1、BRITISH STANDARDBS EN 14797:2006Explosion venting devicesThe European Standard EN 14797:2006 has the status of a British StandardICS 13.230g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g
2、3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14797:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2007 BSI 2007ISBN 978 0 580 50186 9National forewordThis British Standard was published by BSI. It is the UK implementation of
3、EN 14797:2006.The UK participation in its preparation was entrusted to Technical Committee FSH/23, Fire precautions in industrial and chemical plant.A list of organizations represented on FSH/23 can be obtained on request to its secretary.This publication does not purport to include all the necessar
4、y provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14797December 2006ICS 13.230Englis
5、h VersionExplosion venting devicesDispositifs de dcharge dexplosion Einrichtungen zur ExplosionsdruckentlastungThis European Standard was approved by CEN on 4 November 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Europe
6、anStandard 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 European Standard exists in three official versions (English, Fre
7、nch, 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 national standards bodies of Austria, Belgium, Cyprus, Czech Republi
8、c, 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 Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMAL
9、ISATIONEUROPISCHES 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 14797:2006: EEN 14797:2006 (E) 2 Contents Page Foreword4 1 Scope 5 2 Normative reference
10、s 5 3 Terms and definitions .6 4 Design requirements .8 4.1 General8 4.2 Potential sources of ignition 9 5 Types of explosion venting devices 9 5.1 Explosion venting devices with reusable elements.9 5.2 Explosion venting devices with non reusable elements .9 6 Back pressure supports9 6.1 General9 6.
11、2 Opening back pressure supports 10 6.3 Non-opening back pressure supports.10 7 Testing of explosion venting devices10 7.1 General10 7.2 Static activation pressure .10 7.3 Explosion testing.12 8 Information for use 16 9 Assembly, replacements or reusability.17 10 Marking .17 10.1 General17 10.2 Expl
12、osion venting devices with reusable retaining elements 17 10.3 Explosion venting devices with non-reusable retaining elements.18 10.4 Omission of markings .18 11 Packaging .19 11.1 General19 11.2 Marking .19 Annex A (informative) Examples for explosion venting devices .20 A.1 Re-closing explosion ve
13、nting devices 20 A.2 Devices which require manual repositioning or replacement of the retaining element 21 A.3 Devices with non reusable elements.23 Annex B (informative) Service and maintenance.26 B.1 General26 B.2 Servicing.26 Annex ZA (informative) Relationship between this European Standard and
14、the Essential Requirements of EU Directive 94/9/EC 27 Bibliography 29 Figures Figure 1 Direct comparison method 14 Figure 2 Example for direct comparison method 15 EN 14797:2006 (E) 3 Figure A.1 Example for an explosion door21 Figure A.2 Example for a buckling-rod device22 Figure A.3 Example for a b
15、ursting panel device.23 Figure A.4 Example for a restrained pop-out panel device .24 Figure A.5 Example for a back pressure support.25 Tables Table 1 Symbols and their descriptions8 Table 2 Number of tests of explosion venting devices with non-reusable elements.12 Table ZA.1 Correspondence between t
16、his European Standard and Directive 94/9/EC27 EN 14797:2006 (E) 4 Foreword This document (EN 14797:2006) has been prepared by Technical Committee CEN/TC 305 “Potentially explosive atmospheres - Explosion prevention and protection”, the secretariat of which is held by DIN. This European Standard shal
17、l be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2007, and conflicting national standards shall be withdrawn at the latest by June 2007. This document has been prepared under a mandate given to CEN by the European Commi
18、ssion 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 organizations
19、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, Sl
20、ovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14797:2006 (E) 5 1 Scope This European Standard specifies the requirements for venting devices used to protect enclosures against the major effects of internal explosions arising from the rapid burning of suspended dust, vapour or gas contain
21、ed within. It includes the requirements for the design, inspection, testing, marking, documentation and packaging. This European Standard specifies explosion venting devices which are put on the market as autonomous protective systems. Explosion venting devices are safety devices comprised of a pres
22、sure sensitive membrane fixed to and forming part of the structure that it protects, designed to intervene in the event of an explosion at a predetermined low pressure, to immediately open a vent area sufficient to ensure that the maximum pressure attained by the explosion within the enclosure does
23、not exceed its designed resistance to pressure. The application and specification of explosion venting devices is outlined for dust explosion protection in EN 14491 and for gas explosion protection in prEN 14994. The use of venting devices according to this European Standard on pipelines and on appl
24、ications other than described in EN 14491 or prEN 14994 needs to be carefully evaluated and where appropriate their suitability needs to be confirmed by tests. Flameless explosion venting devices avoid the breakthrough of flames into the surroundings. They are used to allow explosion venting in situ
25、ations where the hazards of flames resulting from the venting action are not acceptable. Flameless explosion venting devices are treated in a separate standard. This European Standard does not cover details for the avoidance of ignition sources from detection devices or other parts of the venting de
26、vices. 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 13237:2003, Pote
27、ntially explosive atmospheres Terms and definitions for equipment and protective systems intended for use in potentially explosive atmospheres EN 13463-1, Non-electrical equipment for potentially explosive atmospheres Part 1: Basic method and requirements EN 14491, Dust explosion venting protective
28、systems prEN 14994:2005, Gas explosion venting protective systems EN 60079-0, Electrical apparatus for explosive gas atmospheres Part 0: General requirements (IEC 60079-0:2004) prEN 61241-0, IEC 61241-0, Ed. 1: Electrical apparatus for use in the presence of combustible dust Part 0: General requirem
29、ents EN 14797:2006 (E) 6 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 13237:2003 and the following apply. 3.1 batch quantity of non-reusable retaining elements made as a single group of the same type, size, materials and specified static activation
30、 pressure requirements when the non-reusable retaining elements are manufactured from the same lot of material 3.2 effective vent area AEproduct of the geometric vent area Adand the venting efficiency Effor the venting device NOTE It is the effective vent area that should be used in making up the ve
31、nt area for explosion venting. 3.3 explosion venting protective measure which will prevent the explosion pressure in a vessel or other closed volume from exceeding the vessel design strength by exhausting the explosion through an explosion venting device in the vessel walls 3.4 explosion venting dev
32、ice device which protects a vessel or other closed volume by explosion venting 3.5 gas explosion constant KGmaximum value of the pressure rise per unit time (dp/dt)maxduring the explosion of a specific explosive atmosphere in a closed vessel under specific test conditions normalized to a vessel volu
33、me of 1 m3multiplied by V1/3 prEN 14994:2005, 3.8 3.6 dust explosion constant Kstmaximum value of explosion pressure rise per unit of time (dp/dt)maxin a volume of 1 m3 multiplied by V1/33.7 retaining element part or parts of the explosion venting device that determines the activation pressure NOTE
34、It may or may not be re-useable. 3.8 reduced explosion pressure predoverpressure generated by an explosion of an explosive atmosphere in an enclosure protected by explosion venting 3.9 restraining element parts of some explosion venting devices that prevent components or objects from becoming danger
35、ous missiles EN 14797:2006 (E) 7 NOTE They may or may not be reusable. 3.10 specific mass total mass per unit area (Ad) of the venting element. The specific mass is used in determining the effect of inertia 3.11 static activation pressure pstatdifferential pressure at which the retaining element act
36、ivates such that the venting element is able to open 3.12 static activation pressure tolerance range range of differential pressure between the specified maximum static activation pressure and the specified minimum static activation pressure or the range of differential pressure in positive and nega
37、tive percentages or quantities which is related to the specified static activation pressure 3.13 vent area Adgeometric vent area of an explosion venting device. NOTE The vent area is the minimum cross-sectional flow area of the explosion venting device taking into consideration the possible reductio
38、n of the cross section, e.g. by back pressure support, restraining devices and parts of the explosion venting device which remain after venting 3.14 venting efficiency Efdimensionless number used to define the efficiency of the explosion venting device as determined in 7.3.4 3.15 venting element par
39、t of the explosion venting device that covers the vent area and opens under explosion conditions NOTE It may or may not incorporate the retaining element - it may or may not be reusable. EN 14797:2006 (E) 8 Table 1 Symbols and their descriptions Symbol Description Units A Required vent area m2AE Eff
40、ective vent area m2 AdGeometric vent area m2EfVenting efficiency - pstatStatic activation pressure bar predReduced explosion pressure bar pred, baselineReduced explosion pressure measured using an explosion venting device with a specific mass 0,5 kg m-2bar pred, test device Reduced explosion pressur
41、e measured using an explosion venting device under investigation bar KG Gas explosion constant bar m s-1Kst Dust explosion constant bar m s-1V Volume of vessel to be protected by explosion venting m34 Design requirements 4.1 General Explosion venting devices shall be designed so that they open when
42、subjected to pressure exceeding their static activation pressure (within a stated static activation pressure tolerance range). Any part not designed to rupture shall not rupture. Venting elements shall be designed so that they shall not fragment to produce dangerous missiles. These requirements may
43、be proved by explosion testing, but other methods e.g. calculation, may be used if their validity has been verified from representative explosion tests. Explosion venting devices shall employ re-usable elements or non re-usable elements (see Clause 5). Explosion venting devices may be provided with
44、back pressure supports (see Clause 6). The performance capability of an explosion venting device is defined by the following parameters: the static activation pressure pstatand its tolerance; the maximum KG/Kstvalues specified by the manufacturer; the maximum reduced pressure predspecified by the ma
45、nufacturer; the minimum venting efficiency Efof the device. Tests to determine or prove these parameters are given in Clause 7. Explosion venting devices shall be designed to maintain their specified performance taking into account environmental and process conditions. Build-up or addition of any su
46、bstance on external surfaces of the device (e.g. snow and ice) and the build-up of product on the internal surfaces of the device may affect the correct operation of the device, so particular attention shall be given to preventing such effects. Material used for the parts of explosion venting device
47、s shall be selected on the basis of their suitability with regard to the chemical and physical conditions to which they will be subjected in service. EN 14797:2006 (E) 9 It is common practice to use electrical detection devices to sense vent function, to operate an alarm or shut plant down. Such det
48、ection devices shall meet the requirements of EN 13463-1, EN 60079-0 and prEN 61241-0. Explosion venting devices can incorporate thermal insulation on the internal or external or both sides to prevent heat loss and/or condensation. Gaskets or seals forming part of an explosion venting device, shall
49、be as specified by the manufacturer and shall be compatible with the chemical, thermal, mechanical and environmental demands of the application. 4.2 Potential sources of ignition Due consideration shall be given to potential sources of ignition in the design and material specification of venting devices, e.g. static electricity, heating and detection devices. Requirements for potential sources of ignition in electrical and non-electrical equipment apply, as stated in EN 13463-1. 5 Types of explosion venting devices 5.1 Explosion venting device
