ISO INTERNATIONAL STANDARD 13957 First edition 1997-12-15 Plastics pipes and fittings -- Polyethylene (PE) tapping tees -- Test method for impact resistance Tubes et raccords en matieres plastiques - Prises de branchement en polyethylene (PE) -- Methode d'essai de la résistance au choc This material is reproduced from Iso documents under International Organization for Standardization (Iso) Copyright License number IHS/IcC/1996. Not for resale. No part of these ISo documents may be reproduced in any fom, electronic retrieval system or otherwise, except as allowed in the copyright law of the country of use, or with the prior written consent of ISO (Case postale 56, 1211 Geneva 20, Switzerland, Fax +41 22 7341079),IHs orthe ISo Licensor'smembers. ISO Reference number ISO 13957:1997(E) ernational Organization for Standardization with ISO No reproduction or networking permited without license from IHS Not for Resale ISO 13957:1997(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 technical committees. Each member body interested in a subject for which 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, atso 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. International Standard ISO 13957 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fitings and valves for the transport of fluids, Subcommittee s SC 5, General properties of pipes, fitings and valves of plastic materials and their accessories Test methods and basic specifications. @ISO1997 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56: CH-1211 Geneve 20 Switzerland internet [email protected] X.400 C=ch;a=400net;p=iso; 0=isocs; S=centra Printed in Switzerland ii al Organization for Standardizatior No reproduction or networking permited without license from IHS Not fr Resale ISO 13957:1997(E) INTERNATIONALSTANDARD CISO Plastics pipes and fittings - Polyethylene (PE) tapping tees - Test method for impact resistance Scope This International Standard specifies a test method for the impact resistance of polyethylene (PE) tappingtees. This International Standard is applicable to PE tapping tees intended for the conveyance of fluids. 2 Principle The cap (or the top of the branch) of a tapping tee is subjected to impact by means of a weight, falling from a constant height, parallel to the axis of the pipe to which the tapping tee is fused. After two impacts from opposite directions parallel to the axis of the pipe, the tee is inspected for visible damage and for loss of airtightness. Thetestiscarried outat oC ±2C or anotherspecified temperature. 3 Apparatus 3.1 Falling-weight test machine, incorporating a main frame with guide bars or a guide tube fixed in the vertical position to guide a striker so that, when the striker is released, it falls vertically and freely and the velocity of the striker at the moment of impact with the tapping tee is not less than 95 % of the theoretical velocity. 3.2Striker, with a mass of 2500g±20g or 5000 g±20 g and witha hemispherical strikingsurface of diameter 50 mm. 3.3Rigid test piece holder with a steel mandrel, capable of maintaining the test piece in the position indicated in figure 1 and preventing any rotation of the test piece during the t