1、|BRITISH STANDARDBS EN746-3:1997ICS 25.180.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWIndustrialthermoprocessingequipmentPart 3: Safety requirements for thegeneration and use of atmosphere gases+A1:2009National forewordThis British Standard is the UK implementation of EN
2、 746-3:1997+A1:2009. It supersedes BS EN 746-3:1997 which is withdrawn.The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to CEN text carry the number of the CEN amendment. For example, text altered by CEN amendment Al is indicat
3、ed by !“.The UK participation in its preparation was entrusted byTechnical Committee MCE/3, Safeguarding of machinery, to Subcommittee MCE/3/8, Thermoprocessing equipment Safety.A list of organizations represented on this subcommittee can be obtained on request to its secretary.This publication does
4、 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.BS EN 746-3:1997+A1:2009This British Standard was published under the authority of the Standards Boar
5、d and comes into effect on 15 September 1997 BSI 2009Amendments/corrigenda issued since publicationDate Text affected31 October 2009 Implementation of CEN amendment A1:2009ISBN 978 0 580 63146 7EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 746-3:1997+A1 June 2009 ICS 25.180.01 Supersedes EN 7
6、46-3:1997English Version Industrial thermoprocessing equipment - Part 3: Safety requirements for the generation and use of atmosphere gases Equipements thermiques industriels - Partie 3: Prescriptions de scurit pour la gnration et lutilisation des gaz datmosphre Industrielle Thermoprozessanlagen - T
7、eil 3: Sicherheitsanforderungen fr die Erzeugung und Anwendung von Schutz- und Reaktionsgasen This European Standard was approved by CEN on 19 March 1997 and includes Amendment 1 approved by CEN on 21 May 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate
8、 the conditions for giving this European Standard 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 Management Centre or to any CEN member. This European Standard exis
9、ts in three official versions (English, French, 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 Management Centre has the same status as the official versions. CEN members are the national standards b
10、odies 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 United Kingdom.
11、EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 746-3:1997+A1:2009: EEN
12、746-3:1997+A1:2009 (E) 2 Contents Page Foreword 3Introduction .51 Scope 52 Normative references 63 Definitions 74 List of hazards . 105 Safety requirements for the use of atmosphere gases. 165.1 Purging 165.2 Safety control equipment for atmosphere gases 175.3 Thermo-processing equipment requirement
13、s . 186 Safety requirements for atmosphere gas generators . 226.1 Reaction gas supplies 226.2 Fuel gas supplies 236.3 Air supplies . 236.4 Mixture supplies 246.5 Electrical supplies 246.6 Cooling water supplies and discharge . 246.7 Atmosphere gas supplies and distribution 256.8 System requirements
14、. 257 Verification of the safety requirements and/or measures 278 Information for use . 278.1 Instruction handbook . 278.2 Marking 30Annex A (informative) Typical Atmosphere Gases . 31Annex B (informative) Explosion Hazards of Gas Mixtures Containing Combustibles 32Annex C (informative) Inert Gas Pu
15、rging . 34Annex D: Bibliography 36Annex E (informative) Used Definitions . 37Annex ZA (informative) !Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC“ 40Annex ZB (informative) !Relationship between this European Standard and the Essential Requiremen
16、ts of EU Directive 2006/42/EC“ 41BS EN 746-3:1997+A1:2009EN 746-3:1997+A1:2009 (E) 3 Foreword This document (EN 746-3:1997+A1:2009) has been prepared by Technical Committee CEN/TC 186 “Industrial thermoprocessing - Safety”, the secretariat of which is held by DIN. This European Standard shall be giv
17、en the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2009, and conflicting national standards shall be withdrawn at the latest by December 2009. This document includes Amendment 1, approved by CEN on 2009-05-21. This document s
18、upersedes EN 746-3:1997. The start and finish of text introduced or altered by amendment is indicated in the text by tags ! “. The working group that drafted this Part of EN 746 comprised experts from the following countries: France, Germany, Italy, Switzerland and the United Kingdom. This standard
19、forms one part of safety standards covering Industrial Thermoprocessing Equipment. The full list of parts of this standard is given below: EN 746 Industrial Thermoprocessing Equipment Part 1: Common Safety Requirements for Industrial Thermoprocessing Equipment Part 2: Safety Requirements for Combust
20、ion and Fuel Handling Systems Part 3: Safety Requirements for the Generation and Use of Atmosphere Gases Part 4: Particular Safety Requirements for Hot Dip Galvanising Thermoprocessing Equipment Part 5: Particular Safety Requirements for Salt Bath Thermoprocessing Equipment Part 6: Particular Safety
21、 Requirements for Material Melting, Remelting and Liquid Phase Maintaining Thermoprocessing Equipment Part 7: Particular Safety Requirements for Vacuum Thermoprocessing Equipment Part 8: Particular Safety Requirements for Quenching Equipment This document has been prepared under a mandate given to C
22、EN 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 informative Annexes ZA and ZB, which are integral parts of this document.“ An assessment of the foreseeable risks arising from th
23、e use of the equipment was carried out when this standard was prepared. BS EN 746-3:1997+A1:2009EN 746-3:1997+A1:2009 (E) 4 According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgi
24、um, 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 United Kingdom. BS EN 746-3:1997+A1:200
25、9EN 746-3:1997+A1:2009 (E) 5 Introduction This standard has been prepared to be a harmonised standard to provide one means of conforming to the Essential requirements of the Machinery Directive and associated EFTA Regulations. The extent to which hazards are covered is indicated in the scope of this
26、 standard. In addition, machinery shall comply as appropriate with !EN ISO 12100-1 and EN ISO 12100-2“ for hazards which are not covered by this standard. This European Standard is a type-C standard as defined in !EN ISO 12100-1 and EN ISO 12100-2“. !EN 746-1 contains the common safety provisions fo
27、r all types of industrial thermoprocessing equipment. This part of the standard details in addition those extra safety requirements for the equipment listed in the scope, which need special attention.“ The equipment dealt with and the extent to which hazards are covered are indicated in the scope of
28、 this part of EN 746. Where for clarity an example of a preventative measure is given in the text, this should not be considered as the only possible solution. Any other solution leading to the same risk reduction is permissible if an equivalent level of safety is achieved. This part of EN 746 assum
29、es that the installations are operated and maintained by trained personnel. 1 Scope This part of EN 746 specifies safety requirements for atmosphere gas systems and their use in industrial thermo-processing equipment and associated plant, including systems for the production of atmosphere gases by r
30、eaction inside the thermo-processing equipment. It applies to the supply of atmosphere gases, gaseous and liquid additions to, and their removal from industrial thermo-processing equipment and associated plant, confined to equipment integrated in the thermo-processing and associated plant. This part
31、 of EN 746 also details the anticipated significant hazards associated with atmosphere gas systems and their use in industrial thermo-processing equipment and specifies the appropriate preventative measures for the reduction or elimination of these hazards. This part of EN 746 does not apply to atmo
32、sphere process gases, essential safety equipment, start-up, operation and shut-down of thermo-processing plant for semi-conductor devices for which special additional engineering requirements are necessary. This part of EN 746 specifies the requirements to be met to ensure the safety of persons and
33、property during commissioning, start up, operation, shut down and maintenance, as well as in the event of foreseeable faults or malfunctions which can occur in the equipment. It specifies the safety requirements at stages in the life of the equipment, and its design, ordering, construction and use.
34、This part of EN 746 applies to equipment which is placed on the market after the date of issue of this standard. The hazards covered by this Part of EN 746 are listed in clause 4. A table of typical atmosphere gases is given in Annex A. BS EN 746-3:1997+A1:2009EN 746-3:1997+A1:2009 (E) 6 2 Normative
35、 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 88-1, Pressure regulators and a
36、ssociated safety devices for gas appliances Part 1: Pressure regulators for inlet pressures up to and including 500 mbar“ EN 161, Automatic shut-off valves for gas burners and gas appliances !deleted text“ EN 298, Automatic gas burner control systems for gas burners and gas burning appliances with o
37、r without fans EN 746-1, Industrial thermoprocessing equipment Part 1: Common safety requirements for Industrial Thermoprocessing Equipment EN 746-2, Industrial thermoprocessing equipment Part 2: Safety requirements for combustion and fuel handling systems EN 60204-1, Safety of machinery Electrical
38、equipment of machines Part 1: General requirements !(IEC 60204-1:2005, modified)“ EN 60519-1, Safety in electroheat installations Part 1: General requirements !(IEC 60519-1:2003)“ EN 60519-2, Safety in electroheat installations Part 2: Particular requirements for resistance heating equipment !(IEC 6
39、60519-2:2006)“ !EN ISO 12100-1:2003, Safety of machinery Basic concepts, general principles for design Part 1: Basic terminology, methodology (ISO 12100-1:2003)“ !EN ISO 12100-2:2003, Safety of machinery Basic concepts, general principles for design Part 2: Technical principles (ISO 12100-2:2003)“ !
40、IEC 60364-4-41, Low-voltage electrical installations Part 4-41: Protection for safety Protection against electric shock“ !IEC 60364-43, Electrical installations of buildings Part 4-43: Protection for safety Protection against overcurrent“ !deleted text“ !IEC 60364-4-44, Low-voltage electrical instal
41、lations Part 4-44: Protection for safety Protection against voltage disturbances and electromagnetic disturbances“ !deleted text“ !IEC 60519-3, Safety in electroheat installations Part 3: Particular requirements for induction and conduction heating and induction melting installations“ BS EN 746-3:19
42、97+A1:2009EN 746-3:1997+A1:2009 (E) 7 3 Definitions For the purposes of this standard the following definitions apply: NOTE An alphabetic listing of the definitions, as well as their cross-references in German, French and English are given in informative Annex E. 3.1 industrial thermo-processing and
43、 associated equipment Any equipment through or into which the atmosphere gases flow NOTE This includes atmosphere gas distribution systems, safety control equipment and the furnace or other enclosures in which atmosphere gases are used. 3.2 safe ignition temperature the minimum temperature at which
44、spontaneous, safe auto-ignition of flammable gases occurs NOTE The safe ignition temperature has been established at 750 C. 3.3 purging the general displacement of one type of atmosphere within a thermal processing plant by another 3.4 flammable atmosphere gas any gas mixture that is capable of form
45、ing flammable mixtures with air or oxygen under the conditions of temperature and pressure used in the process NOTE 1 Typically any gas mixture containing more than 5% (V/V) combustibles (H2+CO+CH4) of which CH4is not more than 1% (V/V), where the remainder of the mixture is non-flammable, is consid
46、ered to be flammable. Any gas mixture which contains more than 1% (V/V) CnHmor 2,5% (V/V) or 2,5% (V/V) NH3where the remainder of the mixture is non-flammable is also considered to be flammable (see Annexes A and B). NOTE 2 A flammable gas which contains 1 % (V/V) or less oxygen cannot in itself for
47、m an explosive or flammable mixture. 3.5 non-flammable atmosphere gas any gas mixture which is not capable of forming flammable mixtures with air or oxygen under the conditions of temperature and pressure used in the process NOTE Typically any gas mixture containing 5% (V/V) or less of combustibles
48、(H2+CO+CH4) of which CH4is not more than 1% of the 5% (V/V) and the remainder is non-flammable and which will not support combustion. 3.6 inert gas a non-flammable gas which will not support combustion and does not react to produce a flammable gas NOTE 1 An inert gas can safely be used for pre- and
49、post-purging of cold and hot enclosures of thermo-processing equipment. NOTE 2 Inert gas can be produced by appropriate adjustment of an exothermic generator. In the event of malfunction such as gas can be flammable and provisions should be taken to ensure that adjustment is correct. 3.7 toxic atmosphere gas
