ISO/TS 16422-3:2023

Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the conveyance of water under pressure - Part 3: Fittings

This document specifies the characteristics of solid-wall oriented unplasticized poly(vinyl chloride) (PVC-O) fittings 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. This document is applicable to double sockets, repair couplings, reducers and to non-end load bearing elbows only. This document is not applicable to tees, flange adaptors, etc. NOTE For double sockets, repair couplings, and reducers, there are no special fittings designs for end-load bearing applications. However, restrained gaskets can be used for end-load bearing applications. In this case, the requirements of ISO 16422-5 are applicable. This document 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 an 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 ISO 16422-2, Figure C.1. The piping system according to this document is intended for the conveyance of cold water up to pressure 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 3: Raccords

General Information

• Status: Published
• Publication Date: 26-Jun-2023
• 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: 27-Jun-2023
• Due Date: 28-Sep-2023
• Completion Date: 27-Jun-2023

Overview

ISO/TS 16422-3:2023 - "Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC‑O) for the conveyance of water under pressure - Part 3: Fittings" specifies the characteristics and test parameters for solid‑wall oriented PVC‑O fittings. It covers double sockets, repair couplings, reducers and non‑end load bearing elbows intended for buried or protected above‑ground water, drainage, sewerage, treated wastewater and irrigation systems. The document is intended to be used alongside ISO 16422‑1 and ISO 16422‑5 for full system requirements.

Key topics and technical requirements

• Scope and applicability
  • Fittings for PVC‑O piping systems for water under pressure (cold water up to and including 25 °C; components up to 45 °C).
  • Design pressures up to 25 bar; includes considerations for impact loads and pressure fluctuations.
  • Excludes tees, flange adaptors and end‑load bearing fittings (restrained gaskets and ISO 16422‑5 apply for end‑load solutions).
• Material and orientation
  • Requirements for oriented unplasticized PVC (PVC‑O) material, including density and circumferential orientation factor.
  • Background on molecular orientation: improved hoop strength, impact and fatigue resistance through controlled stretching of PVC‑U preforms.
• Geometrical and physical characteristics
  • Design lengths, bend radii, nominal outside diameters, wall thickness and opacity/colour requirements.
  • Specific guidance for fittings with integral sockets and elastomeric sealing rings.
• Mechanical and performance testing
  • Test parameters and methods for resistance to hydrostatic pressure, long‑term hydrostatic strength (Annex A), and determination of orientation (Annex B).
  • Requirements for sealing rings and joint performance.
• Marking and documentation
  • Minimum and additional marking requirements to ensure traceability and correct use.

Practical applications

ISO/TS 16422-3:2023 is applicable to:

• Water mains and service lines
• Building water supply (internal and external)
• Pressurized drainage, sewerage and treated wastewater systems
• Irrigation under pressure

It is suited for projects where improved mechanical performance (reduced wall thickness, higher hoop strength, impact resistance) of PVC‑O fittings is desired.

Who should use this standard

• PVC‑O fittings manufacturers and product developers
• Water utility engineers and pipeline designers
• Specifiers, procurement teams and standards compliance officers
• Test laboratories, certification bodies and installers

Related standards

• ISO 16422‑1 (General)
• ISO 16422‑2 (Pipes - dimensional and temperature guidance)
• ISO 16422‑5 (Fitness for purpose - restrained gaskets and end‑load bearing requirements)
• Referenced test standards such as ISO 1167, ISO 9080 and ISO 3126 for pressure and dimensional tests.

Keywords: ISO/TS 16422-3:2023, PVC‑O fittings, oriented PVC‑O, fittings for water under pressure, double sockets, repair couplings, reducers, hydrostatic strength.

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 16422-3
First edition
2023-06
Pipes and joints made of oriented
unplasticized poly(vinyl chloride)
(PVC-O) for the conveyance of water
under pressure —
Part 3:
Fittings
Tubes et assemblages en poly(chlorure de vinyle) non plastifié orienté
(PVC-O) pour le transport de l'eau sous pression —
Partie 3: Raccords
Reference number
© ISO 2023
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 . 3
5 Material. 5
5.1 General . 5
5.2 Density . 5
5.3 Orientation factor . 5
6 General characteristics . 5
6.1 Appearance . 5
6.2 Colour . 5
6.3 Opacity . 6
6.4 Classification of fittings . . 6
7 Geometrical characteristics . 6
7.1 Design lengths, bend radii and angles . 6
7.2 Measurement of dimensions . 6
7.3 Nominal outside diameters and wall thickness . 6
7.4 Fittings with integral sockets with elastomeric sealing ring type . 6
8 Pressure and operating temperature . 7
8.1 Selection of nominal pressure for water up to and including 25 °C . 7
8.2 Determination of the allowable operating pressure for water up to 45 °C . 7
9 Mechanical characteristics — Resistance to hydrostatic pressure .7
10 Physical characteristics .7
11 Sealing rings .8
12 Performance requirements . .8
13 Marking . . 8
13.1 General . 8
13.2 Minimum required marking . . 8
13.3 Additional marking. 9
Annex A (normative) Determination of long-term hydrostatic strength .10
Annex B (normative) Determination of circumferential orientation factor .12
Annex C (informative) Recommended dimensions of PVC-O fittings .14
Bibliography .19
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 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.
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.
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 in circumferential and
axial directions under controlled conditions.
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. Improved
resistance to impact and fatigue also result.
The classification depends on the material compound/formulation and stretch ratios used. Therefore,
with the classification, these characteristics can be specified or determined.
The ISO 16422 series, of which this document is Part 3, 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.
In respect of potential adverse effects on the quality of water intended for human consumption, caused
by the products covered by this document, the following points are relevant:
— this document provides no information as to whether or not the products can be used without
restriction;
— requirements and test methods for PVC-O material and components, other than fittings, are specified
in ISO 16422-1 and ISO 16422-2. 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 specified in ISO 16422-5.
The future documents ISO 16422-1, ISO 16422-2 and ISO 16422-5 are intended to cancel and replace
ISO 16422:2014.
This document is a completely new part of the ISO 16422 series since PCV-O fittings were not included
in ISO 16422:2014.
This document is specifically focussed on fittings, as opposed to more general specifications, which are
now covered in the various other parts of the ISO 16422 series.
v
TECHNICAL SPECIFICATION ISO/TS 16422-3:2023(E)
Pipes and joints made of oriented unplasticized poly(vinyl
chloride) (PVC-O) for the conveyance of water under
pressure —
Part 3:
Fittings
1 Scope
This document specifies the characteristics of solid-wall oriented unplasticized poly(vinyl chloride)
(PVC-O) fittings 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. This document is applicable to double sockets, repair couplings, reducers and to non-
end load bearing elbows only. This document is not applicable to tees, flange adaptors, etc.
NOTE For double sockets, repair couplings, and reducers, there are no special fittings designs for end-load
bearing applications. However, restrained gaskets can be used for end-load bearing applications. In this case, the
requirements of ISO 16422-5 are applicable.
This document 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 an 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 ISO 16422-2, Figure C.1.
The piping system according to this document is intended for the conveyance of cold water up to
1)
pressure 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.
2)
ISO 16422-1:— , Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the
conveyance of water under pressure — Part 1: General
5 2
1) 1 bar =0,1 MPa=10 Pa; 1 MPa= 1 N/mm .
2) Under preparation. Stage at the time of publication: ISO/DIS 16422-1:2023.
3)
ISO 16422-2:— , Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the
conveyance of water under pressure — Part 2: Pipes
4)
ISO 16422-5:— , Pipes and joints made of oriented unplasticized poly(vinyl chloride) (PVC-O) for the
conveyance of water under pressure — 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
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 1167-3, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
the resistance to internal pressure — Part 3: Preparation of components
ISO 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: Immersion
method, liquid pycnometer method and titration method
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 4633, Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for
materials
ISO 6259-1, Thermoplastics pipes — Determination of tensile properties — Part 1: General test method
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 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 terminology 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) Under preparation. Stage at the time of publication: ISO/DIS 16422-2:2023.
4) Under preparation. Stage at the time of publication: ISO/DIS 16422-5:2023.
3.1
PVC-O fitting
fitting of oriented unplasticized poly(vinyl chloride) (PVC-O) made from stretching PVC-U preforms
under certain conditions which improve its mechanical behaviour
Note 1 to entry: This means that fittings made from different components are excluded from the scope of this
document.
3.2
laying length socketed outlet
Z-length
distance from the inserted tube or spigot end to the intersection point of the fitting/valve axis (fitting
or valve centre)
[SOURCE: ISO 1452-3:2009, 3.1.1]
3.3
laying length spigot outlet
Z-length
distance from the outlet end to the intersection point of the fitting/valve axis (fitting or valve centre)
[SOURCE: ISO 1452-3:2009, 3.1.2]
3.4
laying length socket with parallel outlets
Z-length
distance between the ends of the inserted tubes or spigots
[SOURCE: ISO 1452-3:2009, 3.1.3]
3.5
laying length one socket and one spigot with parallel outlets
Z-length
distance from the inserted tube or spigot end to the end of the spigot outlet
[SOURCE: ISO 1452-3:2009, 3.1.4]
3.6
design length of bends
Z-length
length of an outlet, excluding any socket length or insert length of spigot
[SOURCE: ISO 1452-3:2009, 3.1.5]
3.7
lower confidence limit of the predicted hydrostatic pressure
p
LPL
quantity with the dimension of pressure, which represents the 97,5 % (one sided) lower confidence
4 Symbols
C overall service design coefficient
D measured outside diameter before testing
e,meas,1
D measured outside diameter after testing
e,meas.2
d outside diameter (at any point)
e
d mean outside diameter
em
d inside diameter (at any point)
i
d mean inside diameter of socket
im
d nominal (outside or inside) diameter
n
e wall thickness (at any point)
e mean wall thickness
m
e mean wall thickness before testing
m,1
e mean wall thickness after testing
m,2
e nominal wall thickness
n
f derating (or uprating) factor for application
A
f derating factor for temperatures
T
K K-value
l length of socket
s
l maximum length of socket
s,max
l minimum length of spigot
1,min
m minimum depth of engagement
min
MRP minimum required pressure capability of the fitting is the value of the p at 20 °C for 50
LPL
years rounded to the nearest 0,01 bar
PFA allowable operating pressure
PN nominal pressure
p internal hydrostatic pressure
p test pressure
T
r bend radius
r minimum bend radius
min
S calculated preferred value of the nominal S series number of the pipe from according to
calc
ISO 4065:2019, Table 2
Z design length connecting part double socket
c
Z minimum design length connecting part double socket
c,min
Z design laying length
d
Z minimum design laying length
,d,min
Z design length reducing part
r
Z minimum design length reducing part
r,min
α bend angle
β minimum angle chamfer
λ axial orientation factor
a
λ circumferential ori
...