ISO 18851:2015

INTERNATIONAL ISO
STANDARD 18851
First edition
2015-03-15
Plastics piping systems — Glass-
reinforced thermosetting plastics
(GRP) pipes and fittings — Test method
to prove the structural design of fittings
Systèmes de canalisation en matières plastiques — Tubes et raccords
plastiques thermodurcissables renforcés de verre (PRV) — Méthode
d’essai pour prouver la conception structurelle des raccords
Reference number
ISO 18851:2015(E)
©
ISO 2015

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ISO 18851:2015(E)

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ii © ISO 2015 – All rights reserved

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ISO 18851:2015(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Terms and definitions . 1
3 Principle . 1
4 Apparatus . 2
4.1 End sealing devices . 2
4.1.1 General. 2
4.1.2 Capable of applying the end loads . 2
4.1.3 Not capable of applying the end loads . 2
4.2 Supports . 2
4.2.1 End thrust supports . 2
4.2.2 Straps and Cradles . 2
4.3 Source of hydrostatic pressure . 2
4.4 Means to measure the gauge pressure . 2
5 Test pieces . 2
5.1 Test arrangement . 2
5.2 Number of test pieces . 3
6 Conditioning . 4
7 Test temperature . 4
8 Procedure. 4
8.1 Tests to be performed . 4
8.2 Test Failure Criteria . 4
8.2.1 Bursting . 4
8.2.2 Leaking . 4
8.2.3 Weeping . 4
8.3 Initial leakage . 4
8.4 Resistance to internal pressure . 5
9 Test report . 5
Bibliography . 7
© ISO 2015 – All rights reserved iii

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ISO 18851:2015(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, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
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assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 6, Reinforced plastics pipes and fittings for all applications.
iv © ISO 2015 – All rights reserved

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INTERNATIONAL STANDARD ISO 18851:2015(E)
Plastics piping systems — Glass-reinforced thermosetting
plastics (GRP) pipes and fittings — Test method to prove
the structural design of fittings
1 Scope
This International Standard specifies methods of test for fittings of any form, i.e. bends, branches, tapers,
intended to be used in plastics piping systems for pressure and non-pressure drainage and sewerage or water
supply made of glass-reinforced thermosetting plastics (GRP). This International Standard is applicable to
fittings, in order to test their structural design, but is not applicable to connecting joint systems. It assumes
that the fitting either is or is not intended to be subject to the effects of hydrostatic end thrust.
The tests detailed in 8.1 to 8.4 are applicable to fittings intended to be used in buried or non-buried
applications.
These test procedures are applicable to fittings of all nominal sizes specified in the referring standard.
The tests are for evaluating fittings intended for use in applications conveying liquids at temperatures
specified in the referring standards.
The test procedures in this International Standard are damaging to the test piece which will
...