1、June 2008DEUTSCHE NORM English price group 9No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 13.040.40; 25.160.01; 25.1
2、60.10!$PFw“1453584www.din.deDDIN EN ISO 15012-2Health and safety in welding and allied processes Requirements, testing and marking of equipment for air filtration Part 2: Determination of the minimum air volume flow rate of captorhoods and nozzles (ISO 15012-2:2008)English version of DIN EN ISO 1501
3、2-2:2008-06Sicherheit und Gesundheitsschutz beim Schweien und bei verwandten Verfahren Anforderungen, Prfung und Kennzeichnung von Luftreinigungssystemen Teil 2: Bestimmen des Mindestluftvolumenstroms von Absaughauben und Flanschplatten(ISO 15012-2:2008)Englische Fassung DIN EN ISO 15012-2:2008-06ww
4、w.beuth.deDocument comprises 13 pagesDIN EN ISO 15012-2:2008-06 2 National foreword This standard has been prepared by Technical Committee CEN/TC 121 “Welding” (Secretariat: DIN, Germany), Subcommittee SC 9 “Health and safety in welding and allied processes”, in collaboration with Technical Committe
5、e ISO/TC 44 “Welding and allied processes”, Subcommittee SC 9 “Health and safety”. The DIN Standards corresponding to the International Standards referred to in clause 2 of this document are as follows: ISO 12100-1 DIN EN ISO 12100-1 ISO 12100-2 DIN EN ISO 12100-2 DIN EN ISO 15012 consists of the fo
6、llowing parts, under the general title Health and safety in welding and allied processes Requirements, testing and marking of equipment for air filtration: Part 1: Testing of the separation efficiency for welding fume Part 2: Determination of the minimum air volume flow rate of captor hoods and nozz
7、les The following part is under preparation: Part 3: Determination of the capture efficiency of welding fume extraction devices using tracer gas National Annex NA (informative) Bibliography DIN EN ISO 12100-1, Safety of machinery Basic concepts, general principles for design Part 1: Basic terminolog
8、y, methodology DIN EN ISO 12100-2, Safety of machinery Basic concepts, general principles for design Part 2: Technical principles The responsible German body involved in its preparation was the Normenausschuss Schweitechnik (Welding Standards Committee), Technical Committee NA 092-00-09 AA Arbeits-
9、und Gesundheitsschutz beim Schweien und verwandte Verfahren. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 15012-2April 2008ICS 25.160.30English VersionHealth and safety in welding and allied processes -Requirements, testing and marking of equipment for air filtration -Part 2: Determination
10、of the minimum air volume flow rate ofcaptor hoods and nozzles (ISO 15012-2:2008)Hygine et scurit en soudage et techniques connexes -Exigences, essais et marquage des quipements defiltration dair - Partie 2: Dtermination du dbit volumiqueminimal dair des bouches de captage (ISO 15012-2:2008)Sicherhe
11、it und Gesundheitsschutz beim Schweien und beiverwandten Verfahren - Anforderungen, Prfung undKennzeichnung von Luftreinigungssystemen - Teil 2:Bestimmen des Mindestluftvolumenstroms vonAbsaughauben und Flanschplatten (ISO 15012-2:2008)This European Standard was approved by CEN on 21 March 2008.CEN
12、members are bound to comply with the CEN/CENELEC Internal Regulations 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 applica
13、tion to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has t
14、he same status as theofficial versions.CEN members are the national 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
15、,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reserv
16、edworldwide for CEN national Members.Ref. No. EN ISO 15012-2:2008: EEN ISO 15012-2:2008 (E) Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .6 4 Principle8 5 Requirement.8 6 Equipment 8 7 Test method8 7.1 Test conditions 8 7.2 Position of the measur
17、ement plane.8 7.2.1 Hoods and nozzles with an aspect ratio of less than or equal to 48 7.2.2 Hoods and nozzles with an aspect ratio of greater than 4 9 7.3 Measurement points9 7.4 Procedure .9 8 Marking .9 9 Test report 10 Bibliography 11 2 DIN EN ISO 15012-2:2008-06 EN ISO 15012-2:2008 (E) Foreword
18、 This document (EN ISO 15012-2:2008) has been prepared by Technical Committee CEN/TC 121 “Welding”, the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 44 “Welding and allied processes”. This European Standard shall be given the status of a national standard, ei
19、ther by publication of an identical text or by endorsement, at the latest by October 2008, and conflicting national standards shall be withdrawn at the latest by October 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN an
20、d/or CENELEC shall not be held responsible for identifying any or all such patent rights. 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, Cyprus, Czech Republ
21、ic, 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 the United Kingdom. 3 DIN EN ISO 15012-2:2008-06 EN ISO 15012-2:2008 (E)
22、Introduction Welding and allied processes generate fume and gases, which, if inhaled, can be harmful to human health. Control is often required to maintain exposure at acceptable levels and this can be achieved by capturing the fume and gases using local exhaust ventilation (LEV), which consists of
23、a capture device, such as a captor hood or nozzle, connected, via ducting, to an exhaust system. The plume of welding fume rises at a velocity of about 0,3 m/s and the air draughts commonly encountered in workshops are of the same order and can be higher. Effective capture of welding fume and gases
24、can only be achieved when the extracted air velocity at the emission point exceeds the resulting velocity of the draught and the plume, so a velocity of 0,4 m/s has been selected for testing. For a particular capture device, this capture velocity can only be achieved by applying a minimum air volume
25、 flow rate, which is dependent upon the aspect ratio, the cross-sectional area of the device and its distance from the emission point. Consequently, capture devices need to be used with exhaust systems that provide, at least, the minimum air volume flow rate. The design of capture devices can be ver
26、y different. Aspect ratios range from those applicable to circular hoods to those of slots, so the size and shape of the area (capture zone) where fume and gases are captured, while using the minimum air volume flow rate, also varies considerably. Therefore, this part of ISO 15012 requires manufactu
27、rers of capture devices to measure the minimum air volume flow rate at measurement points selected to give an estimate of the size and shape of the capture zone. 4 DIN EN ISO 15012-2:2008-06 EN ISO 15012-2:2008 (E) 1 Scope This part of ISO 15012 specifies a method for establishing the minimum air vo
28、lume flow rate required for captor hoods and nozzles to effectively capture fume and gases from welding and allied processes. The method can be used with capture devices of any aspect ratio and cross-sectional area, but it is not applicable to on-gun extraction systems and down draught tables. This
29、part of ISO 15012 also specifies the test data to be marked on the capture devices. 2 Normative 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 th
30、e referenced document (including any amendments) applies. ISO 12100-1, Safety of machinery Basic concepts, general principles for design Part 1: Basic terminology, methodology ISO 12100-2, Safety of machinery Basic concepts, general principles for design Part 2: Technical principles 5 DIN EN ISO 150
31、12-2:2008-06 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12100-1 and ISO 12100-2 and the following apply. 3.1 capture device equipment for capturing welding fume at source See Figure 1. Key 1 entry plane (cross-sectional area for capture devices
32、without flange) 2 nozzle 3 duct 4 nozzle with flange 5 cross-sectional area of a flanged capture device ( W 30) 6 hood 7 hood with flange angle between entry plane and nozzle/hood angle between entry plane and flange Figure 1 Entry plane and cross-sectional area of different designs of capture devic
33、e 3.2 capture zone three-dimensional space in front of the entry plane of a capture device in which the air velocity is greater than or equal to the minimum air velocity required for effective capture of welding fume 3.3 entry plan outermost area of a capture device 3.4 cross-sectional area area of
34、the opening of a capture device in the entry plane (for a nozzle or hood without a flange), or, area of a capture device in the plane in which the flange is attached, excluding the area of any obstructions in the entry plane (for a nozzle or hood with a flange) See Figure 1. 3.5 aspect ratio ratio o
35、f the lengths, x and y, in the entry plane, with x1W y1See Figure 2. NOTE The aspect ratio is 1 for a circular device and greater than 1 for other shapes. EN ISO 15012-2:2008 (E) 6 DIN EN ISO 15012-2:2008-06 Key x0, y0, z0centre point of the entry plane and origin for the measurement point co-ordina
36、tes x1length of the entry plane of the capture device in the x-direction (x1W y1) y1length of the entry plane of the capture device in the y-direction (x1W y1) Figure 2 Schematic layout for a capture device 3.6 measurement plane plane, parallel to the entry plane, in which measurements of air veloci
37、ty are made See Figure 1. 3.7 nozzle capture device with an angle, , smaller than 60 between the side of the device and the entry plane See Figure 1. 3.8 flange surface extending outwards from, and almost parallel to ( 30), the entry plane of a capture device, providing a barrier to unwanted air flo
38、w from behind See Figure 1. 3.9 hood capture device with an angle, , greater than or equal to 60 between the side of the device and the entry plane See Figure 1. 3.10 minimum air volume flow rate air volume flow rate required for effective capture of welding fume NOTE The minimum air volume flow rat
39、e depends on the type and the geometric dimensions of the capture device and the test positions selected to demonstrate the extent of the capture zone (see 7.2). EN ISO 15012-2:2008 (E) 7 DIN EN ISO 15012-2:2008-06 4 Principle Tests are performed to determine the air volume flow rate required to ach
40、ieve an air velocity of 0,4 m/s at a minimum of two measurements points in front of the capture device on a measurement plane parallel to the entry plane of the capture device. Three tests are performed at each measurement point with air volume flow rates that provide approximate velocities of 0,3 m
41、/s, 0,4 m/s and 0,5 m/s. The air volume flow rate that provides a velocity of exactly 0,4 m/s at each measurement point is calculated from linear regression of the results. The minimum air volume flow rate of the capture device is taken to be the highest of the values obtained at the different measu
42、rement points. NOTE The minimum air volume flow rate is determined in this manner because it is difficult to set an air volume flow rate that gives an air velocity of exactly 0,4 m/s at a given measurement point. 5 Requirement The manufacturer of a hood or nozzle shall use the results of these tests
43、 to specify and mark the device with the minimum air volume flow rate required to achieve an air velocity of 0,4 m/s in the measurement plane, the distance of the measurement plane from the entry plane and the position of the measurement points selected to demonstrate the extent of the capture zone
44、of the device. The measurement points shall be identified by their (x, y)-co-ordinates projected from the entry plane. NOTE A hood or nozzle is expected to achieve effective capture of welding fume if it is operated with an air volume flow rate greater than or equal to the determined minimum air vol
45、ume flow rate and, in addition, if it is positioned at a distance less than or equal to the distance between the measurement plane and the entry plane of the device. 6 Equipment 6.1 Anemometer, suitable for measuring air velocities in the range 0,3 m/s to 0,5 m/s with a maximum uncertainty of 0,02 m
46、/s, with a response time less than or equal to 1 s and having a calibration that is traceable to national standards. 6.2 Flow meter, or other suitable device, capable of measuring air volume flow rate with a maximum uncertainty of 5 % and having a calibration that is traceable to national standards.
47、 6.3 Measure, suitable for measuring distances with an uncertainty of 1 mm. 7 Test method 7.1 Test conditions Position the hood or nozzle so that it is free standing and sited away from any obstructions. Take care to minimise the influence of any disturbing air draughts. 7.2 Position of the measurem
48、ent plane 7.2.1 Hoods and nozzles with an aspect ratio of less than or equal to 4 Determine the required distance, zi, in centimetres, between the measurement plane and the entry plane of the hood or nozzle of the capture device using Equation (1): zi= A + 7,5 (1) where A is the cross-sectional area
49、, in centimetres squared, of the hood or nozzle. EN ISO 15012-2:2008 (E) 8 DIN EN ISO 15012-2:2008-06 7.2.2 Hoods and nozzles with an aspect ratio of greater than 4 Determine the required distance, zi, in centimetres, between the measurement plane and the entry plane of the hood or nozzle of the capture device using Equation (2): zi= (A/4) + 10 (2) where A is the cross-sectional area, in centimetres squared, of the hood or nozzle. 7.3 Measurement points Select a minimum of two points on the measurement plane (see 7.2)
