ISO 4427-2:2019

INTERNATIONAL ISO
STANDARD 4427-2
Second edition
2019-08
Plastics piping systems for water
supply, and for drainage and sewerage
under pressure — Polyethylene (PE) —
Part 2:
Pipes
Systèmes de canalisations en plastique destinés à l'alimentation
en eau et aux branchements et collecteurs d'assainissement sous
pression — Polyéthylène (PE) —
Partie 2: Tubes
Reference number
©
ISO 2019
© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 3
5 Material . 3
5.1 Compound . 3
5.2 Identification compound . 3
5.3 Reprocessed and recycled material . 3
6 General characteristics . 3
6.1 Appearance . 3
6.2 Colour . 3
6.3 Effect on water quality . 4
7 Geometrical characteristics . 4
7.1 Measurements . 4
7.2 Mean outside diameter and out-of-roundness (ovality) . 4
7.3 Wall thicknesses and their tolerances . 6
7.4 Coiled pipe .10
7.5 Lengths .10
8 Mechanical characteristics .10
8.1 Conditioning .10
8.2 Requirements .10
8.3 Retest in case of failure at 80 °C .12
9 Physical characteristics .12
9.1 Conditioning .12
9.2 Requirements .12
10 Chemical characteristics of pipes in contact with chemicals .13
11 Performance requirements .13
12 Marking .14
12.1 General .14
12.2 Minimum required marking of pipes .14
Annex A (normative) Pipes with co-extruded layers .15
Annex B (normative) Pipes with peelable layer .17
Annex C (informative) Relationship between PN, MRS, S and SDR .19
Bibliography .20
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
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electrotechnical standardization.
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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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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 138, Plastics pipes, fitting and valves for
the transport of fluids, Subcommittee SC 2, Plastics pipes and fittings for water supplies.
This second edition cancels and replaces the first edition (ISO 4427-2:2007), which has been technically
revised. It also incorporates Amendment ISO 4427-2:2007/Amd. 1:2014.
The main changes compared to the previous edition are:
— Update of the normative references;
— Technical consistency with ISO 4437-2 (see Bibliography [1]).
A list of all parts in the ISO 4427 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 © ISO 2019 – All rights reserved

Introduction
The ISO 4427 series of standards are a set of system standards that specify the requirements for a
piping system and its components when made from polyethylene (PE). The piping system is intended
to be used in buried or above ground applications, for the conveyance of water for human consumption,
raw water prior to treatment, drainage and sewerage under pressure, vacuum sewer systems, and
water for other purposes.
In respect of potential adverse effects on the quality of water intended for human consumption caused
by the products covered by the ISO 4427 series, it does not provide information on the restriction on
the use of products.
NOTE Guidance for assessment of conformity can be found in Reference [2] in the Bibliography.
INTERNATIONAL STANDARD ISO 4427-2:2019(E)
Plastics piping systems for water supply, and for drainage
and sewerage under pressure — Polyethylene (PE) —
Part 2:
Pipes
1 Scope
This document specifies the pipes made from polyethylene (PE) for buried or above ground applications,
intended for the conveyance of:
— water for human consumption;
— raw water prior to treatment;
— drainage and sewerage under pressure;
— vacuum sewer systems;
— water for other purposes.
NOTE 1 The intended uses include sea outfalls, laid in water and pipes suspended below bridges.
Pipes complying with this document are not intended for the transport of water intended for human
consumption in contaminated soils unless special consideration has been taken.
NOTE 2 For example, ISO 21004 provides an alternative solution for use in contaminated soils. See
Reference [3] in the Bibliography.
This document specifies three types of pipe:
— PE pipes (outside diameter d ), including any identification stripes;
n
— PE pipes with co-extruded layers on either or both the outside and/or inside of the pipe (total outside
diameter d ) where all layers have the same MRS rating;
n
— PE pipes (outside diameter d ) having a peelable and contiguous thermoplastics additional layer on
n
the outside of the pipe (“coated pipe”).
This document also specifies the test parameters for the test methods referred to in this document.
In conjunction with the other parts of the ISO 4427 series, this document is applicable to PE pipes, their
joints and to joints with components made of PE and other materials, intended to be used under the
following conditions:
1)
a) a maximum allowable operating pressure (PFA) up to and including 25 bar ;
b) an operating temperature of 20 °C as the reference temperature.
NOTE 3 For other operating temperatures, guidance is given in ISO 4427-1:2019, Annex A.
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
This document covers a range of maximum allowable operating pressures and gives requirements
concerning colours.
NOTE 4 It is the responsibility of the purchaser or specifier to make the appropriate selections from these
aspects, taking into account their particular requirements and installation practices or codes.
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 1133-1, Plastics — Determination of the melt mass-flow rate (MFR) a
...