ISO INTERNATIONAL STANDARD 9969 Third edition 2016-01-15 Thermoplastics pipes Determination of ring stiffness Tubes en matieres thermoplastiques - Détermination de la rigidite annulaire Reference number ISO 9969:2016(E) ISO International Organization for Standardization @IS02016 vided by IHS under No reproduction or networking permitted without license from IHS IS0 9969:2016(E) COPYRIGHT PROTECTED DOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form 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 +41 22 749 09 47 copyright@iso.org www.iso.org Internatinir DrganizationforStandardization @ IS0 2016 - All rights reserved No reproduction or networking permited without license from IHS IS0 9969:2016(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references 3 Symbols. 4 Principle. 5 Apparatus. 6 Test pieces .3 6.1 Marking and number of test pieces .3 6.2 Length of test pieces 3 6.3 Inside diameter of test piece(s) .4 6.4 Age of test pieces. 7 Conditioning 8 Procedure ..5 9 Calculation of ring stiffness ..7 10 Test report ..8 iii se with ISt ed without license from IHS