelief valve which will open below a specified multiple of set pressure (e.g. 1.3 set pressure) with the pilot disabled3.8type 2 valverelief va
32、lve which will not open below a specified multiple of set pressure (e.g. 1.3 set pressure) with the pilot disabled3.9valve category Arelief valve type which passed the test of the repeatability of seat tightness at re-seat of 1 000 cycles3.10valve category Brelief valve type which passed the test of
33、 the repeatability of seat tightness at re-seat of 20 cycles4 Requirements4.1 GeneralThe valve shall satisfy all the requirements of ISO 4126-4 except in the event of conflicting or different requirements, when this part of ISO 21013 shall take precedence over ISO 4126-4.4.2 Design4.2.1 Design tempe
34、ratureThe valve shall be suitable for operation at all temperatures between the rated minimum temperature and + 65 C within the intended pressure range.Table 1 (continued) ISO 2012 All rights reserved 3BS ISO 21013-4:2012ISO 21013-4:2012(E)4.2.2 Disc guidingThe design of guiding shall avoid malfunct
35、ion of the valve due to deposition and freezing of atmospheric moisture on and within the valve during normal operation. The valve shall be sufficiently robust such that the effectiveness of the guiding cannot be defeated by normal handling.4.2.3 InsertsWhere a disc soft insert is used to ensure lea
36、k-tight shut off, the design shall be such as to prevent cold flow of the insert to a degree that results in the valve failing to operate correctly.4.2.4 Sublimating fluids serviceWhere the valve is specified as suitable for service with products that, when vented at valve operating conditions, cond
37、ense from gas or vapour directly to solid, e.g. CO2, the design shall be such as to avoid the valve failing to operate correctly due to deposition of solid product within the valve body or its outlet. In particular, the pilot shall be provided with some means to ensure its safe operation in case of
38、deposition of solids within it.4.2.5 Electric continuityFor valves in flammable fluids service, the maximum electrical resistance shall not exceed 1 000 with no more than 28 volts between the ports in order to ensure electrical continuity to prevent build-up of static electricity.4.2.6 Set pressureS
39、et pressure of the valve shall not exceed its PR.4.2.7 Minimum shell thicknessThe minimum shell thickness shall be as specified in ISO 15761, ASME B16.34 or EN 12516-2, EN 12516-3 or EN 12516-4 as applicable for the pressure rating and size of the valve.4.3 Materials4.3.1 GeneralMaterial shall be in
40、 conformance with an internationally recognized standard and be compatible with the fluid. Galling, frictional heating, and galvanic corrosion shall also be considered in the selection of materials. Materials shall also be oxygen compatible if relevant (see 4.3.5.1).Materials not listed in an intern
41、ationally recognized standard shall be controlled by the manufacturer of the pressure-relief valve by a specification ensuring control of chemical content and physical properties, and quality at least equivalent to an internationally recognized standard. A test certificate providing the chemical con
42、tent and physical property test results shall be provided with the pressure-relief valve.4.3.2 Metallic materialsMetallic materials to be used in the construction of cryogenic valves shall meet the requirements of ISO 21028-1 or ISO 21028-2 as appropriate for the rated minimum temperature.These requ
43、irements apply only to the valve parts exposed to low temperatures in normal service. Metallic materials which do not exhibit ductile/brittle transition, and non-ferrous materials which can be shown to have no ductile/brittle transition, do not require additional impact tests.Forged, rolled, wrought
44、, and fabricated valve components from raw materials from these processes need not be impact tested if the rated minimum temperature is higher than the ductile/brittle transition range temperatures of the material. Castings meeting the requirements of one of the applicable mandatory Appendices I and
45、 IV or II and III for forgings and rolled or wrought material of ASME B16.34 need not be impact tested if the rated minimum temperature is higher than the ductile/brittle transition range temperatures of the material. At least 4 ISO 2012 All rights reservedBS ISO 21013-4:2012ISO 21013-4:2012(E)one r
46、andomly selected valve body (including bonnet, if applicable) material from each production lot casting not meeting the requirements of this subclause shall be impact tested at the rated minimum temperature.4.3.3 Non-metallic materialsNon-metallic materials are well established only for use for inse
47、rts on the disc or seat to provide leak tightness across the seat when the valve is closed. If such materials are to be used for significant structural parts, they shall have the properties appropriate to the application. The ductile/brittle transition temperature of the material shall be below the
48、rated minimum temperature of the valve, so as to have mechanical properties that will allow the valve to pass the type approval test defined in 5.2, be resistant to sunlight, weather and aging, and be compliant with 4.3.5.4.3.4 Corrosion resistanceIn addition to resistance to normal atmospheric corr
49、osion, particular care must be taken to ensure that the valve cannot be rendered inoperative by accumulation of corrosion products. Some copper alloys are susceptible to stress corrosion cracking, consequently careful consideration shall be given before selection of these materials for components under stress.4.3.5 Gas material compatibility4.3.5.1 OxygenIf the rated minimum temperature is equal to or below the boiling point of air or the valve is intended for service with oxygen or o
