ISO 16422-2:2024

Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the conveyance of water under pressure - Part 2: Pipes

This document specifies the 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 wastewater and irrigation under pressure. It also specifies the test parameters for the test methods referred to in this document. In conjunction with ISO 16422-1 and ISO 16422-5, this document is applicable to oriented PVC-O pipes, with or without integral socket, 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 Figure C.1. The piping system according to this document is intended for the conveyance of cold water up to pressures of 25 bar[1] and especially in those applications where special performance requirements are needed, such as impact loads and pressure fluctuations, up to pressure of 25 bar. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2

Tubes et assemblages en poly(chlorure de vinyle) non plastifié orienté (PVC-O) pour le transport de l'eau sous pression — Partie 2: Tubes

General Information

• Status: Published
• Publication Date: 31-Jan-2024
• ICS: 23.040.20 - Plastics pipes
• ICS: 23.040.45 - Plastics fittings
• ICS: 91.140.60 - Water supply systems
• Technical Committee: ISO/TC 138/SC 2 - Plastics pipes and fittings for water supplies
• Drafting Committee: ISO/TC 138/SC 2 - Plastics pipes and fittings for water supplies
• Current Stage: 6060 - International Standard published
• Start Date: 01-Feb-2024
• Due Date: 28-Sep-2023
• Completion Date: 01-Feb-2024

Relations

• Revises: ISO 16422:2014 - Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the conveyance of water under pressure - Specifications
• Effective Date: 28-Oct-2023

Overview

ISO 16422-2:2024 specifies requirements for solid‑wall pipes made of oriented unplasticized poly(vinyl chloride) (PVC‑O) intended for the conveyance of water under pressure. This Part 2 (Pipes) covers pipes used underground or above ground (where protected from direct sunlight) for water supply, buried drainage, sewerage, treated wastewater and irrigation. The standard defines material, dimensional, mechanical and physical characteristics, and the test parameters for referenced methods. It is intended for cold water up to and including 25 °C (and components up to 45 °C) and for pressures up to 25 bar. ISO 16422-2 is to be used alongside ISO 16422-1 (general requirements) and ISO 16422-5 (fitness for purpose).

Key topics and requirements

• Material and classification: Requirements for PVC‑O material, density tolerances and MRS (Minimum Required Strength) classes; orientation factors and test methods for axial/circumferential orientation are described.
• Geometrical characteristics: Measurement of dimensions, nominal outside diameters, wall thickness calculation, pipe lengths, plain ends and pipes with integral sockets.
• Mechanical characteristics: Resistance to hydrostatic pressure (long‑term performance), impact strength, ring stiffness and production control tests (including minimum hoop stress values).
• Physical and thermal limits: Temperature derating (see Annex C) and guidance for use between 25 °C and 45 °C; negative pressure capability calculation (informative).
• Sealing and joints: Requirements for integral sockets with elastomeric sealing rings and minimum engagement depths (Annex B).
• Marking and traceability: Minimum and optional marking information for identification and conformity.
• Test methods and annexes: Test parameters and normative annexes covering material classification, orientation factor determination and test conditions (including preference for DSC for gelation disputes).

Keywords: ISO 16422-2, PVC-O pipes, oriented PVC, hydrostatic pressure, impact strength, ring stiffness, piping standards.

Applications and who uses it

• Water utilities and municipal engineers specifying water mains, service lines and irrigation systems.
• Pipe manufacturers designing and certifying PVC‑O pipes and production control processes.
• Civil and mechanical engineers involved in pressurized drainage, sewerage and treated wastewater systems.
• Test laboratories and conformity assessors performing long‑term pressure, impact and orientation tests.
• Procurement and regulatory bodies requiring standardized performance and traceability for pressurized water piping.

Related standards

• ISO 16422‑1 (General)
• ISO 16422‑5 (Fitness for purpose)
• ISO 1167‑1/2 (Hydrostatic pressure test methods)
• ISO 161‑1 (Nominal diameters and pressures)
• ISO 2505 (Longitudinal reversion)
• ISO 1452‑3 / EN 12842 (other pipe materials and components)

For specification or implementation, consult the full ISO 16422‑2:2024 text and complementary parts of the ISO 16422 series.

Standards Content (Sample)

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
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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
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)
patent(s) which may be required to implement this document. However, implementers are cautioned that
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 16422-2, 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-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 pipe 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.
The ISO 16422 series, of which this is Part 2, specifies the requirements for a piping system made from
oriented unplasticized poly(vinyl chloride) (PVC-O) and its components. The piping system is intended to be
used for water supply, pressurized drainage and sewerage and irrigation systems to be used underground
or above ground where protected to direct sunlight.
Requirements and test methods for PVC-O components are specified in in this document, as well as in
ISO 16422-1 and ISO/TS 16422-3. For other components (not manufactured from PVC-O), reference is made
to the following documents: ISO 1452-3 (PVC-U) and EN 12842 (Cast Iron). Characteristics for fitness for
purpose (mainly for joints) are established in ISO 16422-5.

v
International Standard ISO 16422-2:2024(en)
Pipes and joints made of oriented unplasticized poly(vinyl
chloride) (PVC-O) for the conveyance of water under
pressure —
Part 2:
Pipes
1 Scope
This document specifies the 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 wastewater and irrigation under
pressure. It also specifies the test parameters for the test methods referred to in this document.
In conjunction with ISO 16422-1 and ISO 16422-5, this document is applicable to oriented PVC-O pipes, with
or without integral socket, 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 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 dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 16422-1, Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) — Part 1: General
ISO 16422-5, Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) — Part 5: Fitness for
purpose of the system
ISO 161-1, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal pressures
— Part 1: Metric series
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm

ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 1: General method
ISO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 2505, Thermoplastics pipes — Longitudinal reversion — Test method and parameters
ISO 2507-1, Thermoplastics pipes and fittings — Vicat softening temperature — Part 1: General test method
ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions
ISO 3127, Thermoplastics pipes — Determination of resistance to external blows — Round-the-clock method
ISO 4065, Thermoplastics pipes — Universal wall thickness table
ISO 4633, Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for
materials
ISO 6259-2, Thermoplastics pipes — Determination of tensile properties — Part 2: Pipes made of unplasticized
poly(vinyl chloride) (PVC-U), oriented unplasticized poly(vinyl chloride) (PVC-O), chlorinated poly(vinyl chloride)
(PVC-C) and high-impact poly(vinyl chloride) (PVC-HI)
ISO 7686, Plastics pipes and fittings — Determination of opacity
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
ISO 9852, Unplasticized poly(vinyl chloride) (PVC-U) pipes — Dichloromethane resistance at specified
temperature (DCMT) — Test method
ISO 9969, Thermoplastics pipes — Determination of ring stiffness
ISO 11922-1:1997, Thermoplastics pipes for the conveyance of fluids — Dimensions and tolerances — Part 1:
Metric series
ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification, designation
and design coefficient
ISO 18373-1, Rigid PVC pipes — Differential scanning calorimetry (DSC) method — Part 1: Measurement of the
processing temperature
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16422-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
nominal length
minimum length which does not include the depth of the socketed portions
Note 1 to entry: See Figure 1.

Key
l nominal length of the pipe
Figure 1 — Points of measurement for nominal lengths
3.2
nominal size DN
numerical designation of the size of a component, other than a component designated by thread size, which
is a convenient round number approximately equal to the manufacturing dimension in millimetres (mm)
3.3
out-of-roundness
ovality
difference between the measured maximum and the measured minimum outside diameter in the same
cross-section of a pipe or spigot, or the difference between the measured maximum and the measured
minimum inside diameter in the same cross-section of a socket
3.4
Poisson contraction
shortening of the length of the pipe when pressurized
3.5
temperature contraction
shortening of the length of the pipe due to drop in temperature
3.6
angular deflection
retraction of one side of the spigot due to angular deflection of the spigot within the socket
3.7
tolerance
permitted variation of the specified value of a quantity, expressed as the difference between the permitted
maximum and the permitted minimum value

3.8
long-term hydrostatic strength for 50 years at 20 °C
σ
LPL20°C,50years
quantity with the unit of stress, i.e. MPa, which can be considered to be a property of the material under
consideration
Note 1 to entry: This represents the 97,5 % lower confidence limit for the long-term hydrostatic strength and equals
the predicted average strength at a temperature of 20 °C and for a time of 50 years with internal water pressure.
3.9
working pressure
maximum pressure which a piping system can sustain in continuous use under given service conditions
4 Symbols
a start of sealing area in the socket
b end of cylindrical part of socket and pipe
C overall service design coefficient
D measured outside diameter before conditioning (orientation factor test)
em
D measured outside diameter after conditioning (orientation factor test)
i
d external diameter (at any point)
e
d inside diameter of the socket
i
d mean inside diameter of the socket
im
d nominal (outside or inside) diameter
n
E Young’s modulus
E elastic modulus in the circumferential direction (2,0 GPa)
c
e wall thickness (at any point)
e mean wall thickness before conditioning (orientation factor test)
em
e mean wall thickness after conditioning (orientation factor test)
i
e minimum wall thickness
min
e nominal wall thickness
n
I moment of inertia of a pipe = e /12
n
L length of pipe in metres
L measured length before conditioning (orientation factor test)
o
L measured length after conditioning (orientation factor test)
i
l nominal length of the pipe
l length of the socket
s
m depth of engagement
m minimum depth of engagement due to angular deflection of the pipe
a
m minimum depth of engagement calculated
calc
m lower limit of the minimum depth of engagement
min
m minimum depth of engagement due to the Poisson contraction
p
m minimum depth of engagement due to safety allowance
s
m minimum depth of engagement due to temperature contraction
T
P unsupported critical buckling pressure, in kilopascals
cr
R radius of the striker nose
S calculated preferred value of the nominal S series number of the pipe according to ISO
calc
4065:2018, Table 2
S calculated initial ring stiffness
Ncalc
−5 −1
α coefficient of linear expansion, (7 × 10 ) °C
β angle chamfer
ΔT temperature differential
θ maximum angle of deflection of spigot within the socket
λ coefficient of axial orientation
ai
λ coefficient of circumferential orientation
ci
μ Poisson ratio (0,40)
ρ density
σ hydrostatic stress in the circumferential direction
σ long-term hydrostatic strength for 50 years at 20 °C
LPL20°C,50years
σ design stress
s
5 Material
5.1 General
The material from which the pipes are made shall conform to ISO 16422-1 and to the requirements given in
5.2 and 5.4.
5.2 Density
The density, ρ, at 23 °C of the pipe, when measured in accordance with ISO 1183-1, shall be within the
following limits:
3 3
1 350 kg/m < ρ < 1 460 kg/m
5.3 MRS class
Oriented pipes made from a defined PVC compound/formulation and with a well-defined orientation level
in circumferential and axial direction, shall be evaluated according to the procedures of Annex A. The MRS
(minimum required strength) value shall be classified in accordance with ISO 16422-1.
The MRS class shall be declared by the manufacturer.
5.4 Orientation factor
The level of orientation is an indirect parameter for the material classification of the pipes and is dependent
on the production process.
The circumferential and axial orientation factors shall be declared by the manufacturer and shall conform
to the minimum values as defined in Table 1.
The orientation factors shall be measured according to Annex E and specified by the manufacturer to be
within ± % deviation from the declared values.
Table 1 — Minimum declared orientation factor
Dimensions in MPa
Minimum required strength
31,5 35,5 40,0 45,0 50,0
(MRS)
Axial 1,0
Circumferential 1,5 1,6 1,7 1,8 1,9
6 General characteristics
6.1 Appearance
When viewed without magnification, the internal and external surfaces of pipes shall be smooth, clean and
free from scoring, cavities and other surface defects to an extent that would prevent conformity to this
document. The material shall not contain any impurities visible without magnification. The ends of the pipe
shall be cut cleanly and square to the axis of the pipe.
6.2 Colour
The colour of the pipes shall be uniform throughout the wall.
The preferred colour of pipes shall be as follows:
a) for water supply cream, blue, white or white with blue stripes;
b) for irrigation under pressure blue, white or white with blue stripes;
c) for pressurized drainage and sewerage grey, brown or white with brown stripes;
d) for treated waste water, purple.
NOTE The colouring of pipes for the supply of water for human consumption can be subject to national regulations.
6.3 Opacity
If a pipe is required to be opaque for use in above-ground applications, the wall of the pipe shall transmit not
more than 0,2 % of visible light falling on it when tested in accordance with ISO 7686.

6.4 Classification of pipes
6.4.1 Classification
Pipes shall be classified to their nominal pressure, PN.
The nominal pressure, PN, the pipe series, S, and the design stress, σ , are connected by the relationship
s
described in Formulae (1) to (4):
10σ
s
PN≅ (1)
S
SDR−1
S= (2)
d
n
SDR= (3)
e
n
MRS
σ = (4)
s
C
6.4.2 Calculation of wall thickness
The relationship between the nominal wall thickness, e , and the nominal outside diameter d is specified in
n n
ISO 4065. The values for nominal pipe wall thickness, e , for nominal pressure ratings, PN, can be calculated
n
by substituting the values for d and S as shown in Formula (5):
n calc
d
n
e = (5)
n
21S +
calc
Values shall be rounded to one decimal place according to the rules of ISO 4065.
Nominal S numbers and their calculated values are given in ISO 4065 for the R10 series of preferred numbers.
For the R20 series required for this document, refer to ISO 3.
The nominal outside diameter and nominal wall thickness for the relevant nominal pressure and material
classes are specified in Table 2.
7 Geometrical characteristics
7.1 Measurement of dimensions
The dimensions of pipes shall be measured in accordance with ISO 3126.
7.2 Length of pipes
It is recommended that pipes be supplied in one or more of the following lengths: 6 m, 10 m, 12 m, where
these lengths do not include the depth of any (integral) socket(s). Other lengths are subject to agreement
between the manufacturer and the purchaser.
The nominal length of the pipe shall not be less than that specif
...