ISO/TS 23818-3:2026

Technical
Specification
ISO/TS 23818-3
Second edition
Assessment of conformity of
2026-02
plastics piping systems for
the rehabilitation of existing
pipelines —
Part 3:
Unplasticised poly(vinyl chloride)
(PVC-U) material
Évaluation de la conformité des systèmes de canalisations en
plastique destinés à la réhabilitation des réseaux existants —
Partie 3: Matériau poly(chlorure de vinyle) non-plastifié (PVC-U)
Reference number
© ISO 2026
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: +41 22 749 01 11
Email: copyright@iso.org
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 . 1
3.1 Assessment of conformity .1
3.2 Rehabilitation, general .5
4 Abbreviated terms . 5
5 General . 6
6 Testing and inspection . 6
6.1 Grouping .6
6.1.1 General .6
6.1.2 Size groups .6
6.1.3 Fitting groups .7
6.2 Type testing .7
6.3 Batch release tests .7
6.4 Process verification tests .7
6.5 Audit tests .8
6.6 Indirect tests .8
6.7 Test records .8
Annex A (normative) Test procedures for plastics piping systems for the rehabilitation of
networks for underground non-pressure drains and sewers . 9
Annex B (normative) Specification of new system (N), change in design (D), change in material
(M) and extension of the product range (E) . 14
Annex C (informative) Summary tables of scheme requirements .16
Bibliography . 17

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 ISO/TC 138 Plastics pipes, fittings and valves for the transport of fluids,
Subcommittee SC 8, Rehabilitation of pipeline systems, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 155, Plastics piping systems and ducting systems, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO/TS 23818-3:2021), which has been technically
revised.
The main changes are as follows:
— the document has been amended following the merging and renumbering of International Standards
concerning piping systems, referred to in this document;
— in Clause 3, seven definitions have been removed by reference to ISO 11295;
— lining with spirally-wound pipes has been excluded and has been incorporated in ISO/TS 23818-4.
A list of all parts in the ISO/TS 23818 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
International Standards dealing with the following applications are either available or in preparation for
pipeline rehabilitation:
— ISO 11300: Piping systems for rehabilitation of underground drains, sewers and water supply networks;
— ISO 11301: Piping systems for rehabilitation of underground gas supply networks.
These International Standards are distinguished from those for conventionally installed plastics piping
systems by the requirement to verify certain characteristics in the as-installed condition, after site
processing. This is in addition to specifying requirements for plastics piping system components as
manufactured.
For the assessment of conformity, five technical specifications for pipe systems of distinctive materials are
applicable:
— ISO/TS 23818-1;
— ISO/TS 23818-2;
— ISO/TS 23818-3 (this document);
— ISO/TS 23818-4.
These technical specifications cover the International Standards concerning piping systems, as presented in
Table 1.
Table 1 — Structure of technical specifications for assessment of conformity
Application
Drains, sewers
Technical
Material Technique
and Gas supply
Specification
water supply networks
networks
Lining with continuous pipes and close fit pipes trenchless
ISO/TS 23818-1 PE replacement using pipe bursting, pipe extraction, horizontal ISO 11300-1 ISO 11301-1
drilling and impact moling
Thermoset com-
ISO/TS 23818-2 Lining with cured-in-place pipes (CIPP) ISO 11300-2 n/a
posite
ISO/TS 23818-3 PVC-U Lining with close-fit pipes ISO 11300-3 n/a
Thermoplastic Lining with spirally wound pipes and rigidly anchored plastic
a
ISO/TS 23818-4 ISO 11300-4 n/a
composite liners (RAPL)
b b b
— PA-U — n/a —
a
In preparation
b
Under development (as ISO/TS 23818-5)
The format of the four technical specifications is in line with technical specifications for assessment of
conformity to other system standards, apart from presenting the detailed requirements for inspection
and testing in two annexes, for non-pressure applications and pressure applications (where applicable),
respectively.
For this document, covering only non-pressure applications, the format is schematically represented in
Figure 1.
v
Figure 1 — Format of the technical specifications for conformity assessment
Figures 2 and 3 are intended to provide general information on the concept of testing and organization
of those tests used for the purpose of the assessment of conformity. For each type of test, i.e. type testing
(TT), batch release test (BRT), process verification test (PVT), and audit test (AT), this document details the
applicable characteristics to be assessed as well as the frequency and sampling of testing.
A typical scheme for the assessment of conformity of PVC-U pipes, fittings, joints or assemblies by
manufacturers is given in Figure 2.
Figure 2 — Typical scheme for the assessment of conformity by a manufacturer
A typical scheme for the assessment of conformity of PVC-U pipes, fittings, joints or assemblies by
manufacturers, including certification, is given in Figure 3.

vi
Figure 3 — Typical scheme for the assessment of conformity by a manufacturer, including
certification
vii
Technical Specification ISO/TS 23818-3:2026(en)
Assessment of conformity of plastics piping systems for the
rehabilitation of existing pipelines —
Part 3:
Unplasticised poly(vinyl chloride) (PVC-U) material
1 Scope
This document provides a scheme for the assessment of conformity of PVC-U products and assemblies for
the rehabilitation of existing pipelines, in accordance with ISO 11300-3, and intended to be included in
the manufacturer’s quality plan as part of the quality management system and for the establishment of
certification procedures.
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 1628-2, Plastics — Determination of the viscosity of polymers in dilute solution using capillary viscometers
— Part 2: Poly(vinyl chloride) resins
ISO 4435:2003, Plastics piping systems for non-pressure underground drainage and sewerage — Unplasticized
poly(vinyl chloride) (PVC-U)
ISO 11295, Plastics piping systems used for the rehabilitation of pipelines — Classification and overview of
strategic, tactical and operational activities
ISO 11300-3, Piping systems for rehabilitation of underground drains, sewers and water supply networks —
Part 3: Polyethylene (PE) material
EN 1401-1, Plastics piping systems for non-pressure underground drainage and sewerage – Unplasticized
poly(vinyl chloride) (PVC-U) – Part 1: Specifications for pipes, fittings and the system
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11295, ISO 11300-3 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 Assessment of conformity
3.1.1
certification body
impartial body, governmental or non-governmental, possessing the necessary competence and responsibility
to carry out certification of conformity according to given rules of procedure and management

Note 1 to entry: A certification body should preferably operate in accordance with ISO/IEC 17021-1 or ISO/IEC 17065.
[SOURCE: ISO/TS 23818-1:2025, 3.1.1]
3.1.2
inspection body
body that performs inspection
Note 1 to entry: A body can be an organization, or part of an organization.
Note 2 to entry: An inspection body should preferably operate in accordance with ISO/IEC 17020 or ISO/IEC 17021-1.
[SOURCE: ISO/IEC 17020:2012, 3.5, modified — Note 2 to entry added.]
3.1.3
testing laboratory
laboratory which measures, tests, calibrates or otherwise determines the characteristics of the performance
of materials (3.1.13) and products
Note 1 to entry: In the context of this document, the materials and products can be subjected to type testing (3.1.6),
batch release test (3.1.7), process verification test (3.1.8), audit test (3.1.10), and witness test (3.1.12), as applicable.
Note 2 to entry: A testing laboratory should preferably operate in accordance with ISO/IEC 17025.
[SOURCE: ISO/TS 23818-1:2025, 3.1.3]
3.1.4
quality management system
management system to direct and control an organization with regard to quality
Note 1 to entry: Requirements for quality management systems are given in ISO 9001.
[SOURCE: ISO 9000:2015, 3.5.4, modified — Note 1 to entry added.]
3.1.5
quality plan
document setting out the specific quality practices, resources and sequence of activities relevant to a
particular product or range of products
[SOURCE: ISO/TS 23818-1:2025, 3.1.5]
3.1.6
type testing
TT
testing performed to prove that the material (3.1.13), pipe, joint (3.1.21) or assembly (3.1.22) is capable of
conforming to the requirements given in the relevant standard
Note 1 to entry: The type test results should remain valid until there is a change in the material or product or assembly
provided that the process verification tests (3.1.8) are performed regularly.
[SOURCE: ISO/TS 23818-1:2025, 3.1.6]
3.1.7
batch release test
BRT
test performed by or on behalf of the manufacturer on a batch of PVC-U products, which has to be
satisfactorily completed before the batch can be released
Note 1 to entry: A batch can either be a material batch (3.1.14) or a product batch (3.1.16).
[SOURCE: ISO/TS 23818-1:2025, 3.1.7, modified — "PE" changed to "PVC-U".]

3.1.8
process verification test
PVT
test performed by or on behalf of the manufacturer on PVC-U products at specific intervals to confirm that
the process continues to be capable of producing products which conform to the requirements given in the
relevant standard
Note 1 to entry: Such tests are not required to release batches of products and are carried out as a measure of process
control.
[SOURCE: ISO/TS 23818-1:2025, 3.1.8, modified — "PE" changed to "PVC-U"]
3.1.9
process verification test at the “I” stage
PVT-I
test performed by or on behalf of the manufacturer or installer at specific intervals during the installation
process to confirm that the process as specified in the installation manual continues to be capable of
producing installed products which conform to the requirements given in the relevant standard
Note 1 to entry: Such tests are not required to release batches of products and are carried out as a measure of process
control.
[SOURCE: ISO/TS 23818-1:2025, 3.1.9]
3.1.10
audit test
AT
test performed by a test laboratory on behalf of an inspection body (3.1.2) or certification body (3.1.1) to
confirm that the product, continues to conform to the requirements given in the relevant standard
[SOURCE: ISO/TS 23818-1:2025, 3.1.10]
3.1.11
indirect test
IT
test performed by or on behalf of the manufacturer, different from that specified test for that particular
characteristic, having previously verified its correlation with the specified test
[SOURCE: ISO/TS 23818-1:2025, 3.1.11]
3.1.12
witness test
WT
test accepted by an inspection body (3.1.2) or a certification body (3.1.1) for type testing (3.1.6) and/or audit
test (3.1.10), which is carried out by or on behalf of the manufacturer and supervised by a representative of
the inspection or certification body, competent in testing
[SOURCE: ISO/TS 23818-1:2025, 3.1.12]
3.1.13
material
generic term for compositions grouped by families, expressed by generic names, e.g. polypropylene, stainless
steel, brass or EPDM
Note 1 to entry: Definition from European Commission, Directorate-General for Enterprise and Industry, Sub-group
on Product Testing Procedures (EC, DG ENT and IND, SG PTP).
[SOURCE: ISO/TS 23818-1:2025, 3.1.13]

3.1.14
material batch
clearly identified quantity of a given homogeneous compound manufactured under uniform conditions and
defined and identified by the compound manufacturer
[SOURCE: ISO/TS 23818-1:2025, 3.1.14]
3.1.15
product
pipe, fitting, or valve of a clearly identified type intended to be a part of a piping system which the
manufacturer puts on the market
[SOURCE: ISO/TS 23818-1:2025, 3.1.15]
3.1.16
product batch
clearly identified collection of products, manufactured consecutively or continuously under the same
conditions, using the same compound conforming to the same specification
Note 1 to entry: The production batch is defined and identified by the product manufacturer.
[SOURCE: ISO/TS 23818-1:2025, 3.1.16]
3.1.17
lot
clearly identifiable sub-division of a batch for inspection purposes
[SOURCE: ISO/TS 23818-1:2025, 3.1.17]
3.1.18
sample
one or more products drawn from the same production batch or lot (3.1.17), selected at random without
regard to their quality
Note 1 to entry: The number of products in the sample is the sample size.
[SOURCE: ISO/TS 23818-1:2025, 3.1.18]
3.1.19
group
collection of similar products from which samples (3.1.18) are selected for testing purposes
[SOURCE: ISO/TS 23818-1:2025, 3.1.19]
3.1.20
component
product manufactured out of a specific composition compound brought to the market as part of another
product or as a spare part.
Note 1 to entry: For drinking water application, components may be considered as products and be individually
approved (e.g. O-ring, gasket) or they are tested as integral part of a finished product (e.g. in a valve).
[SOURCE: ISO/TS 23818-1:2025, 3.1.20]
3.1.21
joint
connection between two products
[SOURCE: ISO/TS 23818-1:2025, 3.1.21]
3.1.22
assembly
product that can be dismantled into a set of components (3.1.20)

EXAMPLE A test piece consisting of various products.
[SOURCE: ISO/TS 23818-1:2025, 3.1.22]
3.1.23
cavity
space within a mould to be filled to form the moulded product
[SOURCE: ISO/TS 23818-1:2025, 3.1.25, modified — Example deleted]
3.2 Rehabilitation, general
3.2.1
characteristic
property, dimension or other feature of a material (3.1.13) or component (3.1.20)
[SOURCE: ISO/TS 23818-1:2025, 3.2.1]
3.2.2
“M” stage
stage as manufactured, i.e. before any subsequent site processing of components (3.1.20) associated with the
particular renovation technique
[SOURCE: ISO/TS 23818-1:2025, 3.2.2]
3.2.3
“I” stage
stage as installed, i.e. in final configuration after any site processing of components (3.1.20) associated with
the particular renovation technique
[SOURCE: ISO/TS 23818-1:2025, 3.2.3]
3.2.4
nominal size
DN
numerical designation of the size of a component (3.1.20), which is a convenient round number approximately
equal to the inside or outside diameter in millimetres
[SOURCE: ISO/TS 23818-1:2025, 3.2.4]
3.2.5
nominal size
DN/OD
numerical designation of the size of a component related to the outside diameter
[SOURCE: ISO/TS 23818-1:2025, 3.2.5]
3.2.6
nominal outside diameter
d
n
specified outside diameter, in millimetres, assigned to a nominal size DN/OD
[SOURCE: ISO/TS 23818-1:2025, 3.2.6]
4 Abbreviated terms
To avoid misunderstanding, the assessment of conformity abbreviated terms in this clause are defined
as being the same in each language. For the same reason, the terms are given in three languages, English,
French and German.
----
...