1、Cryogenic vessels Couplings for cryogenic service The European Standard EN 13371:2001 has the status ofa British Standard ICs 23.020.40 BS EN 13 3 7 1 :2002 A present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informe
2、d; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on request to its secretary. Cr oss-r e fer enc e s The British Standards which implement international or European publications referred
3、to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contr
4、act. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 9 and a back cover
5、. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 5 March 2002 ISBN0 580 39213 9 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13371 December 2001 ICs 23.020.40; 23.040.70 English version Cryogenic vessels - Couplings for cryogenic service
6、Rcipients cryogniques - Raccords pour service cryognique Kryo-Behlter - Kupplungen fr den tiefkalten Betrieb This European Standard was approved by CEN on 11 November 2001 CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European
7、 Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, Fren
8、ch, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denma
9、rk, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Management Centre: rue de Stassart, 36 B-1050
10、Brussels O 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13371:2001 E EN 13371 :2001 (E) Contents page Foreword 3 1 2 3 4 4.1 4.2 5 5.1 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.3 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 6 7 Scope 4 Normative refe
11、rences 4 Terms and definitions 4 General requirements 5 Design and construction . 5 Materials 5 Prototype tests . 6 General 6 Inspection . 6 Design verification . 6 Dimension of the coupling 6 Identification of material . 6 Clean li ness check 6 Testing 6 General 6 Pressure test 6 Leak tests 6 Stren
12、gth test . 7 Functional test 7 Cleaning and packaging 7 Marking . 7 Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other provisions of EU directives . 8 Bibliography 9 2 EN 13371 :2001 (E) Foreword This European Standard has been prepared by Technical C
13、ommittee 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 the latest by June 2002, and conflicting national standards shall be withdrawn
14、 at the latest June 2002. This European Standard 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 annex ZA, which is an int
15、egral part of this standard. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembou
16、rg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 3 EN 13371 :2001 (E) 1 Scope This European Standard specifies the minimum requirements for the design, manufacture and testing of couplings for cryogenic service to be used for temporary connecting of flexible hose
17、s to cryogenic vessels at the following operating conditions : - design temperature range from - 270 O C to + 65 O C ; - maximum nominal pressure : 80 bar ; - nominal size (DN) from 10 to 100. Permanent connections such as flanges and unions are not covered by this standard. It is intended that the
18、couplings should be designed, tested and marked for service at one of the generally accepted pressure e.g. PN 40. Couplings can then be selected with a PN equal to or greater than the maximum allowable pressure (PS) of the equipment for which they are to be used. 2 Normative references This European
19、 Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications app
20、ly to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 1252-1, Cryogenic Vessels - Materials - Part I: Toughness requirements for temperatures below - 80 “C EN 125
21、2-2, Cryogenic Vessels - Materials - Part 2: Toughness requirements for temperatures between - 10 “C to - 80 “C EN 1333:1996, Pipework components - Definition and selection of PN EN 1797-1, Cryogenic vessels - Gas/materials compatibility EN 12300, Cryogenic vessels - Cleanliness EN IS0 6708:1995, Pi
22、pework components - Definition and selection of DN (nominal size) (IS0 6708:1995) 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply. 3.1 nominal size (DN) as defined in EN IS0 6708:1995 3.2 nominal pressure (PN) as defined in EN 1333:1996 N
23、OTE 1 PN 2 PS (as defined in PED) NOTE 2 See also the last sentence of the scope. 3.3 design temperature range highest and lowest temperature to which the coupling is specified 4 EN 13371 :2001 (E) 3.4 specified minimum temperature specified minimum temperature is the lowest temperature for which th
24、e coupling may be specified 4 General requirements 4.1 Design and construction Couplings shall be able to be connected and disconnected within the full design temperature range. The method of assembling and necessary force shall be specified. The coupling shall be so designed that the necessary forc
25、e to connect or disconnect it may be applied by hand tools in a controlled manner. The design shall be such that disconnection under pressure will be obvious by audible gas venting or other method before complete disconnection. The design shall be sufficient robust to withstand worst anticipated han
26、dling e.g. drop on pavement and the hammering etc. The burst pressure shall be more than three times the nominal pressure within the design temperature range (see 5.3.4). Couplings shall be leak tight in accordance with 5.3.3. Couplings shall be made in such a way that anticipated vibrations from ve
27、hicle engine, pump or pulsating flow may not cause leakage. Couplings for flammable fluids shall be electrically conductive from one end to the other (electrical resistance less than 0,5 Cl) Couplings should have adequate protections, such as a cap or a plug, for mating surfaces and the thread again
28、st damage or contamination. The design of any cap or plug should take in consideration the possibility of leakage of residua I product. If seals are used they should be designed for long life or easy replacement and an instruction for maintenance shall be given. 4.2 Materials All couplings shall be
29、made of materials compatible with materials of the vessel piping equipment, the flexible hoses and the fluid conveyed. A material is said to be compatible when it does not lead to any violent reaction (ignition) or any slow reaction (detrimatal ageing) that may occur during expected life. If the spe
30、cified minimum temperature is equal to or below the boiling point of air or the coupling is intended for oxygen service the material shall be oxygen compatible in accordance with EN 1797-1. A metallic materials which exhibit a ductile/brittle transition shall have minimum impact values in accordance
31、 with EN 1252-1 and EN 1252-2. Metallic materials which can be shown to have no ductile/brittle transition do not require additional impact test. Non metallic materials are so far well established only for use as sealing materials. If such materials are to be used for structural parts they shall at
32、least have properties in accordance with the requirements above. The above requirement need not to be applied on protection caps and plugs. The coupling materials and soldering alloy shall contain less than 70 % copper, if it is specified for mixtures containing acetylene. Materials shall be resista
33、nt to normal atmospheric corrosion and induced stress corrosion. 5 EN 13371 :2001 (E) Materials shall be robust enough to withstand standardized testing conditions in accordance with 5.3. 5 Prototype tests 5.1 General Three sample couplings shall be tested. They shall be representative of the coupli
34、ngs to be produced. The test results shall be recorded in a written report as a reference. 5.2 Inspection 5.2.1 Design verification The coupling shall be inspected to ensure that it satisfies the requirement of clause 4. 5.2.2 Dimension of the coupling Dimensions shall be confirmed to be in accordan
35、ce with the drawings. 5.2.3 Identification of material Certification of all materials together with any weld procedures and welders qualification shall be recorded. 5.2.4 Cleanliness check It shall be checked that the coupling meets the requirement of EN 12300. 5.3 Testing 5.3.1 General Couplings sh
36、all be assembled in accordance with the operating instruction. 5.3.2 Pressure test The assembled coupling shall be subjected to a hydraulic pressure test, at ambient temperature (20 f IO) OC, equal to 1,5 times the nominal pressure. The pressure shall be held for a minimum of 3 min. There shall be n
37、o visual leaks and no visual deformation. As an alternative to the hydraulic test it is also permissible to perform a pneumatic test, at the same pressure, provided that the necessary safety precautions are met. 5.3.3 Leak tests The assembled couplings shall be leak tested at ambient and cryogenic t
38、emperatures and both at PN and at 0,5 bar. The leak test at ambient temperature may be by immersion in water. The test at cryogenic temperature may be by immersion in a cryogenic fluid but other methods of equivalent or better accuracy are permitted. The test gas for the ambient test temperature sho
39、uld be N2 or air and for the cryogenic test He. Couplings with a specified minimum temperature not lower than - 196 “C shall be tested at a temperature not greater than the specified minimum temperature. Couplings with a design temperature lower than - 196 “C shall be tested at a temperature not gre
40、ater than - 196 “C. A deviation in the temperature measured of +/- 10 % (in OC) is allowed depending on the practical conditions of testing. Ambient temperature shall not exceed 25 “C and the humidity shall be not less than 40 %. The leak test shall not be started until the coupling has reached its
41、stable test temperature. A re-tightening of the coupling when cold shall be permitted in accordance with the operating instructions. 6 EN 13371 :2001 (E) The couplin9 leakage rate for non flammable fluids for the warm or cold test shall be less than 1 mbar I/s x DN (1000 Nmm /s x DN) and for flammab
42、le fluids lO-mbar I/s x DN (IO Nmm3/s x DN). 5.3.4 Strength test The assembled couplings shall be hydraulically tested at ambient conditions at a pressure of 3 times PN. Leakage shall be accepted but no bursting. 5.3.5 Functional test The coupling shall be assembled and tightened in accordance with
43、the relevant operating instructions. It shall then be disconnected. Each of these operations shall be repeated until 500 cycles have been completed. Thereafter each of the components of the coupling, excluding seals, shall be visually inspected. Gross deformation, gross wear or cracking shall be cau
44、se for rejection. If the results of the visual examination are ambiguous this can be supplemented by a liquid penetrate test. 6 Cleaning and packaging Couplings shall satisfy the requirements of EN 12300. 7 Marking The couplings shall be permanently marked with the nominal pressure (PN), fluid or fl
45、uid group the specified minimum temperature and EN-number of this standard. 7 EN 13371 :2001 (E) Harmonized clauses/sub-clauses of this standard 4.1 Annex ZA (informative) Content PED Provisions to ensure safe handling and operation Annex I 2.3 Clauses of this European Standard addressing essential
46、requirements or other provisions of EU directives 5 This European standard 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 Pressure Equipment Directive 97/23/EC (PED). Proof test Annex I 3.2.2
47、 WARNING: Other requirements and other EU Directives may be applicable to the product(s) falling within the scope of this standard. The clauses of this standard given in table ZA.l are likely to support requirements of Directive 97/23/EC. Table ZA.l - Comparison between this European standard and PE
48、D I 4.1 I Provisions for filling and discharge I Annex I 2.2.3 b I Compliance with the clauses of this standard provides one with means of conforming with the specific essential requirements of the Directive concerned and associated EFTA regulations. 8 EN 13371 :2001 (E) Bibliography EN 12434:2000,
49、Cryogenic vessels - Cryogenic flexible hoses. 9 BS EN 13 3 7 1 :2002 BSI 389 Chiswick High Road Lon don w4 4AL BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Re vi si ons British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful
