ISO 21004:2006

INTERNATIONAL ISO
STANDARD 21004
First edition
2006-11-01
Plastics piping systems — Multilayer
pipes and their joints, based on
thermoplastics, for water supply
Systèmes de canalisations en plastique — Tubes multicouches et
leurs assemblages, à base de thermoplastiques, pour l'alimentation
en eau
Reference number
©
ISO 2006
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©  ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 5
3.1 Terms and definitions related to construction . 5
3.2 Terms and definitions related to construction groups. 5
3.3 Terms and definitions related to geometry. 6
3.4 Terms and definitions related to service conditions . 7
3.5 Terms and definitions related to materials . 7
3.6 Terms and definitions related to material characteristics. 7
4 Products classification. 8
4.1 Construction group . 8
4.2 Reference product standard. 8
4.3 PN Range . 8
4.4 Design coefficient. 8
4.5 Stiffness range. 8
4.6 Specific properties. 9
5 Materials . 9
5.1 General characteristics . 9
5.2 Effect on water quality. 9
5.3 Resistance to weathering . 9
6 Long-term hydrostatic strength . 9
6.1 General. 9
6.2 Procedure I (calculation method). 10
6.3 Procedure II (testing of pipe construction method). 10
7 Geometrical characteristics. 11
7.1 General. 11
7.2 Dimensions. 11
8 Mechanical characteristics . 11
8.1 Control points for pressure characteristics.11
8.2 Structural performance . 11
9 Fittings and valves. 12
10 Fitness for purpose of the system. 12
10.1 Specific properties. 12
10.2 Jointing techniques. 13
10.3 Pressure reduction coefficients for operating temperatures. 17
11 Marking . 17
Annex A (normative) List of the reference product standards. 19
Annex B (normative) Application of design coefficient for multilayer pipes. 20
Annex C (normative) Tear test for polyethylene (PE) saddle assemblies. 21
Annex D (normative) Pressure reduction coefficients. 24
Bibliography . 25

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 21004 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 2, Plastics pipes and fittings for water supplies.

iv © ISO 2006 – All rights reserved

Introduction
An overview of standards to be applied for multilayer pipes and their joints, based on thermoplastics, for water
supply, is given hereafter.
Parts Applicable standards
Materials Relevant reference product standards (see 4.2 and Clause 5 of this International
Standard)
Pipes This International Standard
Fittings Relevant reference product standards (see Clause 9 of this International Standard)
Valves Relevant reference product standards (see Clause 9 of this International Standard)
Fitness for purpose This International Standard (see Clause 10)

INTERNATIONAL STANDARD ISO 21004:2006(E)

Plastics piping systems — Multilayer pipes and their joints,
based on thermoplastics, for water supply
1 Scope
This International Standard specifies the general requirements and the performance requirements for
multilayer pipes based on thermoplastics intended to be used for water supply outside buildings, for buried
water mains and services and for water supplies above ground.
It gives guidance for the design of piping systems consisting of multilayer pipes based on thermoplastics or,
for which at least 60 % of the wall thickness is polymeric material, and the inner layer in contact with water is
made of polymeric material.
The polymeric layers used for the stress-bearing layers are selected from polybutylene (PB), polyethylene
(PE), crosslinked polyethylene (PE-X), polypropylene (PP), chlorinated poly(vinyl chloride) (PVC-C) and
unplasticized poly(vinyl chloride) (PVC-U).
NOTE 1 For the purpose of this document, crosslinked polyethylene (PE-X) as well as adhesives are to be considered
as thermoplastic materials, and polyethylene of raised temperature resistance (PE-RT) is to be considered as
polyethylene (PE).
This document is applicable to piping systems used for the conveyance under pressure of cold water (up to
approximately 20 °C) for drinking. It is also applicable to piping systems for the conveyance of water (up to
and including 40 °C) for general purposes.
It applies where special functional requirements are needed.
NOTE 2 As an example, the different pipe layers can provide information on colour, barrier and mechanical properties,
according to the intended application.
2 Normative references
The following referenced documents are indispensable for the application 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 161-1, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal
pressures ⎯ Part 1: Metric series
ISO 161-2, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal
pressures ⎯ Part 2: Inch-based series
ISO 472, Plastics — Vocabulary
ISO 527-1, Plastics — Determination of tensile properties — Part 1: General principles
ISO 527-1:1993/Cor.1:1994, Plastics — Determination of tensile properties — Part 1: General principles
ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and extrusion
plastics
ISO 1043-1, Plastics — Symbols and abbreviated terms — Part 1: Basic polymers and their special
characteristics
ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
the resistance to internal pressure — Part 1: General method
ISO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
the resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions
ISO 3213, Polypropylene (PP) pipes — Effect of time and temperature on expected strength
ISO 3459, Polyethylene (PE) pressure pipes — Joints assembled with mechanical fittings — Internal under-
pressure test method and requirement
ISO 3501, Assembled joints between fittings and polyethylene (PE) pressure pipes — Test of resistance to
pull out
ISO 3503, Assembled joints between fittings and polyethylene (PE) pressure pipes — Test of leakproofness
under internal pressure when subjected to bending
ISO 4422-1, Pipes and fittings made of unplasticized poly(vinyl chloride) (PVC-U) for water supply ⎯
Specifications ⎯ Part 1: General
ISO 4422-2, Pipes and fittings made of unplasticized poly(vinyl chloride) (PVC-U) for water supply —
Specifications — Part 2: Pipes (with or without integral sockets)
ISO 4422-3, Pipes and fittings made of unplasticized poly(vinyl chloride) (PVC-U) for water supply ⎯
Specifications ⎯ Part 3: Fittings and joints
ISO 4422-4, Pipes and fittings made of unplasticized poly(vinyl chloride) (PVC-U) for water supply ⎯
Specifications ⎯
...