1、BRITISH STANDARDBS EN 14986:2007Design of fans working in potentially explosive atmospheresThe European Standard EN 14986:2007 has the status of a British StandardICS 23.120; 29.260.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g
2、3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIBS EN 14986:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30
3、April 2007 BSI 2007ISBN 978 0 580 50397 9National forewordThis British Standard was published by BSI. It is the UK implementation of EN 14986:2007.The UK participation in its preparation was entrusted to Technical Committee FSH/23, Fire precautions in industrial and chemical plant.This harmonized Eu
4、ropean Standard gives requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres.During the development of this standard, it became evident that many of the technical
5、issues relating to preventing ignition risks had not been fully researched, that manufacturers across Europe had developed quite different approaches to controlling the risks, and that it was not straightforward to link the design features required to an ATEX category.There were strong views express
6、ed by those with experience of explosion protected electrical equipment and the corresponding standards that this CEN standard could create conflicts with the requirements for integral cooling fans on electric motors (which have been standardized over many years), and confusion where a fan and motor
7、 combination was sold as a single item.Where performance efficiency is not a key requirement, as in the case of cooling fans for motors, very rigid construction and comparatively large separation between moving and fixed parts may be appropriate, thus minimizing the risk of contact and the associate
8、d ignition risk. For good economic and technical reasons other types of fans need to be made with less rigid casings, and less clearance between the blades and the casing. It is however, very difficult to measure the minimum clearance achieved.For fans that are not an integral part of a motor that m
9、ay be exposed to flammable atmospheres correct selection of materials for the blades and casing can reduce the ignition risk in the case of high speed rubbing contact, but the material pairings that should be acceptable for different circumstances were the subject of extended discussion.The list of
10、acceptable material pairings found in Table 2 represents a compromise based on existing practice by different manufacturers, and detailed technical justification for all the combinations is not available. It is possible that with further work, other useful combinations may be found that will achieve
11、 a similar level of safety.For all these reasons, users should recognize that this standard cannot specify all possible ways of making ATEX compliant fans, and that alternative approaches may be equally valid. The standard represents the state of the art but there is clearly room for development in
12、the future.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 necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer imm
13、unity from legal obligationsAmendments issued since publicationAmd. No. Date CommentsLicensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14986February 2007ICS 23.120; 29.260.20English VersionDesign of fans worki
14、ng in potentially explosive atmospheresConception des ventilateurs pour les atmosphresexplosiblesKonstruktion von Ventilatoren fr den Einsatz inexplosionsgefhrdeten BereichenThis European Standard was approved by CEN on 13 January 2007.CEN members are bound to comply with the CEN/CENELEC Internal Re
15、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 CEN Management Centre or to any CEN member.This
16、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 language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the n
17、ational standards bodies of Austria, Belgium, Bulgaria, 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
18、 United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14986:2007:
19、 ELicensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .6 4 Requirements for all fans6 5 Additional requirements for category 2 fans 16 6 Categ
20、ory 1 fans for use with gas as the conveyed fluid17 7 Information for use 18 Annex A (normative) Additional requirements for category 1 G fans .21 Annex B (informative) Checklist for verification of the safety requirements and/or protective measures24 Annex C (informative) Examples of types of fans
21、showing ignition minimising features.26 Annex D (normative) List of significant hazards .31 Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Directive 94/9/EC .34 Bibliography 35 Figures Figure A.1 Test apparatus for the flame transmission test
22、.22 Figure C.1 Axial fan with fixed pitch blades and ducted inlet for categories 2 and 3.26 Figure C.2 Axial fan with variable pitch in-motion ducted inlet-box arrangement27 Figure C.3 Mixed flow belt driven ducted fan28 Figure C.4 Centrifugal fan - ducted arrangement .29 Figure C.5 Typical fan driv
23、e belt guard details .30 Tables Page Table 1 Permissible material pairings for gas explosion groups IIA and IIB.11 Table 2 Permissible material pairings for gas mixtures containing hydrogen13 Table 3 Minimum thickness of linings .13 Table D.1 Identification of hazards and required countermeasures.31
24、 Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 3 Foreword This document (EN 14986:2007) has been prepared by Technical Committee CEN/TC 305 “Potentially explosive atmospheres - Explosion prevention and protection”, the secretariat of whi
25、ch 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 August 2007, and conflicting national standards shall be withdrawn at the latest by August 2007. This document has been prepared
26、under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive 94/9/EC. For relationship with EU Directive 94/9/EC, see informative Annex ZA, which is an integral part of this document. According to the CEN/CENELEC
27、 Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembour
28、g, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 4 Introduction This European Standard is a type C standard as stat
29、ed in EN ISO 12100-1. The machinery concerned and the extent to which hazards, hazardous situations and events are covered and indicated in the scope of this European Standard. When provisions of this type C standard are different from those, which are stated in type A or B standards, the provisions
30、 of this type C standard take precedence over the provisions of the other standards, for machines that have been designed and built according to the provisions of this type C standard. Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 5 1 Sc
31、ope 1.1 This European Standard specifies the constructional requirements for fans constructed to Group II G (of explosion groups IIA, IIB and hydrogen) categories 1, 2 and 3, and Group II D categories 2 and 3, intended for use in explosive atmospheres. NOTE Operation conditions for the different cat
32、egories of fans used in this European Standard are defined in Clause 4. 1.2 This European Standard does not apply to group I fans (fans for mining), cooling fans or impellers on rotating electrical machines, cooling fans or impellers on internal combustion engines. NOTE 1 Requirements for group I fa
33、ns are given in EN 1710. NOTE 2 The requirements for electrical parts are covered by references to electrical equipment standards. 1.3 This European Standard specifies requirements for design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospher
34、es in air containing gas, vapour, mist and/or dusts. Such atmospheres may exist inside (the conveyed fluid), outside, or inside and outside of the fan. 1.4 This European Standard is applicable to fans working in the range of ambient atmospheres having absolute pressures ranging from 0,8 bar to 1,1 b
35、ar, temperatures ranging from 20 C to + 60 C, maximum volume fraction of 21 % oxygen content and an aerodynamic energy increase of less than 25 kJ/kg. NOTE 1 This European Standard may also be helpful for the design, construction, testing and marking of fans intended for use in atmospheres outside t
36、he validity range stated above or in cases where other material pairings need to be used. In this case, the ignition risk assessment, ignition protection provided, additional testing (if necessary), manufacturers marking, technical documentation and instructions to the user, should clearly demonstra
37、te and indicate the equipments suitability for the conditions the fan may encounter. NOTE 2 This European Standard does not apply to integral fans of electric motors. NOTE 3 Where undated references are used in the body of the standard the latest edition applies. 2 Normative references The following
38、 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 294, Safety of machinery Safety distance to prevent danger
39、zones being reached by the upper limbs EN 1050, Safety of machinery Principles for risk assessment EN 1127-1:1997, Explosive atmospheres Explosion prevention and protection Part 1: Basic concepts and methodology EN 12874:2001, Flame arresters Performance requirements, test methods and limits for use
40、 EN 13463-1:2001, Non-electrical equipment for potentially explosive atmospheres Part 1: Basic method and requirements EN 13463-5, Non-electrical equipment intended for use in potentially explosive atmospheres Part 5: Protection by constructional safety “c“ EN 13463-6, Non-electrical equipment for u
41、se in potentially explosive atmospheres Part 6: Protection by control of ignition source “b“ Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 6 EN 50281-1-1, Electrical apparatus for use in the presence of combustible dust Part 1-1: Electri
42、cal apparatus protected by enclosures Construction and testing EN 60079-0, Electrical apparatus for explosive gas atmospheres Part 0: General requirements (IEC 60079-0:2004) EN 60529, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989) EN ISO 12100-1, Safety of machinery Basic co
43、ncepts, general principles for design Part 1: Basic terminology, methodology (ISO 12100-1:2003) EN ISO 12100-2, Safety of machinery Basic concepts, general principles for design Part 2: Technical principles (ISO 12100-2:2003) ISO 12499, Industrial fans Mechanical safety of fans Guarding ISO 13349:19
44、99, Industrial fans Vocabulary and definitions of categories ISO 14694:2003, Industrial fans Specifications for balance quality and vibration levels 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1127-1:1997, EN 12874:2001 and EN 13463-1:2001 and the
45、 following apply. 3.1 externally mounted flame arrester flame arrester with flame arrester housing and flame arrester elements directly mounted as a separate equipment on the fan 3.2 integrated flame arrester flame arrester where flame arrester housing and flame arrester elements are part of the fan
46、 3.3 contact diameter diameter of a rotating part at the point where it can contact a stationary part 4 Requirements for all fans 4.1 General All fans within the scope of this European Standard shall comply with the requirements contained in EN 13463-1 unless otherwise stated in this European Standa
47、rd. NOTE This European Standard deals only with the prevention of ignition of an explosive atmosphere by the fan. Other safety features will need to be incorporated into the construction to meet the requirements of other EU Directives. For example by incorporating the principles of EN ISO 12100 for
48、preventing mechanical hazards, (e.g. guarding to prevent persons contacting rotating parts, sharp edges). 4.2 Ignition hazard assessment 4.2.1 General A list of hazards which can occur is given in Annex D. Where additional hazards could occur an ignition hazard assessment according to EN 13463-1 sha
49、ll be carried out. Licensed Copy: Wang Bin, na, Mon May 28 05:57:29 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEN 14986:2007 (E) 7 For the purposes of fans made according to this European Standard the following operational conditions shall be used as a basis for the ignition hazard assessment and for the assignment of a fan to a particular category. Release of flammable material shall be considered in the ignition hazard assessment for the outside of the fan, see 4.3. 4.2.2 Normal operating conditions Norma
