1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Health and safety in welding and allied processes Requirements, testing and marking of equipment for air filtrationPart 3: Determination of the capture efficiency of on-torch welding fume extraction devices (ISO 21904-3
2、:2018)BS EN ISO 21904-3:2018National forewordThis British Standard is the UK implementation of EN ISO 21904-3:2018.The UK participation in its preparation was entrusted to Technical Committee WEE/40, Health and safety in welding.A list of organizations represented on this committee can be obtained o
3、n 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. The British Standards Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0 580 97262 1ICS 25.160.01; 13.100Compliance w
4、ith a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2018.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN ISO 21904-3:2018EUROPEAN
5、STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 219043March 2018ICS 13.100; 25.160.01EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCENCENELEC Management Centre: Avenue Marnix 17, B1000 Brussels 2018 CEN Ref. No. EN ISO 21904-3:2018: EAll rights of exp
6、loitation in any form and by any means reserved worldwide for CEN national MembersHealth and safety in welding and allied processes - Requirements, testing and marking of equipment for air filtration - Part 3: Determination of the capture efficiency of on-torch welding fume extraction devices (ISO 2
7、1904-3:2018)Hygine et scurit en soudage et techniques connexes - Exigences, essais et marquage des quipements de filtration dair - Partie 3: Dtermination de lefficacit de captage des torches aspirantes (ISO 21904-3:2018)Arbeits- und Gesundheitsschutz beim Schweien und bei verwandten Verfahren - Anfo
8、rderungen, Prfung und Kennzeichnung von Luftreinigungssystemen - Teil 3: Bestimmung des Erfassungsgrades von brennerintegrierten Absaugeinrichtungen fr Schweirauch (ISO 21904-3:2018)This European Standard was approved by CEN on 1 March 2018.CEN members are bound to comply with the CEN/CENELEC Intern
9、al 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 CEN-CENELEC Management Centre or to any C
10、EN 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 CEN-CENELEC Management Centre has the same status as the official versi
11、ons.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Po
12、land, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.English VersionEN ISO 219043:2018 (E)European forewordThis document (EN ISO 21904-3:2018) has been prepared by Technical Committee ISO/TC 44 “Welding and allied processes“ in collaboration with
13、 Technical Committee CEN/TC 121 “Welding and allied processes”, 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 September 2018, and conflicting national sta
14、ndards shall be withdrawn at the latest by September 2018.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.According to the CEN-CENELEC Internal Regula
15、tions, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Ita
16、ly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.Endorsement noticeThe text of ISO 21904-3:2018 has been approved by CEN as EN ISO 21904-3:2018 without any modification.2BS
17、EN ISO 21904-3:2018ISO 219043:2018Foreword ivIntroduction v1 Scope .12 Normative references 13 Terms and definitions .14 Principle 25 Test equipment and materials .25.1 General requirement 25.2 Test equipment . 25.2.2 Isokinetic samplers. . 25.2.8 Equipment for measuring the mass of fume collected.
18、35.2.11 Device for measuring contact tip to workpiece distance (CTWD). 36 Test procedure 46.1 Preliminary tests . 46.1.1 Setting the shielding gas flow rate 46.1.2 Measuring the flow rates and determination of leakage . 46.1.3 Establishing the arcing time for total fume emission rate test 56.1.4 Set
19、ting up the test equipment 56.2 Capture efficiency tests 66.2.1 General66.2.2 Test procedure .66.2.3 Calculation of the results 77 Test parameters for generating capture efficiency data .88 Test report .9Annex A (informative) Equipment notes .10Annex B (normative) Trial tests .12Annex C (informative
20、) Examples of test chambers .14Annex D (normative) Test procedures.16Annex E (informative) Data processing for test method 3 17Annex F (normative) Test parameters form to be filled 19Annex G (informative) Information about the necessity to measure leakage 20Bibliography .21 ISO 2018 All rights reser
21、ved iiiContents PageBS EN ISO 21904-3:2018ISO 219043:2018ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees
22、. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the Intern
23、ational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the diff
24、erent types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shal
25、l not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is
26、 information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organiza
27、tion (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes, Subcommittee SC 9, Health and safety.A list of all parts in the ISO 21904 series can be found
28、 on the ISO website.Requests for official interpretations of any aspect of this document should be directed to the Secretariat of ISO/TC 44/SC 9 via your national standards body. A complete listing of these bodies can be found at www.iso.org.iv ISO 2018 All rights reservedBS EN ISO 21904-3:2018ISO 2
29、19043:2018IntroductionWelding generates fumes and gases which, if inhaled, can be harmful to human health. Therefore, control of the fume and gases needs to be exercised to minimize worker exposure.The most effective method of welding fume control is local exhaust ventilation (LEV) which captures th
30、e fumes at source before they enter the general environment and the breathing zone of workers.One form of LEV used in welding is on-torch extraction in which the extraction system is either an integral part of the welding torch or is attached to it close to the arc area. Anecdotal evidence within th
31、e fabrication industry suggested that it is impossible to capture fume efficiently while maintaining weld metal integrity but research (see Bibliography entry 6) has shown this not to be the case, certainly as far as weld metal porosity is concerned.It has been presumed in the drafting of this docum
32、ent that appropriately qualified and experienced people would execute its provisions and interpret the results obtained. ISO 2018 All rights reserved vBS EN ISO 21904-3:2018This page deliberately left blankHealth and safety in welding and allied processes Requirements, testing and marking of equipme
33、nt for air filtration Part 3: Determination of the capture efficiency of on-torch welding fume extraction devices1 ScopeThis document defines a laboratory method for measuring the welding fume capture efficiency of on-torch extraction systems. The procedure only prescribes a methodology, leaving sel
34、ection of the test parameters to the user, so that the effect of different variables can be evaluated.It is applicable to integrated on-torch systems and to systems where a discrete extraction system is attached to the welding torch close to the arc area. The methodology is suitable for use with all
35、 continuous wire welding processes, all material types and all welding parameters.The method can be used to evaluate the effects of variables such as extraction flow rate, extract nozzle position, shielding gas flow rate, welding geometry, welding torch angle, fume emission rate, etc., on capture ef
36、ficiency.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (i
37、ncluding any amendments) applies.ISO 15767, Workplace atmospheres Controlling and characterizing uncertainty in weighing collected aerosolsISO/IEC Guide 98 (all parts), Uncertainty of measurement3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO a
38、nd IEC maintain terminological databases for use in standardization at the following addresses: ISO Online browsing platform: available at https:/www.iso.org/obp IEC Electropedia: available at http:/www.electropedia.org/3.1test chambersemi-enclosed extracted chamber in which welding fume capture eff
39、iciency testing is performed3.2isokinetic samplerdevice for collecting aerosol samples at the same velocity as the air being sampledINTERNATIONAL STANDARD ISO 219043:2018 ISO 2018 All rights reserved 1BS EN ISO 21904-3:2018ISO 219043:20183.3test chamber sampling ductduct between the test chamber and
40、 an extraction fan in which all the fume generated can be collected or sampled isokinetically3.4emission ratemass of the particles emitted by the welding fume source per unit timeNote 1 to entry: The emission rate is expressed in mg/s.4 PrincipleAutomatic welding is performed using the on-torch extr
41、action torch under test, on a test piece, inside a continuously extracted test chamber. Testing is carried out using identical welding parameters with and without the on-torch extraction activated. The ratio of measurements in the test chamber sampling duct is used to calculate the capture efficienc
42、y of the on-torch extraction torch.Three methods of measuring the fume can be used. Two methods employ gravimetric measurement. The first method measures the total fume generated while second method employs isokinetic sampling in the test chamber sampling duct. The third method employs a direct read
43、ing measuring technique in the test chamber sampling duct.5 Test equipment and materials5.1 General requirementThe test setup shall enable containment of the fume generated in the arc area within the test chamber while ensuring the air velocity in the welding area below the torch does not exceed 0,2
44、 m/s without welding and with the on-torch extraction off. See also B.1.NOTE It is possible that not all of the fume generated by spatter production be contained within the test chamber.5.2 Test equipment5.2.1 Test chamber, constructed of materials that withstand close proximity to the heat and spat
45、ter generated by the welding or designed so that the materials used are sufficiently distant from the arc to avoid problems arising from heat and spatter generation. See Figures C.1 and C.2.Compliance with the requirements of 5.1 shall be verified.5.2.2 Isokinetic samplers. The sample flow rate shal
46、l be such that the velocity through the sample inlet is the same as the surrounding air velocity. This ensures that: the particle size distribution is not affected by the sampling process; and the sample represents the particles present in the sampling duct. See also B.2 and B.3.5.2.3 Total fume and
47、 isokinetic filters, manufactured from glass or quartz fibre, with particle retention properties down to approximately 1 m to 2 m. The filters shall not tear or perforate during testing (see A.2) and shall not be so friable that fibres can be lost from the filters during handling.2 ISO 2018 All righ
48、ts reservedBS EN ISO 21904-3:2018ISO 219043:2018Filters shall be treated according to the procedures defined in ISO 15767.5.2.4 Extraction fan, capable of maintaining a constant flow rate (2 %) in the test chamber sampling duct during testing when using during testing with isokinetic sampling or dir
49、ect reading equipment.The air flow generated by the fan shall be capable of retaining the entire fume generated within the test chamber (see A.3).5.2.5 Ontorch extraction unit, capable of maintaining a constant flow rate (2 %) in the on-torch extraction line during testing.5.2.6 Equipment for measuring welding current, welding voltage, wire feed speed and arcing time, capable of measuring the current, voltage, wire feed speed and arcing time within 1 %. Electronic integrating equipment with frequent sampling intervals and
