Health and safety in welding and allied processes - Equipment for capture and separation of welding fume - Part 2: Requirements for testing and marking of separation efficiency (ISO 21904-2:2020)

EN-ISO 21904-2 specifies a method for testing equipment for the separation of welding fume in order to determine whether its separation efficiency meets specified requirements.The method specified does not apply to testing of filter cartridges independent of the equipment in which they are intended to be used.This document applies to equipment that is manufactured after its publication.

Arbeits- und Gesundheitsschutz beim Schweißen und bei verwandten Verfahren - Einrichtungen zum Erfassen und Abscheiden von Schweißrauch - Teil 2: Anforderungen an Prüfung des Abscheidegrades (ISO 21904-2:2020)

Dieses Dokument legt ein Verfahren für die Prüfung von Einrichtungen zum Abscheiden von Schweißrauch fest, um zu ermitteln, ob die Geräte die hinsichtlich der Abscheideleistung festgelegten Anforderungen erfüllen.
Das hier beschriebene Verfahren ist nicht anwendbar auf die Prüfung von Filterpatronen bzw. -kassetten, losgelöst von den Einrichtungen, in denen sie verwendet werden sollen.
Dieses Dokument gilt für Maschinen, die nach Veröffentlichung dieser Norm hergestellt wurden.
ANMERKUNG   In ISO 21904-1 sind allgemeine Belüftungssysteme vom Anwendungsbereich ausgenommen.

Hygiène et sécurité en soudage et techniques connexes - Équipements de captage et de filtration des fumées - Partie 2: Exigences relatives aux essais et marquage de l'efficacité de séparation (ISO 21904-2:2020)

Le présent document spécifie une méthode d'essai de l'équipement de filtration de fumées de soudage dans le but de déterminer si son efficacité de séparation satisfait aux exigences spécifiées.
La méthode spécifiée n'est pas applicable aux essais des cartouches filtrantes indépendantes de l'équipement dans lequel elles sont destinées à être utilisées.
Le présent document est applicable aux équipements fabriqués après sa date de publication.
NOTE       Les systèmes de ventilation générale sont exclus du domaine d'application de l'ISO 21904-1.

Zdravje in varnost pri varjenju in sorodnih postopkih - Oprema za zajem in ločevanje varilnega dima - 2. del: Zahteve za preskušanje in označevanje učinkovitosti ločevanja (ISO 21904-2:2020)

General Information

Status
Published
Public Enquiry End Date
04-Apr-2019
Publication Date
14-Apr-2020
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
31-Mar-2020
Due Date
05-Jun-2020
Completion Date
15-Apr-2020

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SLOVENSKI STANDARD
SIST EN ISO 21904-2:2020
01-maj-2020
Nadomešča:
SIST EN ISO 15012-1:2013
Zdravje in varnost pri varjenju in sorodnih postopkih - Oprema za zajem in
ločevanje varilnega dima - 2. del: Zahteve za preskušanje in označevanje
učinkovitosti ločevanja (ISO 21904-2:2020)
Health and safety in welding and allied processes - Equipment for capture and
separation of welding fume - Part 2: Requirements for testing and marking of separation
efficiency (ISO 21904-2:2020)
Arbeits- und Gesundheitsschutz beim Schweißen und bei verwandten Verfahren -
Einrichtungen zum Erfassen und Abscheiden von Schweißrauch - Teil 2: Anforderungen
an Prüfung des Abscheidegrades (ISO 21904-2:2020)
Hygiène et sécurité en soudage et techniques connexes - Équipements de captage et de
filtration des fumées - Partie 2: Exigences relatives aux essais et marquage de l'efficacité
de séparation (ISO 21904-2:2020)
Ta slovenski standard je istoveten z: EN ISO 21904-2:2020
ICS:
13.040.40 Emisije nepremičnih virov Stationary source emissions
13.100 Varnost pri delu. Industrijska Occupational safety.
higiena Industrial hygiene
25.160.30 Varilna oprema Welding equipment
SIST EN ISO 21904-2:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 21904-2:2020

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SIST EN ISO 21904-2:2020


EN ISO 21904-2
EUROPEAN STANDARD

NORME EUROPÉENNE

March 2020
EUROPÄISCHE NORM
ICS 25.160.01; 13.100 Supersedes EN ISO 15012-1:2013
English Version

Health and safety in welding and allied processes -
Equipment for capture and separation of welding fume -
Part 2: Requirements for testing and marking of
separation efficiency (ISO 21904-2:2020)
Hygiène et sécurité en soudage et techniques connexes Arbeits- und Gesundheitsschutz beim Schweißen und
- Équipements de captage et de filtration des fumées - bei verwandten Verfahren - Einrichtungen zum
Partie 2: Exigences relatives aux essais et marquage de Erfassen und Abscheiden von Schweißrauch - Teil 2:
l'efficacité de séparation (ISO 21904-2:2020) Anforderungen an Prüfung des Abscheidegrades (ISO
21904-2:2020)
This European Standard was approved by CEN on 20 January 2020.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21904-2:2020 E
worldwide for CEN national Members.

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SIST EN ISO 21904-2:2020
EN ISO 21904-2:2020 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------
SIST EN ISO 21904-2:2020
EN ISO 21904-2:2020 (E)
European foreword
This document (EN ISO 21904-2:2020) has been prepared by Technical Committee ISO/TC 44 "Welding
and allied processes" in collaboration with 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 2020, and conflicting national standards
shall be withdrawn at the latest by September 2020.
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.
This document supersedes EN ISO 15012-1:2013.
According to the CEN-CENELEC Internal Regulations, 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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 21904-2:2020 has been approved by CEN as EN ISO 21904-2:2020 without any
modification.


3

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SIST EN ISO 21904-2:2020

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SIST EN ISO 21904-2:2020
INTERNATIONAL ISO
STANDARD 21904-2
First edition
2020-02
Health and safety in welding and allied
processes — Equipment for capture
and separation of welding fume —
Part 2:
Requirements for testing and marking
of separation efficiency
Hygiène et sécurité en soudage et techniques connexes —
Équipements de captage et de filtration des fumées —
Partie 2: Exigences relatives aux essais et marquage de l'efficacité de
séparation
Reference number
ISO 21904-2:2020(E)
©
ISO 2020

---------------------- Page: 7 ----------------------
SIST EN ISO 21904-2:2020
ISO 21904-2:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 8 ----------------------
SIST EN ISO 21904-2:2020
ISO 21904-2:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Test method . 5
6.1 Selection of test arrangement . 5
6.2 Test conditions . 5
6.3 Procedure . 5
6.3.1 Source emission rate measurement . 5
6.3.2 Equipment without filter cleaning system . 5
6.3.3 Equipment with manually initiated filter cleaning system . 7
6.3.4 Equipment with automatically initiated filter cleaning system . 7
6.3.5 Equipment with electrostatic precipitators . 8
6.4 Calculation of the separation efficiency . 9
7 Accuracy of measurement . 9
8 Test report . 9
Annex A (informative) Test cabin .11
Annex B (informative) Welding fume source .12
Bibliography .14
© ISO 2020 – All rights reserved iii

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SIST EN ISO 21904-2:2020
ISO 21904-2:2020(E)

Foreword
ISO (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. 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 International 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
different 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 shall 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 information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see 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.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www. iso. org/members . html.
Official interpretations of ISO/TC 44 documents, where they exist, are available from this page:
https://committee. iso. org/sites/ tc 44/ home/interpretation . html.
A list of all parts in the ISO 21904 series can be found on the ISO website.
This first edition cancels and replaces ISO 15012-1.
iv © ISO 2020 – All rights reserved

---------------------- Page: 10 ----------------------
SIST EN ISO 21904-2:2020
ISO 21904-2:2020(E)

Introduction
It is common practice in the fabrication industry to control exposure to welding fume using local exhaust
ventilation equipment that, following capture and separation of the fume, returns the extracted air to
the workplace or exhausts it to the atmosphere. It is important that such equipment has high separation
efficiency so that as little fume as possible is recirculated or exhausted. This document has therefore
been developed to specify a test method for determining the efficiency of welding fume separation
equipment and the requirements of the test method.
© ISO 2020 – All rights reserved v

---------------------- Page: 11 ----------------------
SIST EN ISO 21904-2:2020

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SIST EN ISO 21904-2:2020
INTERNATIONAL STANDARD ISO 21904-2:2020(E)
Health and safety in welding and allied processes —
Equipment for capture and separation of welding fume —
Part 2:
Requirements for testing and marking of separation
efficiency
1 Scope
This document specifies a method for testing equipment for the separation of welding fume in order to
determine whether its separation efficiency meets specified requirements.
The method specified does not apply to testing of filter cartridges independent of the equipment in
which they are intended to be used.
This document applies to equipment that is manufactured after its publication.
NOTE General ventilation systems are excluded from the Scope of ISO 21904-1.
2 Normative references
The 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 (including any amendments) applies.
ISO 2602:1980, Statistical interpretation of test results — Estimation of the mean — Confidence interval
ISO 15011-1:2009, Health and safety in welding and allied processes — Laboratory method for sampling
fume and gases — Part 1: Determination of fume emission rate during arc welding and collection of fume
for analysis
ISO 21904-1:2020, Health and safety in welding and allied processes — Equipment for capture and
separation of welding fume — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21904-1 and the following apply.
ISO and 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/
3.1
free-standing unit
separation equipment with an integrated fan
3.2
modular system
separation equipment consisting of a scaleable filter system with the same filter elements and
conditions normally connected to a single fan
© ISO 2020 – All rights reserved 1

---------------------- Page: 13 ----------------------
SIST EN ISO 21904-2:2020
ISO 21904-2:2020(E)

3.3
welding fume source
source generating welding fume by welding process that charges separation equipment to perform
separation efficiency tests
3.4
emission rate
mass of the particles emitted by the welding fume source per time
Note 1 to entry: The emission rate is expressed in milligrams per second.
4 Principle
[10] [11]
The method is based on the methods specified in EN 1093-6 and EN 1093-7 . Under test, the
welding fume separation equipment is charged by welding fume generated by a welding process. The
welding fume concentrations are measured in the incoming and exhausted air of the separation unit.
The welding fume separation equipment under test is operated under defined conditions, according to
its intended use.
The emission rate of the welding fume source is measured separately. Therefore, the welding fume
generated by the source is sampled on preweighed filters over a period of time.
The air volume flow rate of the welding fume separation equipment and the testing time shall be
measured during the separation efficiency test. Emission rate, testing time and air volume flow rate
are used subsequently to calculate the concentration of welding fume in the incoming air. Welding
parameters should be the same when emission rate and separation efficiency test are performed.
Before separation efficiency measurements are made, all welding fume separation equipment are
charged for a period of 30 min using the welding fume source.
For equipment with filters that are not intended to be cleaned, the concentration of welding fume
passing through the separation equipment is measured subsequently for a period of 30 min and the
measured concentration is used, together with the welding fume concentration calculated from the
welding fume emission rate, to determine the separation efficiency.
For equipment with cleanable filters, an additional separation efficiency measurement is performed
after a further welding period without measurement and filter cleaning. The average of the two
separation efficiencies is calculated.
Two tests are performed and the average, the 95 % one-sided confidence interval and the lower
confidence limit value of the separation efficiency are calculated according to ISO 2602. If the resulting
lower confidence limit value is less than the required separation efficiency, consideration shall be given
to improve the filter unit design.
5 Apparatus
5.1 Welding fume source, capable of maintaining an emission rate of 10 mg/s ± 2 mg/s throughout
the test period.
The welding fume source shall be fitted with an extraction hood that retains all the welding fume
emitted and shall be designed in such a way that it can be connected to the inlet duct of the test cabin,
as described in Figure 1, or directly to welding fume separation equipment with a ducted outlet, as
described in Figure 2. It shall be possible to determine the welding fume emission rate in situ without
disturbing the welding set-
...

SLOVENSKI STANDARD
oSIST prEN ISO 21904-2:2019
01-marec-2019
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ORþHYDQMHYDULOQHJDGLPDGHO=DKWHYH]DSUHVNXãDQMHLQR]QDþHYDQMH
XþLQNRYLWRVWLORþHYDQMD ,62',6
Health and safety in welding and allied processes - Equipment for capture and
separation of welding fume - Part 2: Requirements for testing and marking of separation
efficiency (ISO/DIS 21904-2:2019)
Sicherheit und Gesundheitsschutz beim Schweißen und bei verwandten Verfahren -
Anforderungen, Prüfung und Kennzeichnung von Luftreinigungssystemen - Teil 2:
Anforderungen an Prüfung und Kennzeichnung des Abscheidegrades (ISO/DIS 21904-
2:2019)
Hygiène et sécurité en soudage et techniques connexes - Exigences, essais et
marquage des équipements de filtration d'air - Partie 2: Exigences relatives aux essais et
marquage de l'efficacité de séparation (ISO/DIS 21904-2:2019)
Ta slovenski standard je istoveten z: prEN ISO 21904-2
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
13.100 Varnost pri delu. Industrijska Occupational safety.
higiena Industrial hygiene
25.160.30 Varilna oprema Welding equipment
oSIST prEN ISO 21904-2:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 21904-2:2019

---------------------- Page: 2 ----------------------
oSIST prEN ISO 21904-2:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 21904-2
ISO/TC 44/SC 9 Secretariat: BSI
Voting begins on: Voting terminates on:
2019-01-29 2019-04-23
Health and safety in welding and allied processes —
Equipment for capture and separation of welding fume —
Part 2:
Requirements for testing and marking of separation
efficiency
ICS: 13.100; 25.160.01
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 21904-2:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019

---------------------- Page: 3 ----------------------
oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

---------------------- Page: 4 ----------------------
oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Equipment . 2
6 Test method . 5
6.1 Selection of test arrangement . 5
6.2 Test conditions . 5
6.3 Procedure . 5
6.3.1 Source emission rate measurement . 5
6.3.2 Equipment without filter cleaning system . 5
6.3.3 Equipment with manually initiated cleaning system . 7
6.3.4 Equipment with automatically initiated cleaning system . 7
6.3.5 Equipment with electrostatic precipitators . 8
6.4 Calculation of the separation efficiency . 9
7 Accuracy of measurement . 9
8 Test report . 9
Annex A (informative) Test cabin .10
Annex B (informative) Welding fume source .11
Bibliography .13
© ISO 2019 – All rights reserved iii

---------------------- Page: 5 ----------------------
oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

Foreword
ISO (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. 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 International 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
different 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 shall 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 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 ISO's adherence to the
World Trade Organization (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 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 2019 – All rights reserved

---------------------- Page: 6 ----------------------
oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

Introduction
It is common practice in the fabrication industry to control exposure to welding fume using local exhaust
ventilation equipment that, following capture and separation of the fume, returns the extracted air to
the workplace or exhausts it to the atmosphere. It is important that such equipment has high separation
efficiency so that as little fume as possible is recirculated or exhausted. This part of ISO 21904 has
therefore been promulgated to specify requirements and a test method for determining the efficiency
of welding fume separation equipment.
© ISO 2019 – All rights reserved v

---------------------- Page: 7 ----------------------
oSIST prEN ISO 21904-2:2019

---------------------- Page: 8 ----------------------
oSIST prEN ISO 21904-2:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 21904-2:2019(E)
Health and safety in welding and allied processes —
Equipment for capture and separation of welding fume —
Part 2:
Requirements for testing and marking of separation
efficiency
1 Scope
This part of ISO 21904 specifies a method for testing equipment for the separation of welding fume in
order to determine whether its separation efficiency meets specified requirements.
The method specified does not apply to testing of filter cartridges independent of the equipment in
which they are intended to be used.
This part of ISO 21904 applies to equipment that is manufactured after its publication.
2 Normative references
The 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 (including any amendments) applies.
ISO 2602, Statistical interpretation of test results — Estimation of the mean — Confidence interval
ISO 15011-1, Health and safety in welding and allied processes — Laboratory method for sampling fume
and gases — Part 1: Determination of fume emission rate during arc welding and collection of fume for
analysis
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21904-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1
free-standing unit
separation equipment with an integrated fan
3.2
modular system
separation equipment consisting of a scaleable filter system with the same filter elements and
conditions normally connected to a single fan
4 Principle
[10] [11]
The method is based on the methods specified in EN 1093-6 and EN 1093-7. Under test the
welding fume separation equipment is charged by welding fume generated by a welding process. The
© ISO 2019 – All rights reserved 1

---------------------- Page: 9 ----------------------
oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

welding fume concentration in the incoming and exhausted air of the separation unit is measured. The
welding fume separation equipment under test is operated under defined conditions, according to its
intended use.
The emission rate of the welding fume source is measured and used subsequently to calculate the
concentration of fume generated during a test period when separation efficiency is measured.
Before separation efficiency measurements are made, welding fume separation equipment is charged
for a period of 30 min using the welding fume source.
For equipment with filters that are not intended to be cleaned, the concentration of fume passing
through the separation equipment during a 30 min period is measured and used together with the fume
concentration calculated from the fume emission rate to determine the separation efficiency.
For equipment with cleanable filters, an additional separation efficiency measurement is performed
after a further welding period without measurement and filter cleaning. The average of the two
separation efficiencies is calculated.
Two tests are performed and the average, the 95 % one-sided confidence interval and the lower
confidence limit value of the separation efficiency are calculated according to ISO 2602. If the resulting
lower confidence limit value is less than the required separation efficiency, consideration shall be given
to improve the filter unit design.
5 Equipment
5.1 Welding fume source, capable of maintaining an emission rate of 10 mg/s ± 2 mg/s throughout
the test period. The welding fume source shall be fitted with an extracted fume hood that retains all the
fume emitted and shall be designed in such a way that it can be connected to the inlet duct of the test
cabin, as described in Figure 1, or directly to welding fume separation equipment with a ducted outlet,
as described in Figure 2. It shall be possible to determine the welding fume emission rate in situ without
disturbing the welding set-up in any way. An example of a suitable welding source and parameters
required to achieve the required welding fume emission rate are described in Annex B.
5.2 Test cabin, consisting of an enclosure for the welding fume separation equipment under test,
connected to the welding fume source via an upstream measurement duct. The cabin is connected to a
downstream measurement duct and an air mover (see Figure 1). The air flow rate through the air mover
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oSIST prEN ISO 21904-2:2019
ISO/DIS 21904-2:2019(E)

is adjusted to between 95 % and 100 % of the air flow rate in the upstream duct, thus ensuring a small
positive air pressure in the cabin.
Key
1 welding fume source (see Figure B.1)
2 welding fume separation equipment
3 test cabin
4 air mover
5 position for measuring the air flow rate in the upstream duct, q
V, 1
6 positions for measuring the air flow rate in the downstream duct, q and isokinetic sampling of welding
V, 2
fume in the downstream duct
7 damper (to control the air flow rate passing through the welding fume source in order to avoid shielding gas
disturbance)
8 damper (to ensure that all welding fume is captured, even when filter units with a low air flow rate are under test)
9 damper (to regulate the total air flow rate passing through the separation equipment)
10 damper (to control the air flow rate in the downstream duct in order to achieve a slight overpressure in the cabin)
11 gap with a flap (to prevent damage on the cabin in case of high overpressure)
d upstream duct diameter
1
d downstream duct diameter
2
Figure 1 — Example of test cabin (schematic layout)
The positions for measuring the air flow rate and isokinetic sampling of welding fume in the
downstream duct are not the same, but are shown thus in Figure 1 for convenience. The requirement is
that they comply with the dimensions marked in Figure
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