ISO 24131-2:2023

INTERNATIONAL ISO
STANDARD 24131-2
First edition
2023-03
Internal protection by polymeric
lining for ductile iron pipes —
Requirements and test methods —
Part 2:
Epoxy lining
Protection interne des tuyaux en fonte ductile par revêtement
polymérique — Exigences et méthodes d'essai —
Partie 2: Revêtement époxy
Reference number
© ISO 2023
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ii
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 Lining appearance . 4
4.4 Minimum lining thickness . 4
4.5 Adhesion (pull off test/cross cut knife test) . 4
4.6 Cross linkage (MIBK/ΔTg) . 4
4.7 Non-porosity . 4
4.8 Protection of pipe ends . 4
4.9 Marking . 5
4.10 Repairs . 5
5 Performance requirements . .5
5.1 General . 5
5.2 Materials in contact with water intended for human consumption . 5
5.3 Abrasion resistance only for sewage applications . 5
5.4 Chemical resistance only for sewage applications . 6
5.5 Impact resistance . 6
5.6 Indirect impact resistance . 6
5.7 Resistance to hot water . 6
5.8 Resistance to ovalization . 6
6 Test methods . 6
6.1 Routine tests . . 6
6.1.1 Surface preparation . 6
6.1.2 Lining appearance . . 6
6.1.3 Lining thickness . 7
6.1.4 Adhesion . 7
6.1.5 Cross linkage (MIBK/ΔTg). 7
6.1.6 Non-porosity . 7
6.1.7 Marking . . . 7
6.1.8 Repairs . 7
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 Impact resistance . 8
6.2.4 Indirect impact resistance . 8
6.2.5 Resistance to hot water . 8
6.2.6 Resistance to ovalization . 8
Annex A (normative) Quality assurance .10
Annex B (normative) Cross cut knife test method .12
Annex C (informative) Handling, transportation and storage .13
Bibliography .14
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
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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).
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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
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
INTERNATIONAL STANDARD ISO 24131-2:2023(E)
Internal protection by polymeric lining for ductile iron
pipes — Requirements and test methods —
Part 2:
Epoxy lining
1 Scope
This document specifies the requirements and test methods applicable to factory applied internal
epoxy 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 4624, Paints and varnishes — Pull-off test for adhesion
ISO 7186:2011, Ductile iron products for sewerage applications
ISO 11357-2, Plastics — Differential scanning calorimetry (DSC) — Part 2: Determination of glass transition
temperature and step height
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
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
epoxy lining
factory applied lining
Note 1 to entry: It can be with either
— fusion bonded epoxy powder applied by spraying or dipping in a fluidised bed on preheated parts, with or
without post curing, or
— two-pack liquid epoxy consisting of a base and a catalyst component which are mixed together in the
proportion specified by the manufacturer before application.
Note 2 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
epoxy
family of basic components or cured end products of epoxy resins, which are a class of reactive
prepolymers and polymers which contain epoxide groups
Note 1 to entry: Epoxy is created by mixing two different compounds known as a resin and a hardener.
3.3
operating temperature
applicable temperatures under which the product maintains its properties
3.4
chalking
superficial reaction of epoxy 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
local thickness
measured thickness at any one point of one lined product
3.7
adhesion
pull off test
force per unit area, applied perpendicular to the surface, which is necessary to separate the lining from
its substrate
3.8
cross linkage
chemical reaction between epoxy resin and hardener to form the final cured lining
3.9
non-porosity
absence of electrical puncture in a high voltage test (holiday test) 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
impact resistance
energy which a lining can withstand without damage under defined test conditions
3.13
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
3.14
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 epoxy 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
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.
4.3 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.
4.4 Minimum lining thickness
When measured in accordance with the method defined in 6.1.3, the minimum local thickness shall be
greater than 200 μm and the minimum average thickness shall be greater than or equal to 250 μm.
4.5 Adhesion (pull off test/cross cut knife test)
Adhesion (pull off test) shall be tested in accordance with the test method defined
...