ISO 4427-1:2019

Plastics piping systems for water supply and for drainage and sewerage under pressure - Polyethylene (PE) - Part 1: General

This document specifies the general aspects of polyethylene (PE) compounds for the manufacture of pressure pipes and fittings (mains and service pipes) 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. This document also specifies the test parameters and requirements for the test methods referred to in this document. In conjunction with other parts of the ISO 4427 series, this document is applicable to PE pipes and fittings, their joints and to joints with components made of PE and other materials, intended to be used under the following conditions: a) a maximum allowable operating pressure (PFA) up to and including 25 bar[1]; b) an operating temperature of 20 °C as the reference temperature. NOTE 1 For other operating temperatures, guidance is given in Annex A. The ISO 4427 series covers a range of maximum allowable operating pressures and gives requirements concerning colours. NOTE 2 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. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.

Systèmes de canalisations en plastique destinés à l'alimentation en eau et aux branchements et collecteurs d'assainissement sous pression — Polyéthylène (PE) — Partie 1: Généralités

General Information

• Status: Published
• Publication Date: 05-Aug-2019
• ICS: 23.040.20 - Plastics pipes
• ICS: 23.040.45 - Plastics fittings
• ICS: 91.140.60 - Water supply systems
• ICS: 93.025 - External water conveyance systems
• Technical Committee: ISO/TC 138/SC 2 - Plastics pipes and fittings for water supplies
• Drafting Committee: ISO/TC 138/SC 2/WG 4 - PE piping systems for water supply
• Current Stage: 9092 - International Standard to be revised
• Start Date: 15-Dec-2025
• Completion Date: 27-Dec-2025

Relations

• Revises: ISO 4427-1:2007 - Plastics piping systems - Polyethylene (PE) pipes and fittings for water supply - Part 1: General
• Effective Date: 20-Aug-2016
• Revises: ISO 4427-1:2007/Amd 1:2015 - Plastics piping systems - Polyethylene (PE) pipes and fittings for water supply - Part 1: General - Amendment 1: Melt mass-flow rate (MFR) for PE 80 and PE 100
• Effective Date: 20-Aug-2016

Overview

ISO 4427-1:2019 - Plastics piping systems for water supply and for drainage and sewerage under pressure - Polyethylene (PE) - Part 1: General - sets out the general requirements for polyethylene (PE) compounds used to manufacture pressure pipes and fittings for buried or above‑ground applications. It applies to systems intended for the conveyance of potable water, raw water prior to treatment, drainage and sewerage under pressure (including vacuum sewer systems), and other water uses. The standard defines material aspects, test parameters and requirements for referenced test methods and is used together with the other parts of the ISO 4427 series.

Key topics and requirements

• Material scope: Specifies general aspects of PE compounds (virgin/reprocessed granules, additives, pigments and colour requirements).
• Service conditions: Applicable for systems with a maximum allowable operating pressure (PFA) up to and including 25 bar and a reference operating temperature of 20 °C (guidance for other temperatures is provided in Annex A).
• Test methods and parameters: Defines parameters and requirements for test methods referenced in the standard (for example, melt flow, density, long‑term hydrostatic strength and resistance to internal pressure are included via normative references).
• Dimensions and terminology: Standardizes geometrical terms (DN/OD, nominal wall thickness, SDR/series), symbols and tolerances used across PE piping systems.
• Jointing and compatibility: Applies in conjunction with other parts of ISO 4427 to pipes, fittings and joints - including joints between PE and other materials - and addresses fusion compatibility and joint test procedures.
• Water quality considerations: Includes requirements and guidance on potential effects of PE components on water intended for human consumption.
• Purchaser responsibility: The purchaser/specifier must select appropriate material grades, pressures, colours and installation practices to meet local codes and project requirements.

Practical applications

ISO 4427-1:2019 is essential for:

• Design and specification of PE water mains, service pipes and pressure sewer lines
• Manufacturers of PE pipes, fittings and compound suppliers
• Utilities, municipal water authorities and wastewater system planners
• Civil and pipeline engineers, consultants and procurement teams
• Test labs and conformity assessment bodies verifying PE compound and piping performance

Related standards

• ISO 4427-2 (Pipes) and ISO 4427-3 (Fittings) - complementary parts of the ISO 4427 series
• Relevant normative references cited in the document (examples include ISO 1133, ISO 1167, ISO 9080, ISO 12162, ISO 13477/78/79) for specific test methods and material classification

ISO 4427-1:2019 is a foundational reference for anyone specifying or manufacturing polyethylene piping systems for water supply and pressure drainage, providing consistent terminology, material guidance and test requirements for reliable, compliant systems.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4427-1
Second edition
2019-08
Plastics piping systems for water
supply and for drainage and sewerage
under pressure — Polyethylene (PE) —
Part 1:
General
Systèmes de canalisations en plastique destinés à l'alimentation
en eau et aux branchements et collecteurs d'assainissement sous
pression — Polyéthylène (PE) —
Partie 1: Généralités
Reference number
©
ISO 2019
© ISO 2019
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]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
3.1 Geometrical terms . 3
3.2 Material terms . 5
3.3 Terms related to material characteristics . 5
3.4 Terms related to service conditions . 6
3.5 Terms related to joints . 6
4 Symbols and abbreviated terms . 7
4.1 Symbols . 7
4.2 Abbreviated terms . 7
5 Material . 8
5.1 Material of the component . 8
5.2 Compound . 8
5.2.1 Additives and pigments . 8
5.2.2 Colour . 8
5.3 Physical characteristics of the compound . 9
5.3.1 Characteristics of the compound in the form of granules . 9
5.3.2 Characteristics of the compound in the form of pipe .10
5.4 Fusion compatibility .12
5.5 Classification and designation .13
6 Effects on water quality .13
Annex A (informative) Pressure reduction coefficient .14
Annex B (informative) Resistance to rapid crack propagation .15
Bibliography .17
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).
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 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 4427-1:2007), which has been technically
revised. It also incorporates Technical Corrigendum ISO 4427-1:2007/Cor 1:2008 and Amendment
ISO 4427-1:2007/Amd 1:2015.
The main changes compared to the previous edition are:
— update of the normative references;
— technical consistency with ISO 4437-1 (see Reference [1] in the Bibliography).
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 4427-1:2019(E)
Plastics piping systems for water supply and for drainage
and sewerage under pressure — Polyethylene (PE) —
Part 1:
General
1 Scope
This document specifies the general aspects of polyethylene (PE) compounds for the manufacture of
pressure pipes and fittings (mains and service pipes) 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.
This document also specifies the test parameters and requirements for the test methods referred to in
this document.
In conjunction with other parts of the ISO 4427 series, this document is applicable to PE pipes and
fittings, 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 1 For other operating temperatures, guidance is given in Annex A.
The ISO 4427 series covers a range of maximum allowable operating pressures and gives requirements
concerning colours.
NOTE 2 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 3, Preferred numbers — Series of preferred numbers
ISO 472, Plastics — Vocabulary
ISO 1043-1, Plastics — Symbols and abbreviated terms — Part 1: Basic polymers and their special
characteristics
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
ISO 1133-1, Plastics — Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR)
of thermoplastics — Part 1: Standard method
ISO 1167-1:2006, 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 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: Immersion
method, liquid pycnometer method and titration method
ISO 1183-2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density
gradient column method
ISO 4427-2, Plastics piping systems for water supply, and for drainage and sewerage under pressure —
Polyethylene (PE) — Part2: Pipes
ISO 4427-3, Plastics piping systems for water supply, and for drainage and sewerage under pressure —
Polyethylene (PE) — Part 3: Fittings
ISO 6259-1, Thermoplastics pipes — Determination of tensile properties — Part 1: General test method
ISO 6259-3, Thermoplastics pipes — Determination of tensile properties — Part 3: Polyolefin pipes
ISO 6964, Polyolefin pipes and fittings — Determination of carbon black content by calcination and
pyrolysis — Test method
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
ISO 11357-6, Plastics — Differential scanning calorimetry (DSC) — Part 6: Determination of oxidation
induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)
ISO 11413, Plastics pipes and fittings — Preparation of test piece assemblies between a polyethylene (PE)
pipe and an electrofusion fitting
ISO 11414, Plastics pipes and fittings — Preparation of polyethylene (PE) pipe/pipe or pipe/fitting test
piece assemblies by butt fusion
ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification,
designation and design coefficient
ISO 13477, Thermoplastics pipes for the conveyance of fluids — Determination of resistance to rapid crack
propagation (RCP) — Small-scale steady-state test (S4 test)
ISO 13478, Thermoplastics pipes for the conveyance of fluids — Determination of resistance to rapid crack
propagation (RCP) — Full-scale test (FST)
ISO 13479, Polyolefin pipes for the conveyance of fluids — Determination of resistance to crack
propagation — Test method for slow crack growth on notched pipes
ISO 13953, Polyethylene (PE) pipes and fittings — Determination of the tensile strength and failure mode of
test pieces from a butt-fused joint
ISO 13954, Plastics pipes and fittings — Peel decohesion test for polyethylene (PE) electrofusion assemblies
of nominal outside diameter greater than or equal to 90 mm
ISO 15512, Plastics — Determination of water content
ISO 16871, Plastics piping and ducting systems — Plastics pipes and fittings — Method for exposure to
direct (natural) weathering
2 © ISO 2019 – All rights reserved

EN 12099, Plastics piping systems — Polyethylene piping materials and components — Determination of
volatile content
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3, ISO 472 and ISO 1043-1 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 Geometrical terms
3.1.1
nominal size
DN/OD
numerical designation of the size of a component related to the outside diameter
Note 1 to entry: It is a convenient round number approximately equal to the manufacturing dimension in
millimetres (mm). It is not applicable to components designated by thread size.
3.1.2
nominal outside diameter
d
n
specified outside diameter assigned to a nominal size DN/OD
Note 1 to entry: Nominal outside diameter is expressed in millimetres.
3.1.3
outside diameter at any point
d
e
value of the measurement of the outside diameter through its cross-section at any point of the pipe,
rounded to the next greater 0,1 mm
3.1.4
mean outside diameter
d
em
value of the measurement of the outer circumference of the pipe or spigot end of a fitting in any cross-
section divided by π (= 3,142), rounded to the next greater 0,1 mm
3.1.5
minimum mean outside diameter
d
em,min
minimum value for the mean outside diameter as specified for a given nominal size
3.1.6
maximum mean outside diameter
d
em,max
maximum value for the mean outside diameter as specified for a given nominal size
3.1.7
out-of-roundness
ovality
difference between the maximum and the minimum outside diameters in the same cross-section of a
pipe or spigot
3.1.8
nominal wall thickness
e
n
numerical designation of the wall thickness of a component, which is a convenient round number,
approximately equal to the manufacturing dimension in millimetres (mm)
Note 1 to entry: For thermoplastics components conforming to the different parts of the ISO 4427 series, the
value of the nominal wall thickness, e , is identical to the specified minimum wall thickness at any point, e .
n min
3.1.9
wall thickness at any point
e
wall thickness at any point around the circumference of a component rounded to the next greater 0,1 mm
Note 1 to entry: The symbol for the wall thickness of the fittings body at any point is E.
3.1.10
minimum wall thickness at any point
e
min
minimum value for the wall thickness at any point around the circumference of a component, as
specified
3.1.11
maximum wall thickness at any point
e
max
maximum value for the wall thickness at any point around the circumference of a component, as
specified
3.1.12
mean wall thickness
e
m
arithmetical mean of a number of measurements of the wall thickness, regularly spaced around the
circumference and in the same cross-section of a component, including the measured minimum and the
measured maximum values of the wall thickness in that cross-section
3.1.13
pipe series
S
dimensionless number for pipe designation conforming to ISO 4065
Note 1 to entry: The relationship between the pipe series, S, and the standard dimension ratio, SDR, is given by
the following formula from ISO 4065 (see Bibliography [3]):
SDR1−
S =
3.1.14
standard dimension ratio
SDR
numerical designation of a pipe series, which is a convenient round number, approximately equal to the
dimension ratio of the nominal outside diameter, d , and the nominal wall thickness, e
n n
3.1.15
tolerance
permitted variation of the specified value of a quantity, expressed as the difference between the
permitted maximum and the permitted minimum value
4 © ISO 2019 – All rights reserved

3.1.16
wall thickness tolerance
t
y
permitted difference between the wall thickness at any point, e, and the nominal wall thickness, e
n
Note 1 to entry: e ≤ e ≤ e + t .
n n y
3.2 Material terms
3.2.1
virgin material
compound in the form of granules that has not been subjected to use or processing other than that
required for its manufacture and to which no reprocessed or recycled materials have been added
3.2.2
own reprocessed material
material prepared from clean, rejected and unused pipes, fittings, or valves, including trimmings from
the production of pipes, fittings, or valves, that is reprocessed in a manufacturer's plant after having
been previously processed by the same manufacturer in the production of components by, for example,
injection-moulding or extrusion
3.2.3
compound
homogenous extruded mixture of base polymer (PE) and additives, i.e. anti-oxidants, pigments, carbon
black, UV-stabilizers, at a dosage level necessary for the processing and use of components conforming
to the requirements of this document
3.2.4
base polymer
polymer produced by the material supplier for the manufacture of the compound according to this
document.
3.2.5
fusion compatibility
ability of two similar or dissimilar polyethylene (PE) materials to be fused together to form a joint
which conforms to the performance requirements of this document
3.3 Terms related to material characteristics
3.3.1
lower confidence limit of the predicted hydrostatic strength
σ
LPL
quantity, with the dimensions of stress, which represents the 97,5 % lower confidence limit of the
predicted hydrostatic strength at a temperature θ and time t
Note 1 to entry: It is expressed in Megapascals.
3.3.2
minimum required strength
MRS
value of σ at 20 °C and 50 years, rounded down to the next smaller value of the R10 series when σ
LPL LPL
is below 10 MPa, or to the next lower value of the R20 series when σ is 10 MPa or greater
LPL
[4]
Note 1 to entry: The R10 series conforms to ISO 3 and the R20 series conforms to ISO 497 .
3.3.3
design coefficient
C
coefficient with a value greater than 1 which takes into consideration service conditions as well
as properties of the components of a piping system other than those represented in the lower
confidence limit
3.3.4
design stress
σ
s
allowable stress for a given application at 20 °C, that is derived from the MRS by dividing it by the
design coefficient C, i.e.
MRS
σ =
s
C
Note 1 to entry: It is expressed in Megapascals.
3.3.5
melt mass-flow rate
MFR
value relating to the viscosity of the molten material at a specified temperature and load
Note 1 to entry: It is expressed in grams per 10 min (g/10 min).
3.4 Terms related to service conditions
3.4.1
nominal pressure
PN
numerical designation used for reference purposes related to the mechanical characteristics of the
component of a piping system
Note 1 to entry: For plastic piping systems conveying water, it cor
...