ISO 16422-2:2024

International
Standard
ISO 16422-2
First edition
Pipes and joints made of oriented
2024-02
unplasticized poly(vinyl chloride)
(PVC-O) for the conveyance of water
under pressure —
Part 2:
Pipes
Tubes et assemblages en poly(chlorure de vinyle) non plastifié
orienté (PVC-O) pour le transport de l'eau sous pression —
Partie 2: Tubes
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 4
5 Material. 5
5.1 General .5
5.2 Density .5
5.3 MRS class .6
5.4 Orientation factor .6
6 General characteristics . 6
6.1 Appearance .6
6.2 Colour .6
6.3 Opacity .6
6.4 Classification of pipes .7
6.4.1 Classification . .7
6.4.2 Calculation of wall thickness .7
7 Geometrical characteristics . 7
7.1 Measurement of dimensions .7
7.2 Length of pipes .7
7.3 Nominal outside diameters and wall thicknesses .7
7.4 Pipes with integral sockets with elastomeric sealing ring type .9
7.5 Plain ends .11
8 Selection of pipes .11
8.1 Selection of nominal pressure and pipe series S for water up to and including 25 °C .11
8.2 Determination of the allowable operating pressure for water up to 45 °C .11
9 Mechanical characteristics .11
9.1 Resistance to hydrostatic pressure .11
9.1.1 General .11
9.1.2 Pipes . 12
9.1.3 Pipes with integral sockets . 12
9.2 Impact strength . 12
9.3 Ring stiffness . 13
10 Physical characteristics .13
11 Sealing rings .13
12 Marking . . 14
12.1 General .14
12.2 Minimum required marking .14
12.3 Additional marking.14
Annex A (normative) Establishment of the pipe material classification .15
Annex B (normative) Minimum depth of engagement of sockets .18
Annex C (normative) Temperature derating factor .21
Annex D (informative) Calculation of negative pressure capability of pipes .22
Annex E (normative) Determination of axial and circumferential orientation factor .23
Bibliography .25

iii
Foreword
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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 16422-2, together with ISO 16422-1 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, ISO 16422-2 (this document)
and ISO 16422-5, with the following additions to ISO 16422-2:
— DN1200 values have been introduced;
— the tolerances of chamfers in plain ends have been modified;
— minimum values for orientation factors have been introduced;
— tolerances in density have been introduced;
— minimum length of engagement values have been introduced;
— the long-term test at 60ºC is performed on the pipe only;
— minimum hoop stress values for production control tests have been introduced;
— differential scanning calorimetry (DSC) has been identified as the preferred test method for gelation
in case of dispute.
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-
...