1、BRITISH STANDARDBS EN ISO 4126-3:2006Safety devices for protection against excessive pressure Part 3: Safety valves and bursting disc safety devices in combination (ISO 4126-3:2006)ICS 13.240g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40
2、g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 4126-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2009 BSI 2009ISBN 978 0 580 53523 9National forewordThis British Standard
3、 is the UK implementation of EN ISO 4126-3:2006. The UK participation in its preparation was entrusted to Technical Committee PVE/12, Safety devices.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the
4、necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 4126-3March 2006ICS
5、13.240English VersionSafety devices for protection against excessive pressure - Part3: Safety valves and bursting disc safety devices in combination(ISO 4126-3:2006)Dispositifs de scurit pour protection contre les pressionsexcessives - Partie 3: Dispositifs de sret combinantsoupapes de sret et disqu
6、es de rupture (ISO 4126-3:2006)Sicherheitseinrichtungen gegen unzulssigen berdruck -Teil 3: Sicherheitsventile und Berstscheibeneinrichtungenin Kombination (ISO 4126-3:2006)This European Standard was approved by CEN on 27 February 2006.CEN members are bound to comply with the CEN/CENELEC Internal Re
7、gulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This Eu
8、ropean Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the natio
9、nal standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdo
10、m.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 4126-3:2006: EForewor
11、d This document (EN ISO 4126-3:2006) has been prepared by Technical Committee CEN/TC 69 “Industrial valves“, the secretariat of which is held by AFNOR, in collaboration with Technical Committee ISO/TC 185 “Safety devices for protection against excessive pressure“. This European Standard shall be giv
12、en the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2006, and conflicting national standards shall be withdrawn at the latest by September 2006. This document has been prepared under a mandate given to CEN by the European Com
13、mission 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 integral part of this document. According to the CEN/CENELEC Internal Regulations, the national standards organization
14、s of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia,
15、Slovenia, Spain, Sweden, Switzerland and United Kingdom. BS EN ISO 4126-3:2006iiiContents Page Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Symbols . 4 5 Design of combination . 5 6 Installation of combination 5 7 Combination performance . 6 8 Determination of c
16、ombination discharge capacity factor, Fd, by testing. 6 9 Derivation of combination discharge capacity factor, Fd. 9 10 Alternative to testing for Fd. 9 11 Certification of combination discharge capacity factor, Fd. 10 12 Application and use of the certified combination discharge capacity factor, Fd
17、10 13 Marking and identification of combination devices 10 14 Certification . 11 15 Preparation for storage and transport 11 BS EN ISO 4126-3:2006Requirements of EU Directive 97/23/EC (PED).12 Annex ZA (informative) Relationship between this International Standard and the Essentialiv Foreword ISO (t
18、he 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 interested in a subject for which a technical commit
19、tee 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 Electrotechnical Commission (IEC) on all matters of electrotech
20、nical 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 technical committees are circulated to the member
21、 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 shall not be held responsible for identifying
22、 any or all such patent rights. ISO 4126-3 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 69, Industrial valves, ISO/TC 185, Safety devices for protection against excessive pressure, in accordance with the Agreement on technical cooperation between ISO an
23、d CEN (Vienna Agreement). This first edition of ISO 4126-3 cancels and replaces ISO 6718:1991, of which it constitutes a technical revision. ISO 4126 consists of the following parts, under the general title Safety devices for protection against excessive pressure: Part 1: Safety valves Part 2: Burst
24、ing disc safety devices Part 3: Safety 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: App
25、lication and installation of safety devices excluding stand-alone bursting disc safety devices Part 7 contains data which is common to more than one of the parts of this standard to avoid unnecessary repetition. BS EN ISO 4126-3:2006vIntroduction Bursting disc safety devices can be used in conjuncti
26、on with safety valves in following cases: a) to protect the safety valve against corrosion, fouling or operating conditions which could affect the safety valve performance; b) to prevent leakage; c) to prevent total loss of contents from the protected equipment following the bursting of the bursting
27、 disc. The term combination is used to describe the close-coupled (i.e. within 5 pipe diameters) assembly of a bursting disc safety device with a safety valve or CSPRS, as defined by this part of ISO 4126. In some cases, the bursting disc safety device and the safety valve or CSPRS are connected tog
28、ether to form the combination by a short length of pipe or a spool piece. BS EN ISO 4126-3:2006blank1Safety devices for protection against excessive pressure Part 3: Safety valves and bursting disc safety devices in combination 1 Scope This part of ISO 4126 specifies the requirements for a product a
29、ssembled from the in-series combination of safety valves or CSPRS (controlled safety pressure relief systems) according to ISO 4126-1, ISO 4126-4 and ISO 4126-5, and bursting disc safety devices according to ISO 4126-2 installed within no more than five pipe diameters from the valve inlet. It specif
30、ies the design, application and marking requirements for such products, which are used to protect pressure vessels, piping or other enclosures from excessive pressure, and which comprise the bursting disc safety device, a safety valve or CSPRS and, where applicable, a short length of connecting pipe
31、 or spool piece. In addition, it gives a method for establishing the combination discharge factor used in sizing combinations. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For u
32、ndated references, the latest edition of the referenced document (including any amendments) applies. ISO 4126-1:2004, Safety devices for protection against excessive pressure Part 1: Safety valves ISO 4126-2:2003, Safety devices for protection against excessive pressure Part 2: Bursting disc safety
33、devices ISO 4126-4:2004, Safety devices for protection against excessive pressure Part 4: Pilot-operated safety valves ISO 4126-5:2004, Safety devices for protection against excessive pressure Part 5: Controlled safety pressure relief systems (CSPRS) ISO 4126-6:2003, Safety devices for protection ag
34、ainst excessive pressure Part 6: Application, selection and installation of bursting disc safety devices EN 764-7:2002, Pressure equipment Part 7: Safety systems for unfired pressure equipment EN 13480-1:2002, Metallic industrial piping Part 1: General EN 13480-2:2002, Metallic industrial piping Par
35、t 2: Materials EN 13480-3:2002, Metallic industrial piping Part 3: Design and calculation EN 13480-4:2002, Metallic industrial piping Part 4: Fabrication and installation EN 13480-5:2002, Metallic industrial piping Part 5: Inspection and testing EN 13480-6:2002, Metallic industrial piping Part 6: Ad
36、ditional requirements for buried piping CEN/TR 13480-7:2002, Metallic industrial piping Part 7: Guidance on the use of conformity assessment procedures BS EN ISO 4126-3:20062 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 combination install
37、ation which comprises a bursting disc safety device installed within five pipe diameters (from outlet of bursting disc holder to inlet of valve) before the inlet of a safety valve or a CSPRS See Figure 1. Key 1 safety valve or CSPRS 2 bursting disc safety device 3 safety valve or CSPRS inlet 4 burst
38、ing disc safety device outlet NOTE Other bursting disc safety device configurations used in conjunction with safety valves or CSPRS are specified in ISO 4126-6. Figure 1 Diagram of combination showing relative distance 3.2 combination discharge capacity factor Fdfactor used to determine the discharg
39、e capacity of a safety valve or CSPRS when the safety valve or CSPRS is used in combination with a bursting disc safety device installed upstream of the safety valve or CSPRS 3.3 flow resistance factor Krfactor which determines the resistance to flow in a pipe work system caused by the presence ther
40、ein of a burst bursting disc, forming part of a bursting disc safety device, installed in the system NOTE Its symbol, Kr, is a dimensionless factor expressed as the velocity head loss. 3.4 bursting disc safety device non-reclosing pressure relief device actuated by differential pressure and designed
41、 to function by the bursting of the bursting disc(s) NOTE It is the complete assembly of installed components including, where appropriate, the bursting disc holder. BS EN ISO 4126-3:200633.5 bursting disc assembly complete assembly of the components installed in the bursting disc holder to perform
42、the desired function 3.6 bursting disc pressure-containing and pressure-sensitive component of a bursting disc safety device 3.7 bursting disc holder part of a bursting disc safety device that retains the bursting disc assembly in position 3.8 specified bursting pressure bursting pressure quoted wit
43、h a coincident temperature when defining the bursting disc requirements NOTE It is used in conjunction with a performance tolerance (3.11). 3.9 specified maximum bursting pressure maximum bursting pressure quoted with the coincident temperature when defining the bursting disc requirements NOTE It is
44、 used in conjunction with a specified minimum bursting pressure (3.10). 3.10 specified minimum bursting pressure minimum bursting pressure quoted with the coincident temperature when defining the bursting disc requirements NOTE It is used in conjunction with a specified maximum bursting pressure (3.
45、9). 3.11 performance tolerance range of pressure between the specified minimum bursting pressure and the specified maximum bursting pressure or the range of pressure in positive and negative percentages or quantities which is related to the specified bursting pressure 3.12 operating pressure pressur
46、e existing at normal operating conditions within the system being protected 3.13 relieving pressure maximum pressure under discharge conditions in the pressurized system NOTE It may differ from the bursting pressure of the bursting disc. 3.14 bursting disc safety device discharge area minimum cross-
47、sectional flow area of the bursting disc safety device, taking into consideration the possible reduction of the cross-section by, for example, back pressure supports, catching devices or parts of the bursting disc which remain after bursting 3.15 batch quantity of bursting discs or bursting disc saf
48、ety devices made as a single group of the same type, size, materials and specified bursting pressure requirements, and where the bursting discs are manufactured from the same lot of material BS EN ISO 4126-3:20064 3.16 bursting pressure value of the differential pressure between the upstream side an
49、d the downstream side of the bursting disc when it bursts 3.17 bursting disc safety device discharge capacity rate at which a bursting disc safety device can discharge fluid after bursting of the bursting disc 3.18 replacement period time period beginning at the installation of a bursting disc assembly and ending with its replacement 3.19 pressure relief system system intended for the safe relief of fluids from pressure equipment for prevention of excessive pressure NOTE It can consist of equipment nozzle, inlet piping, pressure r
