ISO 18468:2017

INTERNATIONAL ISO
STANDARD 18468
First edition
2017-06
Ductile iron fittings, accessories and
their joints and valves — Epoxy coating
Raccords, accessoires et leurs assemblages et appareils de robinetterie
en fonte ductile — Revêtement époxy
Reference number
ISO 18468:2017(E)
©
ISO 2017

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ISO 18468:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 18468:2017(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Routine test requirements . 2
4.1 General . 2
4.2 Surface preparation . 3
4.3 Coating appearance. 3
4.4 Coating thickness . 3
4.5 Adhesion (pull off test/cross cut knife test) . 3
4.6 Cross linkage (MIBK/ΔTg) . 3
4.7 Non-porosity . 3
4.8 Repairs . 4
5 Performance requirements . 4
5.1 General . 4
5.2 Materials in contact with water intended for human consumption . 4
5.3 Materials in contact with sewage waters . 4
5.4 Impact resistance . 4
5.5 Resistance to hot water . 4
6 Test methods . 5
6.1 Routine tests . 5
6.1.1 Surface preparation . 5
6.1.2 Coating appearance . 5
6.1.3 Coating thickness . 5
6.1.4 Adhesion (pull off/cross cut knife test) . 5
6.1.5 Cross linkage (MIBK/ΔTg) . 5
6.1.6 Non-porosity . 5
6.2 Performance test . 6
6.2.1 Impact resistance strength. 6
6.2.2 Resistance to hot water . 6
Annex A (normative) Quality assurance . 7
Annex B (normative) Cross cut knife test method . 9
Annex C (informative) Coating material .10
Annex D (informative) Handling, transportation and storage .11
Bibliography .12
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ISO 18468:2017(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).
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For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
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URL: w w w . i s o .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.
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INTERNATIONAL STANDARD ISO 18468:2017(E)
Ductile iron fittings, accessories and their joints and
valves — Epoxy coating
1 Scope
This document specifies the requirements and test methods applicable to factory applied epoxy
coatings (fusion bonded or 2-pack liquid epoxy) for ductile iron fittings and accessories supplied to
ISO 2531 and ISO 7186, and ductile iron valves.
It covers internal and external coatings for use in the conveyance of raw water, potable water and waste
waters for operating temperatures up to 60 °C.
This document contains specifications for performance tests and routine tests of the coating.
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, Ductile iron products for sewerage applications
ISO 8501-1, Preparation of steel substrates before application of paints and related products — Visual
assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates
and of steel substrates after overall removal of previous coatings
ISO 8502-3, Preparation of steel substrates before application of paints and related products — Tests for
the assessment of surface cleanliness — Part 3: Assessment of dust on steel surfaces prepared for painting
(pressure-sensitive tape method)
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 terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
adhesion
pull off test
force per unit area, applied perpendicular to the surface, which is necessary to separate the coating
from its substrate
3.2
cross linkage
chemical reaction between epoxy resin and hardener to form the final cured coating
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ISO 18468:2017(E)

3.3
impact resistance
energy which a coating can withstand without damage under defined testing conditions
3.4
non-porosity
absence of electrical puncture in a high voltage test (holiday test) under defined test conditions
3.5
epoxy coating
factory applied coating 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
3.6
chalking
superficial reaction of epoxy coating (3.5) 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.
3.7
performance test
test which is done once and thereafter only when there is a change in the coating material or
coating process
3.8
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.
3.9
designated zone
area of the casting designated by jointing/mating surfaces or process and test characteristics where a
lower coating thickness standard is applied
EXAMPLE 1 An example of jointing/mating surfaces is joint areas.
EXAMPLE 2 Examples of process and test characteristics are bolt holes, marking, ribs, edges.
3.10
localised thickness
measured thickness at any one point of one coated product
4 Routine test requirements
4.1 General
The following technical requirements shall be demonstrated by routine tests applied in production, on
in-process and finished coated products with defined frequency. Routine tests shall be in accordance
with the overview of requirements provided in Table A.2.
Annex D outlines the handling, transportation and storage of coated products.
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ISO 18468:2017(E)

4.2 Surface preparation
Prior to coating application, all surfaces to be coated shall be blasted to be substantially clean and free
from oil, grease and moisture. The surfaces to be coated shall meet the requirements of Class Sa 2.5
of ISO 8501-1 and ≤ Rating 3 dust quantity of ISO 8502-3. Blasted fittings and accessories shall only
be handled and stored, using tested methods to maintain Sa2.5 finish without any visible rusting and
contamination, until coating application.
4.3 Coating appearance
The epoxy coating 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. pinh
...