ISO 8179-2:2017

Ductile iron pipes, fittings, accessories and their joints - External zinc-based coating - Part 2: Zinc-rich paint

ISO 8179-2:2017 specifies an external protective coating system which is factory-applied to ductile iron pipeline components as specified in ISO 2531, ISO 7186 and ISO 16631. This coating system comprises a zinc-rich paint followed by a finishing layer that can be bituminous paint or synthetic resin compatible with zinc rich paint coating. NOTE ISO 8179-1 addresses metallic zinc-based coatings.

Tuyaux, raccords et accessoires en fonte ductile et leurs assemblages — Revêtement extérieur à base de zinc — Partie 2: Peinture riche en zinc

General Information

• Status: Published
• Publication Date: 24-Jul-2017
• ICS: 23.040.10 - Iron and steel pipes
• 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: 9093 - International Standard confirmed
• Start Date: 22-Jun-2023
• Completion Date: 13-Dec-2025

Relations

• Consolidated By: ISO 19085-15:2021 - Woodworking machines - Safety - Part 15: Presses
• Effective Date: 06-Jun-2022
• Revises: ISO 8179-2:1995 - Ductile iron pipes - External zinc coating - Part 2: Zinc rich paint with finishing layer
• Effective Date: 12-Apr-2014

Overview

ISO 8179-2:2017 specifies a factory-applied external protective coating system for ductile iron pipes, fittings, accessories and their joints using zinc-rich paint with an overlying finishing layer (bituminous paint or compatible synthetic resin). The standard defines material composition, application methods, inspection and test procedures to ensure long-term corrosion protection of ductile iron pipeline components used in water and sewerage systems.

Key topics and technical requirements

• Coating composition: Zinc-rich paint with at least 85% zinc by mass in the dry film, followed by a finishing layer compatible with the zinc-rich paint.
• Surface condition: Substrate must be dry and free from rust, oil or non-adhering contaminants; application may be on as-cast annealed or blast-cleaned surfaces.
• Application methods: Coating may be applied by spraying or brushing; finishing layer also by spray or brush.
• Zinc-rich paint mass requirements:
  • Standard: mean mass ≥ 235 g/m² with local minimum 210 g/m².
  • Low-corrosive areas (by agreement): mean 150 g/m² with local minimum 130 g/m².
• Finishing layer thickness: mean dry film thickness ≥ 70 μm with local minimum 50 μm.
• Acceptable damage: Handling damage allowed if area < 5 cm² per m² and minor dimension ≤ 5 mm; larger defects must be repaired.
• Inspection & test methods:
  • Factory token method to determine zinc-rich paint mass (token sizes specified).
  • Dry film thickness measured directly (magnetic gauges) or indirectly on tokens.
  • Annex A describes field verification procedures; Annex B gives soil-related guidance for coating selection.
• Repairs: Permitted using zinc-rich paint meeting the same ≥85% zinc dry-film requirement.

Practical applications

ISO 8179-2:2017 is used to specify and verify external coating systems for ductile iron pipelines to protect against general and localized corrosion in buried and exposed installations. It supports:

• Asset owners and utilities specifying corrosion protection for water and wastewater mains.
• Pipe manufacturers establishing factory quality control for external coatings.
• Contractors and specifiers selecting suitable coating masses and finishing layers based on soil corrosivity.
• Inspection teams performing factory and field verification of coating mass and thickness.

Related standards

• ISO 8179-1 (metallic zinc-based coatings)
• ISO 2531 (ductile iron pipes for water)
• ISO 7186 (ductile iron products for sewerage)
• ISO 16631 (ductile iron compatible with plastic systems)

Keywords: ISO 8179-2:2017, zinc-rich paint, ductile iron pipes, external coating, finishing layer, coating mass, corrosion protection, pipeline components.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 8179-2
Second edition
2017-07
Ductile iron pipes, fittings, accessories
and their joints — External zinc-based
coating —
Part 2:
Zinc-rich paint
Tuyaux, raccords et accessoires en fonte ductile et leurs
assemblages — Revêtement extérieur à base de zinc —
Partie 2: Peinture riche en zinc
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Materials . 1
5 Zinc-rich paint coating . 1
5.1 Pipeline component surface condition . 1
5.2 Method of application . 1
5.3 Coating characteristics . 2
5.4 Zinc-rich paint coating mass . 2
5.5 Repairs to the zinc-rich paint coating . 2
6 Finishing layer . 2
7 Test methods . 3
7.1 Determination of zinc-rich paint coating mass . 3
7.2 Determination of the dry film thickness of the finishing layer . . 3
Annex A (informative) Field verification of the zinc-rich paint coating mass on a finished product 4
Annex B (informative) Field of use in relation to the characteristics of soils: Standard coating .6
Bibliography . 7
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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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 on 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 the following
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.
This second edition cancels and replaces the first edition (ISO 8179-2:1995), which has been technically
revised. The following changes have been made:
2 2
— the minimum quantity of Zn has been increased from 130 g/m to 200 g/m ;
— the revision recognizes the technological advancements in the field regarding zinc-based coatings
to increase the lifetime and reliability of ductile iron pipelines, improving protection to different
types of corrosion (including general and localized) and the use of new alloy enrichments.
A list of all parts in the ISO 8179 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 8179-2:2017(E)
Ductile iron pipes, fittings, accessories and their joints —
External zinc-based coating —
Part 2:
Zinc-rich paint
1 Scope
This document specifies an external protective coating system which is factory-applied to ductile iron
pipeline components as specified in ISO 2531, ISO 7186 and ISO 16631. This coating system comprises a
zinc-rich paint followed by a finishing layer that can be bituminous paint or synthetic resin compatible
with zinc rich paint coating.
NOTE ISO 8179-1 addresses metallic zinc-based coatings.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Materials
The coating materials shall be zinc-rich paint with organic or/and inorganic binder and zinc content of
at least a mass fraction of 85 % in the dry film followed by a finishing layer that can be bituminous paint
or synthetic resin compatible with zinc-rich paint coating.
5 Zinc-rich paint coating
5.1 Pipeline component surface condition
The pipeline component surface shall be dry and free from rust or any non-adhering particles or foreign
matter such as oil or grease.
The zinc-rich paint coating shall be applied to the as-cast annealed external surface of the pipeline
component or to a blast-cleaned or ground surface at the manufacturer’s discretion.
5.2 Method of application
The zinc-rich paint coating shall be applied by a spraying or brushing process onto the pipeline
component surface.
The design and construction of the spray equipment are not within the scope of this document.
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