1、BS EN 1626:2008ICS 23.020.40;23.060.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDCryogenic vessels Valves for cryogenicserviceThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 28 February2009 BSI 2009ISBN
2、978 0 580 58010 9Amendments/corrigenda issued since publicationDate CommentsBS EN 1626:2008National forewordThis British Standard is the UK implementation of EN 1626:2008. Itsupersedes BS EN 1626:1999 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PVE/
3、18, Cryogenic vessels.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot c
4、onfer immunityfrom legal obligations.BS EN 1626:2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 1626November 2008ICS 23.020.40; 23.060.01 Supersedes EN 1626:1999 English VersionCryogenic vessels - Valves for cryogenic serviceRcipients cryogniques - Robinets pour usagecryogniqueKryo Behlter - A
5、bsperrarmaturen fr tiefkalten BetriebThis European Standard was approved by CEN on 13 September 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-
6、to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder
7、 the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hung
8、ary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: ru
9、e de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1626:2008: EBS EN 1626:2008EN 1626:2008 (E) 2 Contents Foreword . 3 1 Scope 4 2 Normative references 4 3 Terms and definitions . 5 4 Requirements.
10、 5 5 Testing 7 6 Cleanliness . 9 7 Marking . 9 Annex A (informative) Recommended methods for leak tightness testing of cryogenic valves 10 Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EC Directive 97/23/EC (PED) . 12 BS EN 1626:2008EN 1626:2008
11、 (E) 3 Foreword This document (EN 1626:2008) has been prepared by Technical Committee CEN/TC 268 “Cryogenic vessels”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at t
12、he latest by May 2009, and conflicting national standards shall be withdrawn at the latest by May 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all su
13、ch patent rights. This document will supersede EN 1626:1999. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative
14、 Annex ZA, which is an integral part of this document. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, Fran
15、ce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 1626:2008EN 1626:2008 (E) 4 1 Scope This European Standard specifies the requireme
16、nts for the design, manufacture and testing of valves for cryogenic service, i.e. for operation with cryogenic fluids below - 10 C as well as at ambient conditions to allow for start-up and run-down. It specifies additional requirements for cryogenic service for the appropriate valve product standar
17、d. NOTE a cryogenic fluid (refrigerated liquefied gas) is a gas which is partially liquid because of its low temperature (including totally evaporated liquids and supercritical fluids). It applies to sizes up to DN 150 including vacuum jacketed cryogenic valves. This European Standard is not applica
18、ble to safety valves and valves for liquefied natural gas (LNG). It is intended that the valve be designed and tested to satisfy a pressure rating (PN or Class). Valves may then be selected with a PN or Class equal to or greater than the maximum allowable pressure (PS) of the equipment with which it
19、 is to be used. 2 Normative references The 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 of the referenced document (including any amendments) applies. EN 19, Ind
20、ustrial valves - Marking of metallic valves EN 736-1, Valves - Terminology - Part 1: Definition of types of valves EN 736-2, Valves - Terminology - Part 2: Definition of components of valves EN 736-3, Valves - Terminology - Part 3: Definition of terms EN 1092-1, Flanges and their joints - Circular f
21、langes for pipes, valves, fittings and accessories, PN designated - Part 1: Steel flanges EN 1251-1, Cryogenic vessels - Transportable vacuum insulated vessels of not more than 1000 litres volume Part 1: Fundamental requirements EN 1252-1, Cryogenic vessels - Materials - Part 1: Toughness requiremen
22、ts for temperatures below - 80 C EN 1333, Flanges and their joints - Pipework components - Definition and selection of PN EN 1759-1, Flanges and their joint Circular flanges for pipes, valves, fittings and accessories, Class designated Part 1: Steel flanges, NPS to 24 EN 1797, Cryogenic vessels - Ga
23、s/material compatibility EN 12266-1, Industrial valves - Testing of valves - Part 1: Pressure tests, test procedures and acceptance criteria - Mandatory requirements EN 12266-2, Industrial valves - Testing of valves - Part 2: Tests, test procedures and acceptance criteria - Supplementary requirement
24、s EN 12300, Cryogenic vessels - Cleanliness for cryogenic service EN 12516-1, Industrial valves Shell design strength Part 1: Tabulation method for steel valve shells EN 12516-2, Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells EN 12516-4, Industrial valv
25、es Shell design strength Part 4: Calculation method for valve shells manufactured in metallic materials other than steel BS EN 1626:2008EN 1626:2008 (E) 5 EN ISO 6708, Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995) 3 Terms and definitions For the purposes of this
26、 document, the terms and definitions given in EN 736-1, EN 736-2 and EN 736-3, and the following apply. 3.1 nominal size (DN) defined in accordance with EN ISO 6708 3.2 pressure rating either nominal pressure (PN) as defined in accordance with EN 1333 and EN 1092-1 or Class rating as defined in EN 1
27、759-1 3.3 specified minimum temperature lowest temperature the valve is specified for 3.4 valve category A valves intended to be operated with normal frequency (above 20 cycles a year) 3.5 valve category B valves intended to be operated only occasionally i.e. with a frequency below 20 cycles a year
28、4 Requirements 4.1 Materials 4.1.1 Metallic materials Metallic materials to be used in the construction of cryogenic valves shall be suitable for general valve uses as defined in EN 12516-1, EN 12516-2 and EN 12516-4. In addition, the following requirements apply: 4.1.1.1 Toughness requirements Mate
29、rials which exhibit a ductile/brittle transition shall have minimum impact test values specified in EN 1252-1. These requirements apply only to the critical parts of the valve exposed to cryogenic temperatures (and not to control elements for example). Non ferrous materials which can be shown to hav
30、e no ductile/brittle transition do not require additional impact tests. 4.1.1.2 Corrosion resistance Materials shall be resistant to or protected from normal atmospheric corrosion and to the medium handled. 4.1.1.3 Oxygen compatibility If the specified minimum temperature is equal to or below the bo
31、iling point of air (approximately 190 C at atmospheric pressure) or the valve is intended for oxygen service the materials which are, or likely to be, in contact with oxygen or an oxygen enriched air shall be oxygen compatible in accordance with EN 1797. 4.1.1.4 Flammable gas compatibility For hydro
32、gen service, see EN 1797. BS EN 1626:2008EN 1626:2008 (E) 6 Copper alloys less than 70 % of copper shall be used for fluids containing acetylene. 4.1.2 Non metallic materials Non metallic materials to be used in packing, seats and glands shall: - have mechanical properties which will allow the valve
33、s to pass the sample valve test for category A valves as defined in this standard (see 5.2); - be oxygen compatible, if applicable, see 4.1.1.3. If non metallic materials are used for structural parts, their suitability shall be proven. 4.2 Design 4.2.1 General The valves shall fulfil their function
34、 in a safe manner within the temperature range from + 65 C to their specified minimum temperature and the pressure range intended for use. 4.2.2 Packing gland Valves can have an extended stem. The length of the extension shall be sufficient to maintain the stem packing at a temperature high enough t
35、o permit operation within the normal temperature range of the packing material. Valves without an extended stem shall have a stem packing capable of operating at the specified minimum temperature. The handle shall be designed to remain operable for the duration of the sample valve test in accordance
36、 with 5.2.3.2. Gland designs incorporating a gland nut with a male or female thread shall be such that the nut shall not unscrew unintentionally, for example when the valve is operated. 4.2.3 Operating positions Valves with an extended stem shall be capable of operation with the valve stem at any po
37、sition from the vertical to 25 above the horizontal. 4.2.4 Trapped liquid Cavities where liquid can be trapped and build up detrimental pressures due to evaporation or expansion of the liquid during warming up of the valve are not permitted. NOTE For ball and gate valves this requirement can be met
38、by the provision of a pressure relief hole or passage or other means, e.g. pressure relieving seats, to relieve pressure in the bonnet and body cavities to the upstream side of the valve. 4.2.5 Valve bonnet Valve bonnets may be brazed, welded, bolted, screwed or union type. Union type bonnets shall
39、not be used on valves greater than DN 50. Union nuts shall be locked to the body. Screwed bonnets shall also be secured by a union nut or another device offering equivalent safety. 4.2.6 Securing of gland extension For bronze or copper alloy valves of PN 100 or greater, the gland extensions shall be
40、 mechanically secured in the bonnet prior to brazing. (For instance by screwing). BS EN 1626:2008EN 1626:2008 (E) 7 4.2.7 Seat (seating assembly) Valves may have metal/metal or metal/soft or soft/soft seating assembly. Soft seat materials shall be adequately supported to prevent cold flow of the sea
41、t material or shall be backed by a secondary metal seat. 4.2.8 Blow-off safety of the spindle The valve stem/shaft shall be secured so that it cannot be blown out of the body in the event of the gland being removed while the valve is under pressure. 4.2.9 Torque The maximum torque to operate manual
42、valves under service conditions, when applied at the rim of the hand wheel or lever, shall not exceed 350 x R N.m, except for valve seating and unseating, when it shall not exceed 500 x R Nm. For a hand-wheel, R is the radius of the wheel in meters. For a lever R is the length of the lever in meters
43、 minus 0,05 m. The valve shall be robust enough to withstand 1000 R N.m or equivalent in linear force as specified above without damage. A lower value is permitted if there is a limiting torque or stroke device. Stems/shafts torsional strength within the pressure boundary shall be designed to exceed
44、 the torsional strength of the stem/shaft to the packing by at least 10 %. Valves intended for actuator operation may have torque or linear force requirements deviating from the above. The sample valve tests shall then be performed including a proper actuator to operate the valve. 4.2.10 Electrical
45、continuity and explosion proofness All valves shall have a maximum electrical resistance of 1000 in order to ensure electrical continuity to prevent build-up of static electricity. For flammable fluids, any equipment attached to or associated with a valve shall be suitable for the hazard zone. 5 Tes
46、ting 5.1 Production tests The production test shall be performed in accordance with the requirements of applicable valve product standards. If these standards refer to EN 12266-1 and EN 12266-2, closure test leakage rate A is required. 5.2 Type testing 5.2.1 Selection of sample valves One sample val
47、ve shall be tested. It shall be representative of the valves to be produced. If a range of valves of identical design but with different size is to be tested, one sample of the smallest and one sample of the largest shall be tested. 5.2.2 Verification of the design A second sample valve shall be ins
48、pected to ensure that the design satisfies the requirements of Clause 4. 5.2.3 Ambient condition tests 5.2.3.1 Initial tests The sample valve shall first pass the tests as described in 5.1. BS EN 1626:2008EN 1626:2008 (E) 8 5.2.3.2 Strength test The valve in a partially open position shall be hydrau
49、lically tested for at least 1 min with a pressure 4 times PN (or the maximum rated pressure) for valves with a PN lower than PN 100 (or Class lower than Class 600) and 2,25 times for higher pressure ratings. Leakage at joint level shall be accepted but failure by bursting or leakage through the body is unacceptable. Certain components (e.g. membranes or bellow seals) may be temporarily removed or replaced by a dummy during this test. The strength test shall be performed after all other tests or on separate samples. The purpose of this test is to ve
