ISO INTERNATIONAL STANDARD 18154 First edition 2017-03 Ships and marine technology - Safety valve for cargo tanks of LNG carriers - Design and testing requirements Navires et technologie maritime - Soupape de surete pour les réservoirs de cargaison des méthaniers - Exigences de conception etd'essai Reference number IS0 18154:2017(E) [so International Organization for Standardization @ IS0 2017 ZHEJIANG INSTOFSTANDARDIZATION C15956617 ed without license from IHS IS0 18154:2017(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+412274909 47 copyright@iso.org www.iso.org Intenationai br PrganizationforStandardization icensee-ZHEJIANG INST OF STANDARDIZRoISQ s1.7 - All rights reserved Not for Resale, 2017/5/16 00:38:52 etworking permitted without license from IHS IS0 18154:2017(E) Contents Page Foreword ..V 1 Scope .1 2 Normative references ..1 3 Terms and definitions 4 Main valve components .2 4.1 Body. .2 4.2 Nozzle. 4.3 Disk. 2 4.4 Cover. .2 4.5 Diaphragm .2 5 Design ..3 6 Materials ..4 7 Production testing and inspection ..4 7.1 Purpose.. ..4 7.2 Impacttest. 4 7.3 Non-destructive inspection .4 7.4 Pressure test. .5 7.4.1 General requirement .5 7.4.2 Fluid .5 7.4.3 Duration .5 7.4.4 Test equipment. 5 7.5 Surface inspection.. .5 7.6 Visual inspection .5 8 Performance test. .6 8.1 Performance test in ambient temperature .6 8.1.1 Purpose. 8.1.2 Number of test times. .6 8.1.3 Fluid ..6 8.1.4 Acceptancecriteria .6 8.2 Leakage test in ambient temperature ..6 8.2.1 Purpose .6 8.2.2 Fluid .6 8.2.3 Test pressure ..6 8.2.4 Duration. .6 8.2.5 Acceptance leakage rate 8.2.6 Test equipment. .7 8.3 Performance test in low temperature 8.3.1 Purpose 7 8.3.2 Number of test times. .7 8.3.3 Fluid. 7 8.3.4 Acceptance criteria. .7 8.4 Preparation for the performance test in low temperature 7 8.4.1 Start temperature for the test. .7 8.4.2 Safety requirement... ..7 8.4.3 Test system .7 8.5 Leakage test in low temperature 8.5.1 Purpose 8.5.2 Fluid ..8 8.5.3 Test pressure. ..8 8.5.4 Duration. ..8 8.5.5 Acceptance tolerance. .9 8.5.6 Test equipment. 9 iii ISee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 d without license from IHS