ISO INTERNATIONAL STANDARD 5175-2 First edition 2017-09 Gas welding equipment - Safety devices - Part 2: Devices not incorporating a flame (flashback) arrestor Matériel de soudage au gaz - Dispositifs de sécurité - Partie2:Dispositifs sans arretdeflamme Reference number IS0 5175-2:2017(E) ISO @ IS0 2017 IS05175-2:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS02017,PublishedinSwitzerland All rights reserved. Unless otherwise specified, 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 Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax+41227490947 [email protected] www.iso.org ii @ IS0 2017 - All rights reserved IS0 5175-2:2017(E) Contents Page Foreword iv 1 Scope 1 2 Normative references 3 Terms and definitions 4 Design and materials. 4.1 Connections 4.2 Materials... 5 Requirements 5.1 General. 5.2 Gastightness 5.3 Pressure resistance. 5.4 Non-return valve, 5.5 Pressure relief valves. 5.6 Excess flow cut-off valves 5.7 Flashback resistance. 6 Methods for type testing. 6.1 General. 6.2 Accuracy of pressure and flow measurements 6.3 Testgases.. 6.4 Gas tightness test 6.5 Pressure resistance test. 6.6 Non-return valve test. 6.7 Pressurereliefvalves 6.8 Excess flow cut-off valve. 6.9 Internal leakage test for cut-off valves 7 Manufacturer's instructions. 8 Marking. Annex A (informative) Gas flow measurement. Annex B (informative) Third party testing information [1 @ IS0 2017 - All rights reserved ii