ISO 24131-1:2023

ISO/DISFDIS 24131-1:2022(E)
ISO TC 5/SC 2/WG 24
Date: 2022-06-0812-22
Secretariat: AFNOR

Internal protection by polymeric lining for ductile iron pipes — Requirements and test methods
— Part 1: Polyurethane lining

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ISO/DIS FDIS 24131--1:2022(E)
© ISO 2022
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2022 – All rights reserved

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ISO/DIS FDIS 24131--1:2022(E)
Contents
Foreword . iv
Introduction. v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Technical requirements . 3
5 Performance requirements . 6
6 Test methods . 7
Annex A (normative) Quality assurance . 11
Annex B (informative) Handling, transportation and storage . 13
Bibliography . 14
© ISO 2022 – All rights reserved iii

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ISO/DIS FDIS 24131--1:2022(E)
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 5, Ferrous metal pipes and metallic fittings,
Subcommittee SC 2, Cast iron pipes, fittings and their joints.
A list of all parts in the ISO 24131 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 © ISO 2022 – All rights reserved

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ISO/DIS FDIS 24131--1:2022(E)
Introduction
The ISO 24131 series specifies the requirements and test methods applicable to factory applied polymeric
linings for ductile iron pipes suppliedaccording to ISO 2531, ISO 7186 and ISO 16631. The ISO 24131
series includesis intended to include several types of polymeric linings.
© ISO 2022 – All rights reserved v

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FINAL DRAFT INTERNATIONAL STANDARD ISO/DIS FDIS 24131--1:2022(E)

Internal protection by polymeric lining for ductile iron pipes —
Requirements and test methods — Part 1: Polyurethane lining
1 Scope
This document specifies the requirements and test methods applicable to factory applied internal
polyurethane lining for ductile iron pipes according to ISO 2531, ISO 7186 and ISO 16631.
It covers internal linings for use in the conveyance of raw water, potable water and sewage water for
operating temperature up to 50 °C.
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 2531, Ductile iron pipes, fittings, accessories and their joints for water applications
ISO 7186:2011, Ductile iron products for sewerage applications
ISO 16631, Ductile iron pipes, fittings, accessories and their joints compatible with plastic (PVC or PE) piping
systems, for water applications and for plastic pipeline connections, repair and replacement
ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO
surface profile comparators for the assessment of abrasive blast-cleaned surfaces
ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore
hardness)
ISO 62, Plastics — Determination of water absorption
ISO 4624, Paints and varnishes — Pull-off test for adhesion
ISO 527-3, Plastics — Determination of tensile properties — Part 3: Test conditions for films and sheets
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2531 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/
3.1
polyurethane lining
© ISO 2022 – All rights reserved 1

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ISO/DISFDIS 24131-1:2022(E)
factory applied lining which consists of polyurethane (3.2) on the inside of the pipe
Note 1 to entry: See Figure 1.


Key
1 gasket seat
2 pipe barrel
3 spigot end
4 lining
5 internal socket profile
Figure 1 — Location of the defined pipe areas
3.2
polyurethane
polymers made by combining diisocyanates and polyols
3.3
operating temperature
applicable temperatures under which the product maintains its properties
3.4
chalking
superficial reaction of polyurethane lining (3.1) due to exposure to UV-radiation
Note 1 to entry: The process is confined to the surface only and results in a dulling of the surface.
3.5
minimum lining thickness
minimum value of the lining thickness measured at the lined item
3.6
adhesion
2 © ISO 2022 – All rights reserved

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ISO/DIS FDIS 24131--1:2022(E)
force per unit area, applied perpendicular to the surface, which is necessary to separate the lining from
its substrate
3.7
cross linkage
chemical reaction between polyurethane (3.2) resin and hardener to form the final cured lining
3.8
non-porosity
absence of electrical puncture in a high voltage test (holiday test) under defined test conditions
3.9
hardness
resistance of the lining to the penetration of a ball under defined test conditions
3.10
protection of pipe ends
factory applied coating/lining on spigot end and internal socket profile of pipes
Note 1 to entry: See Figure 1.
3.11
abrasion resistance
ability of materials and structures to withstand abrasion
3.12
indirect impact resistance
impact energy applied from outside of the pipe with deformation to which a lining can withstand without
damage under defined test conditions
3.13
specific lining resistance
surface related electric resistance of the lining perpendicular to the pipe wall
3.14
ovalization
100 times the measured vertical deflection, (caused by the applied load) divided by the measured pipe
external diameter
3.15
routine test
test carried out to control the manufacturing process
Note 1 to entry: The frequency of the test is defined by this document or the manufacturer.
3.16
performance test
test which is done once and thereafter only when there is a change in the lining material or lining process
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ISO/DISFDIS 24131-1:2022(E)
4 Technical requirements
4.1 General
The following technical requirements shall be demonstrated by routine tests applied in production, on
in-process and finished lined products with defined frequency. Routine tests shall be in accordance with
the overview of requirements provided in Table A.2.
The information about qualityQuality assurance for polyurethane lining is givenshall be in accordance
with Annex A.

4.34.2 Surface preparation
Prior to lining application, all surfaces to be lined shall be substantially clean and free from oil, grease and
moisture.
In cold weather, or anytime when moisture tends to condense on the surface of the pipe, it shall be
uniformly warmed for sufficient time to dry prior to cleaning. The surface temperature shall be
maintained at least 3 °C above the dew point.
Surface preparation shall be designed in order to reach the required performances specified in this
document. It is the responsibility of the manufacturer to demonstrate the fitness for purpose of surface
preparation technology and to put in place a quality control procedure to ensure the stability of those
performances.
NOTE The requirements of Class Sa 2.5 of ISO 8501-1 and ≤ Rating 3 dust quantity and Class 2 for dust size of
ISO 8502-3 can be applied.
4.44.3 Surface roughness
The surface roughness Ra in accordance with ISO 8503-1 shall be at least 12,5 μm which is equivalent to
anchored profile Rz of 63 μm or higher if required by the lining material provider or manufacturer.
4.54.4 Lining appearance
The lining of the final product shall be of
— uniform colour, except for permitted marking;
— uniform appearance and smoothness, except for allowable repairs;
— free of visible defects (i.e. pinholes, bubbles, blisters, wrinkles, cracks or voids).
Slight superficial colour variations due to repairs or long exposure to sunlight (chalking) are permissible.
4.64.5 Lining thickness
When measured in accordance with the method defined in 6.1.4, the lining thickness shall be as indicated
in Table 1 for water applications and in Table 2 for sewage applications.
Table 1 — Minimum lining thickness and test tension for water applications
Nominal size Minimum lining thickness Test tension
DN μm kV
80 to 2 600 800 4
4 © ISO 2022 – All rights reserved

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ISO/DIS FDIS 24131--1:2022(E)
Table 2 — Minimum lining thickness and test tension for sewage applications
Nominal size Minimum lining thickness Test tension
DN μm kV
80 to 700 800 4
800 to 2 600 1 000 5
4.74.6 Adhesion
Adhesion shall be tested in accordance with the test method defined in 6.1.5 on production samples.
The lining adhesion shall achieve an average value of at least 8,0 MPa. The manufacturer shall determine
the test locations on the products.
4.84.7 Cross linkage
Determination of cross linkage by hardness measurement of the lining materials serves as a production
control. It is calibrated by a differential scanning calorimetry (DSC) test, see 6.1.6.
The test shall be carried out directly after production on a cured proxy sample under the same production
condition as the pipe at room temperature (23 ± 2) °C. The test method of ISO 868 shall be used.
4.94.8 Non-porosity
When tested in accordance with the test method defined in 6.1.7, the lining shall be free from porosity.
For 800 μm minimum lining thickness, the test tension shall be 4 kV. For 1 000 μm minimum lining
thickness, the test tension shall be 5 kV. The scanning electrode shall be passed over the surface of the
lining being inspected with a continuous, relative movement not exceeding 300 mm/s. This requirement
does not apply to pipe ends.
The electrode shall not be damaged and shall be in constant touch with the lining.
For thicker linings, a higher test voltage may be used by agreement between the manufacturer and the
purchaser.
4.104.9 Hardness
The different applications (e.g. drinking water, sewage) can use different hardness which are indicated
in the pipe manufacturer’s catalogue. They shall be tested in accordance with 6.1.8.
4.114.10 Protection of pipe ends
Spigot end and internal socket profile (see Figure 1) shall be coated in accordance with ISO 2531,
ISO 7186 and ISO 16631.
4.124.11 Marking
All pipes shall be marked legibly and durably according to the pipe standards, ISO 2531, ISO 7186 and
ISO 16631. Reference to this document shall be legibly and durably applied by any method upon the
external surface.
Marking shall be checked in accordance with the test method described in 6.1.9.
4.134.12 Repairs
Repairs shall be carried out when there is a fault. The fault can be
— localized damage,
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ISO/DISFDIS 24131-1:2022(E)
— holding point,
— earthing surface for the non-porosity test, or
— other lining fault.
The lining manufacturer should establish the repair procedure. The material to be used shall satisfy two
conditions:
— be suitable for protecting pipes under the required service conditions;
— be compatible in all aspects with the previously applied lining.
The repairs shall conform to the requirements specified in 4.5, 4.7 and 4.8.
The information about handling, transportation and storage of polyurethane lined pipes is given in
Annex B.
5 Performance requirements
5.1 General
The following technical requirements shall be demonstrated by performance tests in order to verify the
lining material and process prior to production lining. Performance tests shall be in accordance with the
overview of requirements provided in Table A.1. Where there is a change of lining material or process,
the performance tests shall be undertaken on the new lining material or process.
5.2 Materials in contact with water intended for human consumption
When used under the conditions for which it is designed, in permanent or in temporar
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24131-1
ISO/TC 5/SC 2
Internal protection by polymeric
Secretariat: AFNOR
lining for ductile iron pipes —
Voting begins on:
2023-01-05 Requirements and test methods —
Voting terminates on:
Part 1:
2023-03-02
Polyurethane lining
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 24131-1:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2023

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ISO/FDIS 24131-1:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 24131-1
ISO/TC 5/SC 2
Internal protection by polymeric
Secretariat: AFNOR
lining for ductile iron pipes —
Voting begins on:
Requirements and test methods —
Voting terminates on:
Part 1:
Polyurethane lining
COPYRIGHT PROTECTED DOCUMENT
© 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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: +41 22 749 01 11
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: copyright@iso.org
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 24131-1:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022

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ISO/FDIS 24131-1:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Technical requirements . 3
4.1 General . 3
4.2 Surface preparation . 3
4.3 Surface roughness . 4
4.4 Lining appearance . 4
4.5 Lining thickness . 4
4.6 Adhesion . 4
4.7 Cross linkage . 4
4.8 Non-porosity . 5
4.9 Hardness . 5
4.10 Protection of pipe ends . 5
4.11 Marking . 5
4.12 Repairs . 5
5 Performance requirements . .6
5.1 General . 6
5.2 Materials in contact with water intended for human consumption . 6
5.3 Abrasion resistance only for sewage applications . 6
5.4 Chemical resistance only for sewage applications . 6
5.5 Indirect impact resistance . 6
5.6 Resistance to hot water . 6
5.7 Specific lining resistance . . 6
5.8 Resistance to ovalization . 7
5.9 Elongation at break . 7
6 Test methods . 7
6.1 Routine tests . . 7
6.1.1 Surface preparation . 7
6.1.2 Surface roughness . 7
6.1.3 Lining appearance . . 7
6.1.4 Lining thickness . 7
6.1.5 Adhesion . 7
6.1.6 Differential scanning calorimetry (DSC) . 8
6.1.7 Non-porosity . 8
6.1.8 Hardness . 8
6.1.9 Marking . . . 8
6.1.10 Repairs . 8
6.2 Performance test . 8
6.2.1 Abrasion resistance only for sewage applications . 8
6.2.2 Chemical resistance only for sewage applications . 8
6.2.3 Indirect impact resistance . 8
6.2.4 Resistance to hot water . 9
6.2.5 Specific lining resistance . 9
6.2.6 Resistance to ovalization . 10
6.2.7 Elongation at break . 10
Annex A (normative) Quality assurance .11
Annex B (informative) Handling, transportation and storage .13
Bibliography .14
iii
© ISO 2022 – All rights reserved

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ISO/FDIS 24131-1:2022(E)
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 5, Ferrous metal pipes and metallic fittings,
Subcommittee SC 2, Cast iron pipes, fittings and their joints.
A list of all parts in the ISO 24131 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
  © ISO 2022 – All rights reserved

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ISO/FDIS 24131-1:2022(E)
Introduction
The ISO 24131 series specifies the requirements and test methods applicable to factory applied
polymeric linings for ductile iron pipes according to ISO 2531, ISO 7186 and ISO 16631. The ISO 24131
series is intended to include several types of polymeric linings.
v
© ISO 2022 – All rights reserved

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 24131-1:2022(E)
Internal protection by polymeric lining for ductile iron
pipes — Requirements and test methods —
Part 1:
Polyurethane lining
1 Scope
This document specifies the requirements and test methods applicable to factory applied internal
polyurethane lining for ductile iron pipes according to ISO 2531, ISO 7186 and ISO 16631.
It covers internal linings for use in the conveyance of raw water, potable water and sewage water for
operating temperature up to 50 °C.
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 2531, Ductile iron pipes, fittings, accessories and their joints for water applications
ISO 7186:2011, Ductile iron products for sewerage applications
ISO 16631, Ductile iron pipes, fittings, accessories and their joints compatible with plastic (PVC or PE)
piping systems, for water applications and for plastic pipeline connections, repair and replacement
ISO 8503-1, Preparation of steel substrates before application of paints and related products — Surface
roughness characteristics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO
surface profile comparators for the assessment of abrasive blast-cleaned surfaces
ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore
hardness)
ISO 62, Plastics — Determination of water absorption
ISO 4624, Paints and varnishes — Pull-off test for adhesion
ISO 527-3, Plastics — Determination of tensile properties — Part 3: Test conditions for films and sheets
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2531 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/
1
© ISO 2022 – All rights reserved

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ISO/FDIS 24131-1:2022(E)
3.1
polyurethane lining
factory applied lining which consists of polyurethane (3.2) on the inside of the pipe
Note 1 to entry: See Figure 1.
Key
1 gasket seat
2 pipe barrel
3 spigot end
4 lining
5 internal socket profile
Figure 1 — Location of the defined pipe areas
3.2
polyurethane
polymers made by combining diisocyanates and polyols
3.3
operating temperature
applicable temperatures under which the product maintains its properties
3.4
chalking
superficial reaction of polyurethane lining (3.1) due to exposure to UV-radiation
Note 1 to entry: The process is confined to the surface only and results in a dulling of the surface.
3.5
minimum lining thickness
minimum value of the lining thickness measured at the lined item
3.6
adhesion
force per unit area, applied perpendicular to the surface, which is necessary to separate the lining from
its substrate
3.7
cross linkage
chemical reaction between polyurethane (3.2) resin and hardener to form the final cured lining
3.8
non-porosity
absence of electrical puncture in a high voltage test (holiday test) under defined test conditions
3.9
hardness
resistance of the lining to the penetration of a ball under defined test conditions
2
  © ISO 2022 – All rights reserved

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ISO/FDIS 24131-1:2022(E)
3.10
protection of pipe ends
factory applied coating/lining on spigot end and internal socket profile of pipes
Note 1 to entry: See Figure 1.
3.11
abrasion resistance
ability of materials and structures to withstand abrasion
3.12
indirect impact resistance
impact energy applied from outside of the pipe with deformation to which a lining can withstand
without damage under defined test conditions
3.13
specific lining resistance
surface related electric resistance of the lining perpendicular to the pipe wall
3.14
ovalization
100 times the measured vertical deflection, (caused by the applied load) divided by the measured pipe
external diameter
3.15
routine test
test carried out to control the manufacturing process
Note 1 to entry: The frequency of the test is defined by this document or the manufacturer.
3.16
performance test
test which is done once and thereafter only when there is a change in the lining material or lining
process
4 Technical requirements
4.1 General
The following technical requirements shall be demonstrated by routine tests applied in production,
on in-process and finished lined products with defined frequency. Routine tests shall be in accordance
with the overview of requirements provided in Table A.2.
Quality assurance for polyurethane lining shall be in accordance with Annex A.
4.2 Surface preparation
Prior to lining application, all surfaces to be lined shall be substantially clean and free from oil, grease
and moisture.
In cold weather, or anytime when moisture tends to condense on the surface of the pipe, it shall be
uniformly warmed for sufficient time to dry prior to cleaning. The surface temperature shall be
maintained at least 3 °C above the dew point.
Surface preparation shall be designed in order to reach the required performances specified in this
document. It is the responsibility of the manufacturer to demonstrate the fitness for purpose of surface
3
© ISO 2022 – All rights reserved

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ISO/FDIS 24131-1:2022(E)
preparation technology and to put in place a quality control procedure to ensure the stability of those
performances.
NOTE The requirements of Class Sa 2.5 of ISO 8501-1 and ≤ Rating 3 dust quantity and Class 2 fo
...