1、BSI Standards PublicationBS EN ISO 4126-1:2013Safety devices for protectionagainst excessive pressurePart 1: Safety valvesCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN IS
2、O 4126-1:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO4126-1:2013. It supersedes BS EN ISO 4126-1:2004 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PSE/18/6, Industrial valves, steam traps, actuators an
3、dsafety devices against excessive pressure - Safety devices againstexcessive pressure.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its
4、 correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 66503 5ICS 13.240Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strate
5、gy Committee on 31 July 2013.Amendments issued since publicationDate Text affectedCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NOR
6、M EN ISO 4126-1 July 2013 ICS 13.240 Supersedes EN ISO 4126-1:2004English Version Safety devices for protection against excessive pressure - Part 1: Safety valves (ISO 4126-1:2013) Dispositifs de scurit pour protection contre les pressions excessives - Partie 1: Soupapes de sret (ISO 4126-1:2013) Si
7、cherheitseinrichtungen gegen unzulssigen berdruck - Teil 1: Sicherheitsventile (ISO 4126-1:2013) This European Standard was approved by CEN on 28 December 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
8、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 CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, Fr
9、ench, 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 CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgari
10、a, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turke
11、y and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN IS
12、O 4126-1:2013: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 4126-1:2013EN ISO 4126-1:2013 (E) 3 Foreword This document (EN ISO 4126-1:2013) has been prepared by Tec
13、hnical Committee ISO/TC 185 “Safety devices for protection against excessive pressure“ in collaboration with Technical Committee CEN/TC 69 “Industrial valves” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of
14、an identical text or by endorsement, at the latest by January 2014, and conflicting national standards shall be withdrawn at the latest by January 2014. 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
15、be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 4126-1:2004. 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
16、 relationship with EU Directive(s), see informative 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, Croa
17、tia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and t
18、he United Kingdom. Endorsement notice The text of ISO 4126-1:2013 has been approved by CEN as EN ISO 4126-1:2013 without any modification. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from
19、 IHS-,-,-BS EN ISO 4126-1:2013EN ISO 4126-1:2013 (E) 4 Annex ZA (informative) Relationship between this International Standard and the Essential Requirements of EU Directive 97/23/EC (PED) By agreement between ISO and CEN, this CEN annex is included in the DIS and the FDIS but will not appear in the
20、 published ISO standard. This International Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association to provide one means of conforming to Essential Requirements of the New Approach Directive 97/23/EC (PED). Once this standard is cite
21、d in the Official Journal of the European Communities under that Directive and has been implemented as a national standard in at least one Member State, compliance with the normative clauses of this standard given in Table ZA.1 confers, within the limits of the scope of this standard, a presumption
22、of conformity with the corresponding Essential Requirements of that Directive and associated EFTA regulations. Table ZA.1 Correspondence between this International Standard and Directive 97/23/EC (PED) Sub-clauses of this International Standard Essential Requirements of Directive 97/23/EC (PED) Esse
23、ntial Requirements Annex I of PED 5,6,7,8,9 Safety accessories 2.11.1 5.1.5 Safety of operation 2.3 5.1.6 Drain and venting 2.5 6.3 Proof test 3.2.2 10 Marking and labelling 3.3 WARNING: Other requirements and other EU Directives may be applicable to the products falling within the scope of this sta
24、ndard. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 4126-1:2013ISO 4126-1:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative refe
25、rences 13 Terms and definitions . 14 Symbols and units . 45 Design 45.1 General . 45.2 Valve end connections 55.3 Minimum requirements for springs . 55.4 Materials . 66 Production testing 66.1 Purpose 66.2 General . 66.3 Hydrostatic testing 66.4 Pneumatic testing . 76.5 Adjustment of set or cold dif
26、ferential test pressure . 86.6 Seat leakage test. 87 Type testing 87.1 General . 87.2 Tests to determine operating characteristics . 97.3 Tests to determine flow characteristics 117.4 Determination of the coefficient of discharge .127.5 Certification of coefficient of discharge 128 Determination of
27、safety valve performance .139 Sizing of safety valves .1310 Marking and sealing .1310.1 Marking 1310.2 Sealing of a safety valve 13Bibliography .14Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without lice
28、nse from IHS-,-,-BS EN ISO 4126-1:2013ISO 4126-1:2013(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.
29、 Each member body interested 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 Interna
30、tional Electrotechnical 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 Standa
31、rds adopted by the technical 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
32、of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 4126-1 was prepared by Technical Committee ISO/TC 185, Safety devices for protection against excessive pressure.This third edition cancels and replaces the second edition (ISO 4126-1:2004), which ha
33、s been technically revised. It also incorporates the Technical Corrigendum ISO 4126-1:2004/Cor.1:2007.ISO 4126 consists of the following parts, under the general title Safety devices for protection against excessive pressure: Part 1: Safety valves Part 2: Bursting disc safety devices Part 3: Safety
34、valves and bursting disc safety devices in combination Part 4: Pilot operated safety valves Part 5: Controlled safety pressure relief systems (CSPRS) Part 6: Application, selection and installation of bursting disc safety devices Part 7: Common data Part 9: Application and installation of safety dev
35、ices excluding stand-alone bursting disc safety devices Part 10: Sizing of safety valves for gas/liquid two-phase flow Part 11: Performance testing1)Part 7 contains data that is common to more than one of the parts of ISO 4126 to avoid unnecessary repetition.1) Under preparation.iv ISO 2013 All righ
36、ts reservedCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 4126-1:2013INTERNATIONAL STANDARD ISO 4126-1:2013(E)Safety devices for protection against excessive pressure
37、Part 1: Safety valves1 ScopeThis part of ISO 4126 specifies general requirements for safety valves irrespective of the fluid for which they are designed.It is applicable to safety valves having a flow diameter of 4 mm and above which are for use at set pressures of 0,1 bar gauge and above. No limita
38、tion is placed on temperature.This is a product standard and is not applicable to applications of safety valves.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated reference
39、s, the latest edition of the referenced document (including any amendments) applies.ISO 4126-7:2013, Safety devices for protection against excessive pressure Part 7: Common data3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1safety valvevalve wh
40、ich automatically, without the assistance of any energy other than that of the fluid concerned, discharges a quantity of the fluid so as to prevent a predetermined safe pressure being exceeded, and which is designed to re-close and prevent further flow of fluid after normal pressure conditions of se
41、rvice have been restoredNote 1 to entry: The valve can be characterized either by pop action (rapid opening) or by opening in proportion (not necessarily linear) to the increase in pressure over the set pressure.3.2direct loaded safety valvesafety valve in which the loading due to the fluid pressure
42、 underneath the valve disc is opposed only by a direct mechanical loading device such as a weight, lever and weight, or spring3.3assisted safety valvesafety valve which, by means of a powered assistance mechanism, may additionally be lifted at a pressure lower than the set pressure and will, even in
43、 the event of failure of the assistance mechanism, comply with all the requirements for safety valves given in ISO 4126 ISO 2013 All rights reserved 1Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without l
44、icense from IHS-,-,-BS EN ISO 4126-1:2013ISO 4126-1:2013(E)3.4supplementary loaded safety valvesafety valve which has, until the pressure at the inlet to the safety valve reaches the set pressure, an additional force which increases the sealing forceNote 1 to entry: This additional force (supplement
45、ary load), which may be provided by means of an extraneous power source, is reliably released when the pressure at the inlet of the safety valve reaches the set pressure. The amount of supplementary loading is so arranged that if such supplementary loading is not released, the safety valve will atta
46、in its certified discharge capacity at a pressure not greater than 1,1 times the maximum allowable pressure of the equipment to be protected.Note 2 to entry: Other types of supplementary loaded safety devices are dealt with in ISO 4126-5.3.5set pressurepredetermined pressure at which a safety valve
47、under operating conditions commences to openNote 1 to entry: It is the gauge pressure measured at the valve inlet at which the pressure forces tending to open the valve for the specific service conditions are in equilibrium with the forces retaining the valve disc on its seat.3.6maximum allowable pr
48、essurePSmaximum pressure for which the protected equipment is designed3.7overpressurepressure increase over the set pressureNote 1 to entry: Overpressure is usually expressed as a percentage of the set pressure.3.8reseating pressurevalue of the inlet static pressure at which the disc re-establishes
49、contact with the seat or at which the lift becomes zero3.9cold differential test pressureinlet static pressure at which a safety valve is set to commence to open on the test benchNote 1 to entry: This test pressure includes corrections for service conditions, e.g. back pressure and/or temperature.3.10relieving pressurepressu
