ISO INTERNATIONAL STANDARD 20602 First edition 2019-05 Ships and marine technology Check valves for use in low temperature applications - Design and testing requirements Navires et technologie maritime - Clapets de retenue destinés aux applications a basse temperature - Exigences de conception et d'essai Reference number IS0 20602:2019(E) so @ IS0 2019 IS0 20602:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ 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: +4122 749 0111 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 20602:2019(E) Contents Page Foreword ..V 1 Scope .1 2 Normative references 3 Terms and definitions 4 Pressure temperature rating 4.1 Types of fluids.. ..3 4.2 Working pressure and designed temperature 5 Design .3 5.1 General structure of a check valve .3 5.2 Materials General. 5.3 Body. 4 5.3.1 Materials ..4 5.3.2 Manufacturing 4 5.4 Cover (bonnet) ..5 5.4.1 Types. 5 5.4.2 Materials 5 5.5 Disc. 5 5.5.1 Types .5 5.5.2 Materials ..5 5.6 Gasket. .5 5.7 Valve Seat .5 5.7.1 Types .5 5.7.2 Materials .6 5.8 Hinges and hinge pin (as applicable) .6 5.8.1 Types .6 5.8.2 Materials .6 5.9 Bolts and nuts .6 5.9.1 Types. 5.9.2 Materials ..6 6 Surface treatment ..6 7 Welding and heat treatment .6 7.1 Welding. .6 7.2 Heat treatment ..6 8 Test and inspection .6 8.1 Materialtest 8.2 Non-destructive inspection. .7 8.2.1 Radiographic testing (RT) 8.2.2 Penetrant testing (PT) 7 8.2.3 Ultrasonic testing (UT) .8 8.2.4 Retest. .8 8.2.5 Reporting test result .8 8.3 Dimension check .8 8.4 Visual inspection .8 8.5 Heat treatment inspection ..8 8.6 Pressuretests .8 8.7 Fire safety test 8.8 Cryogenic tests. .9 8.8.1 Test scope. ..9 8.8.2 Test procedure ..9 8.8.3 Submission of test result .10 9 Marking .11 IS0 2019 - All rights reserved iii