ISO 13956:2010

Plastics pipes and fittings - Decohesion test of polyethylene (PE) saddle fusion joints - Evaluation of ductility of fusion joint interface by tear test

ISO 13956:2010 specifies a method for the evaluation of the ductility of the fusion joint interface of assemblies of polyethylene (PE) pipe and electrofusion or heated tool saddles, intended for the conveyance of fluids.

Tubes et raccords en matières plastiques — Essai de décohésion des selles en polyéthylène (PE) assemblées par soudage — Évaluation de la ductilité de l'interface de soudage par essai d'arrachement

General Information

• Status: Published
• Publication Date: 21-Sep-2010
• ICS: 23.040.60 - Flanges, couplings and joints
• Technical Committee: ISO/TC 138/SC 5 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
• Drafting Committee: ISO/TC 138/SC 5 - General properties of pipes, fittings and valves of plastic materials and their accessories -- Test methods and basic specifications
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 07-Nov-2025
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 13956:2025 - Plastics pipes and fittings - Decohesion test of polyethylene (PE) saddle fusion joints - Evaluation of ductility of fusion joint interface by tear test
• Effective Date: 06-Jun-2022

Overview

ISO 13956:2010 specifies a standardized tear (decohesion) test to evaluate the ductility of the fusion joint interface between polyethylene (PE) pipes and electrofusion or heated-tool saddles used for fluid conveyance. The method characterizes failure modes at the fusion plane and quantifies percentage decohesion of the joint interface by measuring brittle fracture length and area after a controlled tensile or compressive separation.

Keywords: ISO 13956:2010, polyethylene (PE) saddle fusion joints, decohesion test, tear test, fusion joint ductility, electrofusion.

Key topics and requirements

• Scope: Test method for assemblies of PE pipe and electrofusion/heated-tool saddles.
• Principle: Apply load to separate the saddle from the pipe and evaluate the fusion interface for ductile vs. brittle failure.
• Test modes / equipment: Defined tensile modes (Type A1, A2), compression mode (Type B) and a Type C arrangement for larger fixtures. Loading pin diameter, clamping, and supporting frames are specified in the standard.
• Test speeds & conditioning: Typical speed (100 ± 10) mm/min; an alternative lower speed (25 ± 5) mm/min can be used if separation cannot be achieved. Conditioning: at least 24 h after jointing and test temperature conditioning at (23 ± 2) °C for ≥ 6 h.
• Sampling & preparation: Follow manufacturer instructions and ISO 11413 for electrofusion assembly preparation. Remove non-essential parts (e.g., branch outlet) and ensure minimum free pipe lengths around the saddle.
• Measurements & calculations: Measure maximum brittle fracture length l and overall fusion length y to calculate percentage decohesion L = (l / y) × 100. Measure brittle area A and compare to nominal fusion area A_nom to calculate A% = (A / A_nom) × 100.
• Acceptance guidance: Annex A recommends minimum values (each test piece): L ≥ 50% and A ≥ 25%.
• Reporting: Test report must cite ISO 13956:2010 and include component IDs, saddle size, pipe dimensions, fusion conditions, test mode, speed, temperature, number of pieces (normally three), failure types, decohesion percentages, observations and laboratory ID.

Applications

ISO 13956:2010 is used for:

• Quality control and batch testing of PE saddle fusion joints by manufacturers and production labs.
• Type testing and product development to confirm fusion joint ductility.
• Independent testing laboratories performing compliance and certification testing.
• Construction contractors, utilities and engineers verifying joint performance and investigating joint failures in gas and water distribution systems.

Practical benefits include objective measurement of fusion interface integrity, repeatable pass/fail criteria, and documentation to support regulatory or procurement requirements.

Related standards

• ISO 11413 - Preparation of test-piece assemblies between PE pipe and electrofusion fittings (normative reference).
• ISO 21751 - Strip-bend test for electrofusion assemblies (related/coordinating test method).

For specification or procurement, reference ISO 13956:2010 to ensure consistent evaluation of PE saddle fusion joint ductility.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 13956
First edition
2010-10-01
Plastics pipes and fittings — Decohesion
test of polyethylene (PE) saddle fusion
joints — Evaluation of ductility of fusion
joint interface by tear test
Tubes et raccords en matières plastiques — Essai de décohésion des
selles en polyéthylène (PE) assemblées par soudage — Évaluation de
la ductilité de l'interface de soudage par essai d'arrachement

Reference number
©
ISO 2010
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2010
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 either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2010 – All rights reserved

Contents Page
Foreword .iv
1 Scope.1
2 Normative references.1
3 Principle.1
4 Apparatus.1
4.1 General .1
4.2 Tensile test equipment — Type A1 or A2.1
4.3 Compressive equipment — Type B .3
4.4 Equipment — Type C .3
5 Sampling.4
5.1 Preparation of test pieces.4
5.2 Number of test pieces.5
6 Conditioning .5
7 Procedure.5
8 Test report.7
Annex A (informative) Recommended condition.9
Bibliography.10

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, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 13956 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 5, General properties of pipes, fittings and valves of plastic materials and
their accessories — Test methods and basic specifications.

iv © ISO 2010 – All rights reserved

INTERNATIONAL STANDARD ISO 13956:2010(E)

Plastics pipes and fittings — Decohesion test of polyethylene
(PE) saddle fusion joints — Evaluation of ductility of fusion
joint interface by tear test
1 Scope
This International Standard specifies a method for the evaluation of the ductility of the fusion joint interface of
assemblies of polyethylene (PE) pipe and electrofusion or heated tool saddles, intended for the conveyance of
fluids.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 11413, Plastics pipes and fittings — Preparation of test piece assemblies between a polyethylene (PE)
pipe and an electrofusion fitting
3 Principle
A load is applied to the saddle of an assembly of an electrofusion or heated tool saddle fused on to a pipe.
The ductility of the fusion joint interface is characterized by the appearance of the failure in the fusion plane
and by the determination of the percentage of decohesion.
4 Apparatus
4.1 General
The test apparatus shall comprise a tensile equipment type A1 or A2, as indicated in Figures 1 and 2
respectively, or a compressive equipment type B as indicated in Figure 3. For nominal outside pipe diameter
W 250 mm, equipment type C as indicated in Figure 4 may be used.
4.2 Tensile test equipment — Type A1 or A2
The tensile equipment shall include the following main parts.
4.2.1 Tensile testing machine, capable of maintaining a speed of (100 ± 10) mm/min, with sufficient force
to separate the saddle from the pipe.
4.2.2 Loading pin, with an outside diameter of at least 1/2 of the nominal outside diameter of the pipe and
allowing rotation.
4.2.3 Appropriate clamping device, to grip the saddle and allow separation from the pipe.
NOTE The type A1 clamping device allows symmetrical loading of the saddle from both sides (an example is shown
in Figure 1). The type A2 cl
...