1、BRITISH STANDARDBS EN 14797:2006Explosion venting devicesThe European Standard EN 14797:2006 has the status of a British StandardICS 13.230g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g
2、3g38g50g51g60g53g44g42g43g55g3g47g36g58Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIBS 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 9N
3、ational forewordThis British Standard was published by BSI. It is the UK implementation of 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 obtaine
4、d on request to its secretary.This publication does not purport to include all the necessary 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 C
5、ommentsLicensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14797December 2006ICS 13.230English VersionExplosion venting devicesDispositifs de dcharge dexplosion Einrichtungen zur ExplosionsdruckentlastungThis Eu
6、ropean 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 EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references c
7、oncerning 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, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own
8、 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 Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg,
9、 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: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exp
10、loitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14797:2006: ELicensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14797:2006 (E) 2 Contents Page Foreword4 1 Scope 5 2 Normative references 5 3 Terms and definitions
11、 .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 6.2 Opening back pressure sup
12、ports 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 Explosion venting devices with
13、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 venting devices 20 A.2 Device
14、s 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 the Essential Requirements
15、of EU Directive 94/9/EC 27 Bibliography 29 Figures Figure 1 Direct comparison method 14 Figure 2 Example for direct comparison method 15 Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14797:2006 (E) 3 Figure A.1 Example for an explosion door21 Figure A.
16、2 Example for a buckling-rod device22 Figure A.3 Example for a bursting 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 w
17、ith non-reusable elements.12 Table ZA.1 Correspondence between this European Standard and Directive 94/9/EC27 Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14797:2006 (E) 4 Foreword This document (EN 14797:2006) has been prepared by Technical Committee
18、 CEN/TC 305 “Potentially explosive atmospheres - Explosion prevention and protection”, the secretariat of which is held by DIN. 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 2007, and confl
19、icting 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 Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see
20、 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, Fr
21、ance, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BS
22、IEN 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 contained within. It includes the requirements for the design
23、, 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 pressure sensitive membrane fixed to and forming part of t
24、he 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 not exceed its designed resistance to pressure. The ap
25、plication 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 applications other than described in EN 14491 or prEN 1499
26、4 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 situations where the hazards of flames resulting from the
27、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 devices. 2 Normative references The following referenced
28、 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, Potentially explosive atmospheres Terms and definitions fo
29、r 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 systems prEN 14994:2005, Gas explosion venting protect
30、ive 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 requirements Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34
31、GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 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, mate
32、rials and specified static activation 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 th
33、at should be used in making up the vent 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 v
34、essel walls 3.4 explosion venting device 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 c
35、onditions normalized to a vessel volume 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 det
36、ermines the activation pressure NOTE 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 compo
37、nents or objects from becoming dangerous missiles Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 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
38、 determining the effect of inertia 3.11 static activation pressure pstatdifferential pressure at which the retaining element activates 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 act
39、ivation pressure and the specified minimum static activation pressure or the range of differential pressure in positive and negative 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 ve
40、nt area is the minimum cross-sectional flow area of the explosion venting device taking into consideration the possible reduction 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 Efdi
41、mensionless number used to define the efficiency of the explosion venting device as determined in 7.3.4 3.15 venting element part 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 no
42、t be reusable. Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14797:2006 (E) 8 Table 1 Symbols and their descriptions Symbol Description Units A Required vent area m2AE Effective vent area m2 AdGeometric vent area m2EfVenting efficiency - pstatStatic ac
43、tivation 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 pressure measured using an explosion venting device under investigation bar KG Gas explo
44、sion 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 subjected to pressure exceeding their static activation pressure (within a stated
45、 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 be proved by explosion testing, but other methods e.g. calculation, may be used i
46、f 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 back pressure supports (see Clause 6). The performance capability of an explosion
47、 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 manufacturer; the minimum venting efficiency Efof the device. Tests to determine or
48、 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 substance on external surfaces of the device (e.g. snow and ice) and the build-up o
49、f 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 devices 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. Licensed Copy: Wang Bin, na, Wed Apr 11 02:13:34 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14797:2006 (E) 9 It is common practice to use electrical detection devices to sense ve
