ISO 16132:2024

Ductile iron pipes and fittings - Seal coats for cement mortar linings

This document specifies the requirements for seal coatings for factory application to the surfaces of cement mortar linings, which are factory applied to the interior of ductile iron pipes and fittings. It provides the performance requirements for short-term sealing efficiency, long-term durability and cyclic pressure, as well as the routine testing requirements for visual appearance, coating thickness and adhesion. This document is applicable to products for potable and irrigation water and for other applications as per agreement between manufacturer and customer.

Tuyaux et raccords en fonte ductile — Seal coats pour les revêtements de mortier de ciment

General Information

• Status: Published
• Publication Date: 07-Mar-2024
• ICS: 23.040.10 - Iron and steel pipes
• ICS: 77.140.75 - Steel pipes and tubes for specific use
• Technical Committee: ISO/TC 5/SC 2 - Cast iron pipes, fittings and their joints
• Drafting Committee: ISO/TC 5/SC 2 - Cast iron pipes, fittings and their joints
• Current Stage: 6060 - International Standard published
• Start Date: 08-Mar-2024
• Due Date: 05-Feb-2024
• Completion Date: 08-Mar-2024

Relations

• Revises: ISO 16132:2016 - Ductile iron pipes and fittings - Seal coats for cement mortar linings
• Effective Date: 06-Aug-2022

Overview

ISO 16132:2024 - "Ductile iron pipes and fittings - Seal coats for cement mortar linings" defines requirements for factory-applied seal coats over cement mortar linings inside ductile iron pipes and fittings. The standard sets performance and routine test criteria to ensure short‑term and long‑term sealing efficiency, durability under cyclic pressure, and consistent factory quality for products used with potable water, irrigation water, or other agreed applications.

Key topics and technical requirements

• Scope & applicability
  • Applies to seal coats applied in factory to cement mortar lined ductile iron pipes and fittings; suitable for potable and irrigation water or other uses by agreement.
• Performance tests
  • Short‑term sealing efficiency (Annex A): pH testing of exposure water (test water pH ~8.0; final test pH shall not exceed 9.5) measured over three successive 24 h exposures.
  • Long‑term sealing efficiency (Annex B): extended exposure requirements with the same pH limit of 9.5, unless otherwise agreed.
  • Cyclic pressure test (Annex C): visual inspection for peeling or cracking (no cracks > 0.8 mm) and subsequent sealing-efficiency verification.
• Routine factory tests
  • Visual appearance (no detrimental irregularities)
  • Coating thickness (Annex D; test film method or ISO 2808 methods)
  • Adhesion (Annex E): X‑cut method per ISO 16276‑2 or area disbond limit (<10% if no X‑cut); acceptance Levels 0–2 where X‑cut is used.
• Materials in contact with drinking water
  • Manufacturers must provide a hygienic certificate meeting ISO 2531:2009 (clause 4.1.4) when used for water applications.
• Marking
  • Each pipe or fitting must carry the manufacturer’s identification and the ISO 16132:2024 reference.

Applications and users

ISO 16132:2024 is relevant to:

• Pipe and fitting manufacturers specifying factory-applied seal coats.
• Water utilities and designers selecting ductile iron pipelines for potable or irrigation systems where reduced leaching is required (e.g., soft waters, long residence times).
• Quality and compliance engineers responsible for factory inspection, testing, and certification.
• Coating suppliers developing seal coat formulations and test evidence for performance.

Practical benefits include improved water quality control, predictable long‑term behavior of lined pipelines, and harmonized factory testing to reduce field failures.

Related standards

• ISO 2531:2009 - materials in contact with drinking water (hygienic requirements)
• ISO 16276‑2:2007 - X‑cut adhesion testing
• ISO 2808 - coating thickness measurement methods

Keywords: ISO 16132:2024, ductile iron pipes, seal coats, cement mortar linings, sealing efficiency, coating thickness, adhesion test, potable water, cyclic pressure.

Standards Content (Sample)

International
Standard
ISO 16132
Third edition
Ductile iron pipes and fittings —
2024-03
Seal coats for cement mortar linings
Tuyaux et raccords en fonte ductile — Seal coats pour les
revêtements de mortier de ciment
Reference number
© ISO 2024
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 . 1
4 Materials in contact with water intended for human consumption . 2
5 Performance test requirements . 2
5.1 Short-term sealing efficiency . . .2
5.2 Long-term sealing efficiency .2
5.3 Cyclic pressure .3
6 Routine test requirements . 3
6.1 General .3
6.2 Visual appearance .3
6.3 Coating thickness .3
6.4 Adhesion .3
7 Marking . . 4
Annex A (normative) Short-term sealing efficiency . 5
Annex B (normative) Long-term sealing efficiency . 8
Annex C (normative) Cyclic pressure test .11
Annex D (normative) Coating thickness measurement using test film .13
Annex E (normative) Adhesion test .15
Annex F (normative) Quality assurance . 17
Bibliography .18

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 Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings,
Subcommittee SC 2, Cast iron pipes, fittings and their joints.
This third edition cancels and replaces the second edition (ISO 16132:2016) which has been technically
revised.
The main changes are as follows:
— X-cut method has been incorporated instead of cross-cut for adhesion test as per ISO 16276-2:2007;
— a list of performance tests and routine tests has been incorporated in Annex F;
— short-term sealing efficiency and long-term sealing efficiency methods in Annex A and Annex B have
been modified.
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 intended purpose of a seal coat is to reduce the contact between a cement mortar lining and the contents
of a water main, thereby restricting the leaching of inorganic materials into the water supply.
Seal coats are usually specified where the pipeline is to convey soft waters and/or where residence times
are very long. Supply water quality data for such pipelines need to be discussed between the prospective
client and the seal coated pipe supplier to ensure the suitability of the product for use.
Attention is drawn to the fact that national or international water supply or water quality regulations can
apply for seal coated cement mortar lined surfaces that are in contact with, or likely to come into contact
with, potable water. Approval can be needed for the individual components of the system, or for the combined
system, depending upon the requirements of those national or international water supply or water quality
regulations when used:
— in accordance with the product manufacturer's instructions for use,
— under any other appropriate conditions defined for that product within any published list of substances,
products and processes approved to those water supply or water quality regulations.

v
International Standard ISO 16132:2024(en)
Ductile iron pipes and fittings — Seal coats for cement mortar
linings
1 Scope
This document specifies the requirements for seal coatings for factory application to the surfaces of cement
mortar linings, which are factory applied to the interior of ductile iron pipes and fittings.
It provides the performance requirements for short-term sealing efficiency, long-term durability and cyclic
pressure, as well as the routine testing requirements for visual appearance, coating thickness and adhesion.
This document is applicable to products for potable and irrigation water and for other applications as per
agreement between manufacturer and customer.
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 2409:2020, Paints and varnishes — Cross-cut test
ISO 2439:2008, Flexible cellular polymeric materials — Determination of hardness (indentation technique)
ISO 2531:2009, Ductile iron pipes, fittings, accessories and their joints for water applications
ISO 10523, Water quality — Determination of pH
ISO 16276-2:2007, Corrosion protection of steel structures by protective paint systems — Assessment of, and
acceptance criteria for, the adhesion/cohesion (fracture strength) of a coating — Part 2: Cross-cut testing and
X-cut testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
ductile iron
type of cast iron used for pipes, fittings and accessories in which graphite is present primarily in spheroidal
form
3.2
fitting
casting other than a pipe, which allows pipeline deviation or change of direction or bore
Note 1 to entry: Flanged sockets, flanged spigots and collars are also classified as fittings.

3.3
test film
film of consistent thickness and density, morphologically stable at the temperature of the substrate during
seal coat application, used as a surrogate surface for the measurement of coating thicknesses
3.4
pipe
casting of uniform bore, with straight axis, having either socket, spigot or flanged ends
Note 1 to entry: This does not apply to flanged sockets or flanged spigots and collars, which are classified as fittings.
3.5
product
seal coated, cement mortar lined iron pipe or fitting
3.6
seal coat
coating applied over a cement mortar lining to control the interactions between the lining and the inside
flowing fluid
3.7
performance test
proof of design test, done once and repeated only after a relevant change of material or supplier of the seal
coat or lining, or relevant change in process design
4 Materials in contact with water intended for human consumption
Manufacturers shall submit the hygienic certificate of seal coat meeting the requirement of ISO 2531:2009,
4.1.4 for the material in contact with water intended for human consumption, in case the pipes are to be
used for water application.
5 Performance test requirements
5.1 Short-term sealing efficiency
When tested in accordance with Annex A, the pH of the test water shall not exceed 9,5.
By agreement between the manufacturer of the product and the customer, other performance tests with
other exposure periods, test waters and/or limits of pH value can be undertaken to suit particular national
or customer requirements.
5.2 Long-term sealing efficiency
When tested in accordance with Annex B, the pH of the test water shall not exceed 9,5 for each of the test
samples.
By agreement between the manufacturer of the product and the customer, other performance tests with
other exposure periods, test waters and/or limits of pH value can be undertaken to suit particular national
or customer requirements.
If the seal coat has been documented by the manufacturer to a national standard and successfully used for
a minimum of five years, the performance of the type test in accordance with Annex B is only required for
significant changes in the coating material, type or formulation which may adversely affect the performance
of the seal coat.
5.3 Cyclic pressure
When tested in accordance with Annex C, visual inspection shall display no peeling of the seal coat or
cracking with a width in excess of 0,8 mm. It is permissible to have some precipitation of white alkaline
deposit.
At the conclusion of the visual inspection, the pipe samples shall immediately be tested for sealing efficiency
in accordance with Annex A. When tested in accordance with Annex A, the pH of the test water shall not
exceed 9,5 in either of the pipe samples.
If the seal coat has been tested and successfully used for a minimum of 10 years, the performance of the type
test in accordance with Annex C is only required for significant changes in the coating material, type, or
formulation which can adversely affect the performance of the seal coat.
6 Routine test requirements
6.1 General
Coating and re-work procedures (e.g. drying regimes for solvent-based coatings and mixing and curing
regimes for multi-component materials) shall be defined by the manufacturer of the product in agreement
with the seal coat supplier, if necessary, so as to enable the product to conform to the requirements of this
document.
The tests specified in 6.2 to 6.4 shall be carried out on factory seal coated pipes or fittings as opposed to
separately prepared samples.
Sampling plans for the tests specified in 6.2 to 6.4, specific to the seal coating material used, the size of the
batch and the storage conditions, shall be specified by the manufacturer of the product for each batch of
product.
Where a non-conforming product is identified, the product shall either be re-worked, so that it meets the
requirements of this document, or be rejected.
6.2 Visual appearance
When examined visually, the seal coated pipes shall be free from any coating irregularities likely to be
detrimental to the performance of the seal coat (as required by the performance tests in this document). The
manufacturer shall define those coating irregularities (e.g. hairline cracks or pinholes) which are considered
not to be detrimental to the performance of the seal coat (as required by the performance tests in this
document), taking into account the nature of the seal coat material.
6.3 Coating thickness
When tested in accordance with Annex D or any appropriate method defined in ISO 2808, the wet or dry
coating thickness shall be within the limits specified by the manufacturer of the product in conjunction with
the seal coat supplier, if necessary.
6.4 Adhesion
When tested in accordance with Annex E, one of the following requirements shall be met:
— where an X-cut is made in the seal coat, the adhesive strength of seal coat shall fall within Level 0 and
Level 2 as defined in Annex E;
— where no X-cut is used, the area of disbonded coating shall be less than 10 % of the test area.
Any area damaged during testing shall be repaired in accordance with a procedure defined by the
manufacturer of the product in agreement with the seal coat supplier.

7 Marking
Each seal coated pipe or fitting shall be identified with the pipe manufacturer's name or mark.
In addition, seal coated pipes shall be indelibly and legibly marked on the external surface with the number
of this document. Where pipes are bundled, the required markings can be applied to the bundle rather than
to individual pipes.
Annex A
(normative)
Short-term sealing efficiency
A.1 Principle
The initial or short-term sealing efficiency of a seal coat applied to a cement mortar lined surface that is
exposed to a given test water is determined by measuring the pH of test water after three successive 24 h
periods of exposure within a seal coated pipe sample.
A.2 Materials
A.2.1 Water sealing material, paraffin wax, solventless epoxy, silicone resin, elastomer seal, or other
suitable sealing material that does not affect the pH of the water.
A.2.2 Test water, having a bicarbonate alkalinity of approximately 26 mg/l as CaCO
...