ISO 16422-1:2024

International
Standard
ISO 16422-1
First edition
Pipes and joints made of oriented
2024-02
unplasticized poly(vinyl chloride)
(PVC-O) for the conveyance of water
under pressure —
Part 1:
General
Tubes et assemblages en poly(chlorure de vinyle) non plastifié
orienté (PVC-O) pour le transport de l'eau sous pression —
Partie 1: Généralités
Reference number
© ISO 2024
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Terms related to wall construction.2
3.2 Terms related to geometrics .2
3.3 Terms related to material .3
3.4 Terms related to material characteristics .3
3.5 Terms related to service conditions .4
4 Symbols and abbreviated terms. 5
4.1 Symbols .5
4.2 Abbreviated terms .6
5 Material. 6
5.1 General requirements for compounds or formulations .6
5.2 Special requirements for compounds or formulations for components in contact with
drinking water .6
5.3 Use of reworked material .6
6 Material classification. 7
6.1 MRS value classification pipes.7
6.2 PN classification fittings .7
6.3 Design stress pipes .7
Bibliography . 8

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 2, Plastics pipes and fittings for water supplies.
This first edition of ISO 16422-1, together with ISO 16422-2 and ISO 16422-5, cancels and replaces the second
edition of ISO 16422:2014, which has been technically revised.
The main changes are as follows:
— ISO 16422:2014 has been split into several parts, under the general title “Pipes and joints made of oriented
unplasticized poly(vinyl chloride) (PVC-O) for the conveyance of water under pressure”. The information
previously included in ISO 16422:2014 has been divided into ISO 16422-1 (this document), ISO 16422-2
and ISO 16422-5.
A list of all parts in the ISO 16422 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Molecular orientation of thermoplastics results in the improvement of physical and mechanical properties.
Orientation is carried out at temperatures well above the glass transition temperature.
Orientation of PVC-U pipe-material can be induced by different processes.
In general, the following production process is common.
— A thick-wall tube is extruded (feedstock) and conditioned at the desired temperature.
— The orientation process is activated primarily in circumferential direction under controlled conditions.
Axial orientation can also be activated in the product.
— After the orientation process, the pipe is cooled down quickly to ambient temperature.
The orientation of the molecules creates a laminar structure in the material of the pipe wall. This structure
gives the ability to withstand brittle failure emanating from minor flaws in the material matrix or from
scratches at the surface of the pipe wall.
Improved hoop strength allows reduced wall thickness with material and energy savings. It also results in
improved resistance to impact and fatigue.
The classification of the material depends on material compound/formulation and stretch ratios used.
Therefore, with the classification, these characteristics may be specified or determined.
Regarding potential adverse effects on the quality of water intended for human consumption caused by
the products covered by this document, this document provides no information as to whether or not the
products can be used without restriction.
Requirements and test methods for PVC-O components are specified in this document, as well as in
ISO 16422-2 and ISO/TS 16422-3.

v
International Standard ISO 16422-1:2024(en)
Pipes and joints made of oriented unplasticized poly(vinyl
chloride) (PVC-O) for the conveyance of water under
pressure —
Part 1:
General
1 Scope
This document specifies the general characteristics of solid-wall pipes made of oriented unplasticized
poly(vinyl chloride) (PVC-O) for piping systems intended to be used underground or above-ground (where
protected from direct sunlight), for water supply, buried drainage, sewerage, treated waste water and
irrigation under pressure.
In conjunction with ISO 16422-2, ISO/TS 16422-3, ISO 16422-5 and ISO 1452-4, this document is applicable
to PVC-O pipes and PVC-O fittings, as well as to valves, their joints and to joints with components of other
plastics and non-plastics materials intended to be used for the following:
a) water mains and services lines;
b) conveyance of water for both outside and inside buildings;
c) drainage, sewerage and treated wastewater under pressure;
d) irrigation under pressure.
This document is applicable to piping systems intended for the supply of water under pressure up to and
including 25 °C (cold water), intended for human consumption and for general purposes as well as for
wastewater under pressure.
This document is also applicable to components for the conveyance of water and wastewater up to and
including 45 °C. For temperatures between 25 °C and 45 °C, see ISO 16422-2:2023, Figure C.1.
The piping system according to this document is intended for the conveyance of cold water up to pressures
1)
of 25 bar and especially in those applications where special performance requirements are needed, such as
impact loads and pressure fluctuations, up to pressure of 25 bar.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For
...