ISO INTERNATIONAL STANDARD 13966 First edition 1998-07-15 Thermoplastics pipes and fittings Nominal ring stiffnesses Tubes et raccords en matieres thermoplastiques Rigidite annulaire nominale ISO Reference number ISO 13966:1998(E) IHSunder Not for Resale ISO 13966:1998(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through isO a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non- governmental, in liaison with isO, also take part in the work. .ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids. @ISO1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International OrganizationforStandardization Case postale 56 . CH-1211 Geneve 20 · Switzerland Internet [email protected] Printed in Switzerland se from IHS Not for Resale INTERNATIONAL STANDARD @ISO ISO 13966:1998(E) Thermoplastics pipes and fittings Nominal ring stiffnesses Scope thermoplastics pipe systems having a circular cross-section. 2Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard.Atthetimeof publication,theeditionsindicatedwerevalid.All standardsaresubjectto revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 3:1973, Preferred numbers Series of preferred numbers IsO 9969:1994, Thermoplastics pipes Determination of ring stiffness. ISO13967:1998,Thermoplastics fittings—Determination of ring stiffness. 3 Definition For the purposes of this International Standard, the following definition applies. 3.1 nominal ring stiffness SN a numerical designation of the ring stiffness of a pipe or fitting, which is a convenient round number indicating the minimum required ring stiffness of the pipe or fitting NOTE - It is designated by the letters “SN" followed by the appropriate number. Nominal ring stiffnesses such that the selected value is less than or equal to the actual ring stiffness of the pipe or fitting as determined using the applicable method (see clause 5). If a nominal stiffness outside those covered by the table is required, the nominal ring stiffness shall be similarly selected from the R10 series as given in ISO 3. Copyright Inte ional Organization for Standardizatior