ISO INTERNATIONAL STANDARD 19970 First edition 2017-06 Refrigerated hydrocarbon and non petroleum based liquefied gaseous fuels Metering of gas as fuel on LNG carriers during cargo transfer operations Hydrocarbures réfrigérés et combustibles gazeux liquefiés a base non peétroliere - Mesurage du gaz comme carburant sur les transporteurs de GNL pendant les opération de transfert de cargaison Reference number IS0 19970:2017(E) [so International Organization for Standardization @ IS0 2017 IS0 19970:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, Published in Switzerland 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. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org Intenationaibr PrganizationforStandardization icensee-ZHEJIANG INST OF STANDARDIZRoISQ s1.7 - All rights reserved Not for Resale, 2017/8/21 01:04:51 etworking permitted without license from IHS IS0 19970:2017(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions ..1 4 Design requirements. 4.1 General. .3 4.2 Flowmeter .3 4.3 Indicating device .3 5 Accuracy requirement .3 6 Calibration and accuracy verification .4 6.1 General. ..4 6.2 Calibration at laboratory or factory .4 6.3 Calibration and accuracy verification of indicating devices after installation ..4 6.4 Periodic accuracy verification of indicating devices 4 7 Metering and calculation .5 7.1 General 7.2 Metering. 5 7.3 Calculation of heating value .5 Annex A (informative) Typical installation of fuel gas flowmeters 7 Annex B (informative) Application of the energy of BOG consumed by LNG carriers to custody transfer measurement .8 Bibliography 9 iii =ZHEJIANG INSTOF STANDARDIZATION C15956617 vided by IHS under thout license from IHS