00345670 PDF BRITISH STANDARD BS EN 439 1994 Welding consumables — Shielding gases for arc welding and cutting The European Standard EN 439 1994 has the status of a British Standard UDC 621 791 04 403[.]
BRITISH STANDARD Welding consumables — Shielding gases for arc welding and cutting The European Standard EN 439:1994 has the status of a British Standard UDC 621.791.04-403:621.791.754 BS EN 439:1994 BS EN 439:1994 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom This British Standard, having been prepared under the direction of the Welding Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 December 1994 © BSI 02-1999 The following BSI references relate to the work on this standard: Committee reference WEE/39 Draft for comment 91/70924 DC ISBN 580 23240 Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standard Suomen Standardisoimisliito, r.y Association franỗaise de normalisation Deutsches Institut für Normung e.V Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Nederlands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portugs da Qualidade Asociación Espola de Normalización y Certificación Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 439:1994 Contents Cooperating organizations National foreword Foreword Text of EN 439 National annex NA (informative) Committees responsible © BSI 02-1999 Page Inside front cover ii Inside back cover i BS EN 439:1994 National foreword This British Standard has been prepared under the direction of the Welding Standards Policy Committee and is the English language version of EN 439:1994 Welding consumables — Shielding gases for arc welding and cutting, published by the European Committee for Standardization (CEN) National annex NA gives the constitution of the committees responsible for UK participation in the preparation of this standard A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages to 6, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 02-1999 EUROPEAN STANDARD EN 439 NORME EUROPÉENNE August l994 EUROPÄISCHE NORM UDC 621.791.04-403:621.791.754 Descriptors: Welding, arc welding, gas shielded gases, gas mixtures, classifications, designation, chemical properties English version Welding consumables Shielding gases for arc welding and cutting Produits consommables pour le soudage — Gaz de protection pour le soudage et le coupage l’arc Schweißzusätze — Schutzgase zum Lichtbogenschweißen und Schneiden This European Standard was approved by CEN on 1994-08-17 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate 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 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 translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1994 Copyright reserved to CEN members Ref No EN 439:1994 E EN 439:1994 Foreword This European Standard was prepared by the Technical Committee CEN/TC 121, Welding, the secretariat of which is held by DS 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 February 1995, and conflicting national standards shall be withdrawn at the latest by February 1995 According to the Common CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom Contents Foreword Scope Properties of gases Classification of shielding gases Designation Tolerances of mixtures Purities and dew point Forms of supply 7.1 Gas cylinders 7.2 Liquid Shielding gas identification Figure — Cylinder pressure-temperature diagram for argon (II) at constant cylinder Table — Properties of gases Table — Classification of shielding gases for are welding and cutting Table — Identification numbers for gases in groups R and M containing helium Table — Purities and dew points of gases and gas mixtures Page 3 3 3 4 6 © BSI 02-1999 EN 439:1994 Scope This standard is applicable to gas shielded arc welding and cutting processes with gases and gas mixtures defined within Applications include, but are not limited to: — tungsten inert gas (TIG) welding; — metal active gas (MAG) welding; — metal inert gas (MIG) welding; — plasma arc welding (PAW); — plasma arc cutting (PAC); — back shielding The purpose of this standard is to classify shielding gases in accordance to their chemical properties as a base for the approval of shielding gas and filler wire combinations Gas purities and mixing tolerances are also specified Properties of gases The physical and chemical properties are listed in Table Classification of shielding gases Table classifies into groups the various component/composition combinations of shielding gases according to their reaction behaviour The symbols used for classification groups are: — R: reducing gas mixtures; — I: inert gases and inert mixtures; — M: oxidizing mixtures containing oxygen, carbon dioxide or both; — C: highly oxidizing gas and highly oxidizing mixtures; — F: unreactive gas or reducing gas mixtures Shielding gas EN 439 — M24 If argon is partly replaced by helium, the helium content is designated by an additional identification number, see Table This identification number is added in brackets as a suffix Example 3: A gas mixture M21 containing 25 % helium is designated: Shielding gas EN 439 — M21 (1) Special gases shall be designated by the prefix S followed by the base gas or mixture symbol as in Table 2, followed by the percent concentration by volume and chemical formula of the additional gases S (designation) + % chemical symbol Example 4: A special gas mixture containing 10 % carbon dioxide, % oxygen and balance argon, designation M24, but also containing 2,5 % neon is designated: Shielding gas EN 439 — S M24 + 2,5Ne Tolerances of mixtures For component concentrations up to % by volume the permissible deviation shall not exceed ± 0,5 % by volume from the specified value For component concentrations of between % by volume and 50 % by volume the concentration shall not vary by more than ± 10 % of the specified value Purities and dew point Where components not listed in Table are added to one of these classifications it is designated as a special gas mixture and carries the prefix S Details of the S designation are given in clause The minimum purities and maximum dew points of gases as delivered in cylinders or insulated tanks, are specified in Table according to their classifications in Table Purities and dew points for special gas mixtures shall correspond to the base gases or gas mixtures used, as specified in Table For some materials, e.g titanium and tantalum, gases of higher purities may be required and specifications can be agreed between the user and the supplier The user’s gas supply system should be designed and maintained such that the purity as delivered is maintained up to the point of use Designation Forms of supply Shielding gases are designated by the term “shielding gases”, the number of this standard, group and identification number according to Table Example 1: A gas mixture containing 30 % helium, and balance argon is designated: Shielding gas EN 439 — 13 Example 2: A gas mixture containing 10 % carbon dioxide, % oxygen and balance argon is designated: Shielding gases are supplied in the gaseous or liquid state either as single gas or gas mixture Where gas mixtures are prepared on site from individual gases, the mixing system shall be designed and maintained such that the tolerance and the purity specified in clauses and can be achieved and maintained © BSI 02-1999 EN 439:1994 7.1 Gas cylinders With the exception of carbon dioxide, all the gases and gas mixtures listed in Table are fully in the gaseous state when supplied in gas cylinders The gas cylinders for the gases listed in Table are filled to a stated volume and pressure as indicated by the supplier The actual pressure will vary with the ambient temperature, e.g the pressure of argon (I1) will vary as in Figure Suitable regulators shall be fitted to the gas cylinder before use 7.2 Liquid In order to produce gas mixtures from liquified gases, the liquids have to be converted to the gaseous state prior to mixing Argon-oxygen mixtures can also be stored pre-mixed as a liquid without using a mixer for the supply NOTE In plasma arc cutting, gas mixing can take place inside the machine from individual gases or gas mixtures Shielding gas identification The designation of the shielding gas according to clause has to be provided with or without the term “shielding gases” Liquefied gases will be supplied as low temperature (cryogenic) liquids in insulated tanks or, in the case of carbon dioxide, as a liquid at ambient temperature in gas cylinders Before use liquified gases supplies have to be converted into the gaseous state Table — Properties of gases Type of gas Chemical symbol Specified at °C and 1,013 bar (0,101 MPa) Density (air = 1,293) Relative density to air kg/m3 Boiling point at 1,013 bar Reaction behaviour during welding °C Argon Ar 1,784 1,380 – 185,9 Inert Helium He 0,178 0,138 – 268,9 Inert Carbon dioxide CO2 1,977 1,529 – 78,5a Oxidizing Oxygen O2 1,429 1,105 – 183,0 Oxidizing Nitrogen N2 1,251 0,968 – 195,8 Unreactiveb Hydrogen H2 0,090 0,070 – 252,8 Reducing a Sublimation b temperature (solid to gas transition temperature) The behaviour of nitrogen varies with different materials Possible negative influences shall be considered © BSI 02-1999 © BSI 02-1999 Table — Classification of shielding gases for arc welding and cutting Group R Symbola Identification No Oxidizing CO2 Components in percent volume Inert Reducing O2 Ar He H2 Balance2 > to 15 Balance2 > 15 to 35 I 100 M1 > to 100 Balance > to 95 Balance2 > to Balance2 ) ) M2 > to > to 25 M3 a Where Balance2 > to Inert Slightly oxidizing > to Balance2 ) ) Balance2 MAG ) > to 10 Balance2 ) > to > to 10 Balance2 > to 25 > to Balance2 > 25 to 50 ) ) Balance2 ) > 10 to 15 Balance2 ) > to 50 > to 15 100 Balance > to 30 MIG, TIG, plasma arc welding, back shielding Reducing Balance2 ) 100 > to 50 Balance Plasma arc cutting, back shielding More pronounced oxidation Unreactive Reducing components not listed are added to one of the groups in this table, the gas mixture is designated as special gas mixture and carries the prefix S Details of the S designation are given in clause 2) Argon may be replaced by up to 95 % helium The helium content is designated by an additional identification number, see clause 4, and is given in Table EN 439:1994 F TIG plasma arc welding, plasma arc cutting, back shielding Remarks ) > to 3 C ) Typical applications Unreactive N2 EN 439:1994 Table — Identification numbers for gases in groups R and M containing helium Identification number Table — Purities and dew points of gases and gas mixtures Groupa Helium content in volume % (1) > to 33 (2) > 33 to 66 (3) > 66 to 95 Purity % by vol Dew point at 1,013 bar Moisture °C max p.p.m max R 99,95 – 50 40 I 99,99 – 50 40 M1 99,70 – 50 40 M2 99,70 – 44 80 M3 99,70 – 40 120 C 99,70 – 35 200 F 99,50 – 50 40 Oxygen 99,50 – 35 200 Hydrogen 99,50 – 50 40 a Data for oxygen and hydrogen have been included in this table Figure — Cylinder pressure-temperature diagram for argon (I1) at constant cylinder content © BSI 02-1999 BS EN 439:1994 National annex NA (informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Welding Standards Policy Committee (WEE/-) to Technical Committee WEE/39 upon which the following bodies were represented: Aluminium Federation Associated Offices Technical Committee Association of Welding Distributors British Association for Brazing and Soldering British Compressed Gases Association British Constructional Steelwork Association Ltd British Steel Industry Electricity Association Engineering Equipment and Materials Users’ Association Lloyd’s Register of Shipping Magnesium Industry Council Power Generation Contractors’ Association [PGCA (BEAMA Ltd.)] Process Plant Association Stainless Steel Wire Industry Association Suffolk Lawn Mowers Ltd Welding Institute Welding Manufacturers’ 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