ISO 4437-1

• Abstract:

  This document specifies materials and the general aspects of polyethylene (PE) piping systems in the field of the supply of gaseous fuels. It also specifies the test parameters for the test methods referred to in this document. In conjunction with ISO 4437-2, ISO 4437-3, ISO 4437-4 and ISO 4437-5, this document is applicable to PE pipes, fittings and valves, their joints, and joints with components of PE and other materials intended to be used under the following conditions: a) a maximum operating pressure (MOP) up to and including 10 bar[1], at a reference temperature of 20 °C for design purposes; b) an operating temperature between −20 °C and 40 °C. For operating temperatures between 20 °C and 40 °C, derating coefficients are defined in ISO 4437-5. The ISO 4437 series covers a range of MOPs and gives requirements concerning colours. It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national regulations and installation practices or codes. [1] 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2.

• Status: Not Published
• ICS: 75.200 - Petroleum products and natural gas handling equipment
• ICS: 83.140.30 - Plastics pipes and fittings for non fluid use
• Technical Committee: ISO/TC 138/SC 4 - Plastics pipes and fittings for the supply of gaseous fuels
• Drafting Committee: ISO/TC 138/SC 4/WG 3 - PE Pipe Systems
• Current Stage: 6000 - International Standard under publication
• Start Date: 09-Sep-2026
• Completion Date: 26-Sep-2026

• Revises: ISO 4437-1:2024 - Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 1: General
• Effective Date: 21-Sep-2024

Overview

ISO 4437-1:2026 is the foundational part of the ISO 4437 series, specifying the general aspects and material requirements for polyethylene (PE) piping systems designed for the supply of gaseous fuels. Published by the International Organization for Standardization (ISO), this standard provides the framework for safe, reliable, and efficient design, installation, and operation of PE piping systems in gas supply networks.

The document outlines material properties, general system requirements, and relevant test parameters, ensuring that the pipes, fittings, and valves, as well as their joints, perform reliably under defined conditions. It is applicable to systems designed for gaseous fuels including natural gas, methane, propane, hydrogen, biogas, and mixtures thereof, operating at pressures up to 10 bar and within a temperature range of −20 °C to 40 °C.

Key Topics

• Material Specifications: Defines requirements for PE compounds used in manufacturing pipes, fittings, and valves. This includes details on fusion compatibility, additives, pigmentation, and mechanical properties.
• Operating Conditions: Addresses maximum operating pressure (MOP) up to 10 bar at a reference temperature of 20 °C, with consideration for derating factors in the 20 °C to 40 °C range, as specified in ISO 4437-5.
• Joints and Compatibility: Covers fusion technologies such as butt fusion and electrofusion, ensuring that joints between PE components, or with other materials, maintain system integrity under gas pressure.
• Test Methods: Specifies test parameters to verify material performance, including resistance to pressure, environmental stress cracking, rapid crack propagation, and long-term strength.
• Component Classification: Provides a basis for assigning minimum required strength (MRS) ratings for PE compounds and design coefficients to ensure long-term durability.

Applications

ISO 4437-1 is essential for organizations involved in the design, manufacture, and installation of PE piping systems for gas distribution. Key sectors and use cases include:

• Natural Gas Distribution: Establishes baseline safety and performance criteria for municipal and regional gas supply networks.
• Hydrogen and Gas Mixtures: Supports the transition to renewable gases and hydrogen integration, with information on PE pipe suitability for 100% hydrogen and various gas blends.
• Construction and Utilities: Helps contractors, utilities, and engineers select appropriate materials and components for safe underground gas pipeline installation.
• Product Certification and Compliance: Used by manufacturers and certification bodies to demonstrate conformity with international safety, reliability, and performance standards.

By adhering to ISO 4437-1, stakeholders ensure system compatibility across the supply chain and compliance with national and international regulations.

Related Standards

ISO 4437-1 is part of a broader family of standards governing plastics piping systems for gaseous fuels:

• ISO 4437-2: Specifies requirements for PE pipes.
• ISO 4437-3: Details requirements for PE fittings.
• ISO 4437-4: Covers valve requirements.
• ISO 4437-5: Outlines fitness for purpose testing and derating for temperature effects.
• ISO/TS 4437-7: Provides guidance for assessment of conformity.
• ISO/TS 10839: Recommends practices for design, handling, and installation of PE piping systems.

Supporting standards covering testing and terminology, such as ISO 1133-1 (melt mass-flow rate), ISO 1167 (pressure resistance), and ISO 13953 (tensile strength of PE joints), are also referenced to ensure full compliance and safety in gas pipeline projects.

Conclusion

ISO 4437-1:2026 plays a critical role in the safe supply of gaseous fuels through PE pipes and fittings. Its adoption ensures system interoperability, public safety, and support for innovative energy distribution methods including hydrogen integration. For engineers, designers, and manufacturers, ISO 4437-1 is an indispensable reference for delivering reliable gas piping infrastructure in line with international best practices.

FINAL DRAFT
International
Standard
ISO/FDIS 4437-1
ISO/TC 138/SC 4
Plastics piping systems for
Secretariat: NEN
the supply of gaseous fuels —
Voting begins on:
Polyethylene (PE) —
2026-07-14
Part 1:
Voting terminates on:
2026-09-08
General
Systèmes de canalisations en plastique pour la distribution de
combustibles gazeux — Polyéthylène (PE) —
Partie 1: Généralités
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 4437-1:2026(en) © ISO 2026

FINAL DRAFT
ISO/FDIS 4437-1:2026(en)
International
Standard
ISO/FDIS 4437-1
ISO/TC 138/SC 4
Plastics piping systems for
Secretariat: NEN
the supply of gaseous fuels —
Voting begins on:
Polyethylene (PE) —
Part 1:
Voting terminates on:
General
Systèmes de canalisations en plastique pour la distribution de
combustibles gazeux — Polyéthylène (PE) —
Partie 1: Généralités
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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 Reference number
ISO/FDIS 4437-1:2026(en) © ISO 2026

ii
ISO/FDIS 4437-1:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
3.1 Terms related to material characteristics .3
3.2 Terms related to service conditions .4
3.3 Terms related to joints .5
4 Symbols and abbreviated terms. 5
4.1 Symbols .5
4.2 Abbreviated terms .6
5 Material. 7
5.1 Material of the components .7
5.2 Compound .7
5.2.1 Additives and pigments .7
5.2.2 Colour .7
5.2.3 Characteristics .7
5.3 Fusion compatibility .11
5.4 Classification and designation . . 12
5.5 Design coefficient and design stress . 12
5.6 Change of compound formulation . 12
Annex A (informative) Additional information related to the installation of PE 100-RC systems .13
Annex B (informative) LPG and manufactured gas .15
Annex C (informative) Resistance to rapid crack propagation (RCP) .16
Annex D (informative) Additional information related to the suitability of PE pipe systems for
100% hydrogen and its admixtures with natural gas .18
Bibliography .22

iii
ISO/FDIS 4437-1:2026(en)
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 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 4, Plastics pipes and fittings for the supply of gaseous fuels.
This third edition cancels and replaces the second edition (ISO 4437-1:2024), which has been technically
revised.
The main changes are as follows:
— terms and definitions have been distributed over ISO 4437-1, ISO 4437-2 and ISO 4437-3;
— a conversion and normalisation step has been included in the requirements for the cracked round bar
(CRB) test;
— recommended stress ranges for the CRB and stress levels for the accelerated full notch creep test (AFNCT)
have been added;
— the strip-bend test (ISO 21751) and the crush test (ISO 13955) have been added as alternatives to tests
outlined in ISO 13954;
— a requirement for the electrofusion compatibility has been added;
— information related to the suitability of polyethylene (PE) pipe systems for 100 % hydrogen and its
admixtures with natural gas has been added.
A list of all parts in the ISO 4437 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/FDIS 4437-1:2026(en)
Introduction
The ISO 4437 series specifies the requirements for a piping system and its components made from
polyethylene (PE) compounds, which is intended to be used for the supply of gaseous fuels.
This document covers materials and the general aspects of the plastics piping system.
Requirements and test methods for components of the piping system are specified in ISO 4437-2, ISO 4437-3
and ISO 4437-4.
Characteristics for fitness for purpose of the system are covered in ISO 4437-5. ISO/TS 4437-7 gives guidance
for assessment of conformity.
Recommended practice for design, handling and installation is given in ISO/TS 10839.

v
FINAL DRAFT International Standard ISO/FDIS 4437-1:2026(en)
Plastics piping systems for the supply of gaseous fuels —
Polyethylene (PE) —
Part 1:
General
1 Scope
This document specifies materials and the general aspects of polyethylene (PE) piping systems in the field of
the supply of gaseous fuels.
NOTE For the purpose of this document, the term gaseous fuels includes, for example, natural gas, methane,
butane, propane, hydrogen, manufactured gas, biogas, and mixtures of these gases.
This document also specifies the test parameters for the test methods referred to in this document.
In conjunction with ISO 4437-2, ISO 4437-3, ISO 4437-4 and ISO 4437-5, this document is applicable to PE
pipes, fittings and valves, their joints, and joints with components of PE and other materials intended to be
used under the following conditions:
1)
a) a maximum operating pressure (MOP) up to and including 10 bar , at a design reference temperature of
20 °C;
b) an operating temperature between −20 °C and 40 °C.
For operating temperatures between 20 °C and 40 °C, derating coefficients are specified in ISO 4437-5.
The ISO 4437 series covers a range of MOPs and gives requirements concerning colours.
It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects,
taking into account their particular requirements and any relevant national guidance or regulations 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) and melt volume-flow rate (MVR) of
thermoplastics — Part 1: Standard method
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 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: Immersion method,
liquid pycnometer method and titration method
5 2
1) 1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .

ISO/FDIS 4437-1:2026(en)
ISO 1183-2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density gradient
column method
ISO 4437-2:2026, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 2: Pipes
ISO 4437-3:2026, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 3: Fittings
ISO 4437-4, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 4: Valves
ISO 4437-5, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 5: Fitness for
purpose of the system
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 11413:2019, Plastics pipes and fittings — Preparation of test piece assemblies between a polyethylene (PE)
pipe and an electrofusion fitting
ISO 11414:2009, 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 13479:2022, 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 16770, Plastics — Determination of environmental stress cracking (ESC) of polyethylene — Full-notch creep
test (FNCT)
ISO 16871, Plastics piping and ducting systems — Plastics pipes and fittings — Method for exposure to direct
(natural) weathering
ISO 18488, Polyethylene (PE) materials for piping systems — Determination of strain hardening modulus in
relation to slow crack growth — Test method
ISO 18489:2015, Polyethylene (PE) materials for piping systems — Determination of resistance to slow crack
growth under cyclic loading — Cracked Round Bar test method

ISO/FDIS 4437-1:2026(en)
ISO 18553, Method for the assessment of the degree of pigment or carbon black dispersion in polyolefin pipes,
fittings and compounds
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 4437-2, ISO 4437-3, ISO 11295 and
the following 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 Terms related to material characteristics
3.1.1
lower confidence limit of the predicted hydrostatic strength
σ
LPL
quantity that represents the 97,5 % lower confidence limit of the predicted hydrostatic strength at
temperature θ and time t
Note 1 to entry: It is expressed in megapascals (MPa).
3.1.2
minimum required strength
MRS
value of the lower confidence limit of the predicted hydrostatic strength (3.1.1) at 20 °C and 50 years, rounded
down to the next smaller value of the R10 series or the R20 series
Note 1 to entry: Only compounds with an MRS of 8 MPa or 10 MPa are specified in this document.
Note 2 to entry: The R10 series and the R20 series conform to ISO 3.
Note 3 to entry: It is expressed in megapascals (MPa).
[SOURCE: ISO 12162:2009, 3.3, modified — Note 1 to entry has been removed and replaced with new Notes
1 to 3 to entry.]
3.1.3
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 of
the predicted hydrostatic strength (3.1.1)
3.1.4
design stress
σ
s
allowable stress for a given application at 20 °C that is derived from the minimum required strength, MRS
(3.1.2), by dividing it by the design coefficient, C (3.1.3)
Note 1 to entry: This is demonstrated in the following formula:
MRS
 
s
C
Note 2 to entry: It is expressed in megapascals (MPa).

ISO/FDIS 4437-1:2026(en)
3.1.5
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 minutes (g/10 min).
3.2 Terms related to service conditions
3.2.1
gaseous fuel
substance that reacts exothermically with oxygen, which is in gaseous state at a temperature of 15 °C and at
atmospheric pressure
Note 1 to entry: The energy contained in the fuel is released when it burns.
Note 2 to entry: Typical gaseous fuels are for example natural gas, methane, butane, propane, hydrogen, manufactured
gas, biogas, . , and mixtures of these gases.
Note 3 to entry: Additional information about the suitability of PE pipe systems for hydrogen and its admixtures can
be found in Annex D.
3.2.2
maximum operating pressure
MOP
maximum effective pressure of the fluid in the piping system, which is allowed in continuous use
Note 1 to entry: It is expressed in bar. It takes into account the physical and the mechanical characteristics of the
components of a piping system. It is calculated using the following formula:
20MRS
MOP 
CSDR 1

Note 2 to entry: Research on long-term performance prediction of polyethylene gas distribution systems shows a
possible service life of at least 100 years; see References [19], [20] and [21].
3.2.3
design reference temperature
temperature for which the piping system is designed
Note 1 to entry: It is used as the base for further calculation when designing a piping system or parts of a piping
system for operating temperatures different from the design reference temperature (see ISO 4437-5).
3.2.4
manufactured gas
synthetic gas
gas which has been treated and can contain components that are not typical of natural gas
Note 1 to entry: Manufactured (synthetic) gases can contain substantial amounts of chemical species that are not
typical of natural gases or common species found in atypical proportions as in the case of wet and sour gases.
Note 2 to entry: Manufactured gases fall into two distinct categories, as follows:
a) those that are intended as synthetic or substitute natural gases, and that closely match true natural gases in both
composition and properties;
b) those that, whether or not intended to replace or enhance natural gas in service, do not closely match natural
gases in composition.
Case b) includes gases such as town gas, coke oven gas (undiluted), and LPG/air mixtures. None of which is
compositionally similar to a true natural gas (even though, in the latter case, it can be operationally interchangeable
with natural gas).
ISO/FDIS 4437-1:2026(en)
[SOURCE: ISO 14532:2014, 2.1.1.4]
3.3 Terms related to joints
3.3.1
butt fusion joint
joint made by heating the planed ends of pipes or spigot end fittings, the surfaces of which are fused together
by holding them against a flat heating plate until the polyethylene material reaches fusion temperature,
removing the heating plate quickly and pushing the two softened ends against one another
3.3.2
electrofusion joint
joint between a polyethylene electrofusion socket fitting or electrofusion saddle fitting and a pipe or spigot
end fitting, made by heating the electrofusion fitting by the Joule effect of the heating element incorporated
at their jointing surfaces, causing the material adjacent to them to melt, and the pipe and fitting surfaces to
fuse
3.3.3
fusion compatibility
ability of two similar or dissimilar polyethylene compounds to be fused together to form a joint
4 Symbols and abbreviated terms
4.1 Symbols
For the purposes of this document, the following symbols apply.
A surface area
C design coefficient
d nominal outside diameter
n
E wall thickness (at any point) of a fitting and valve body
e wall thickness (at any point) around the circumference of a component
e minimum wall thickness (at any point)
min
e nominal wall thickness
n
strain hardening modulus
p
L length of a pipe
Δp difference in partial pressure
p critical pressure
c
p critical pressure obtained in full-scale test
c,full-scale
p critical pressure obtained in S4-test
cS4
P permeation coefficient
coef
Q mass flow rate
m
Q permeated volume per time unit
V
ISO/FDIS 4437-1:2026(en)
S pipe series
T wall thickness tolerance
y
t time
θ temperature
ρ density
Δσ stress range
σ design stress
s
σ lower confidence limit of the predicted hydrostatic strength
LPL
4.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
AFNCT accelerated full notch creep test
ANPT accelerated notched pipe test
CRB cracked round bar (test)
DN/OD nominal size
FNCT full notch creep test
LPL lower predicted limit
LPG liquefied petroleum gas
MFR melt mass-flow rate
MOP maximum operating pressure
MRS minimum required strength
NPT notched pipe test
OIT oxidation induction time
PE polyethylene
PLT point load test
RC raised crack resistance
RCP rapid crack propagation
SCG slow crack growth
SDR standard dimension ratio
SHT strain hardening test
ISO/FDIS 4437-1:2026(en)
5 Material
5.1 Material of the components
The pipes, fittings and valves shall be made of a PE compound conforming to this document.
This document includes materials classified as PE 80 and PE 100.
Another type of PE 100, designated as PE 100-RC with enhanced resistance to SCG, is also included in this
document; see Annex A for additional information.
The material described in this document is a compound, which shall be supplied in the form of granules,
suitable for the production of pipes conforming to ISO 4437-2, fittings conforming to ISO 4437-3 or valves
conforming to ISO 4437-4.
5.2 Compound
5.2.1 Additives and pigments
The compound shall be made by adding to the PE base polymer only those additives and pigments (e.g. carbon
black) necessary for the manufacture of pipes, fittings and valves conforming to ISO 4437-2, ISO 4437-3 and
ISO 4437-4, as applicable, and for their fusibility, storage and use.
The carbon black used in the production of black compound shall have an average (primary) particle size of
10 nm to 25 nm. The particle size shall be declared by the carbon black supplier.
All additives and pigments shall be uniformly dispersed.
5.2.2 Colour
The colour of the compound shall be yellow (PE 80), orange (PE 100 and PE 100-RC) or black (PE 80, PE 100
and PE 100-RC).
5.2.3 Characteristics
5.2.3.1 Characteristics of the compound in the form of granules
The compound in the form of granules used for the manufacture of pipes, fittings and valves shall have
characteristics conforming to the requirements given in Table 1.
Table 1 — Characteristics of the compound in the form of granules
Test parameters
a
Characteristic Requirement Test method
Parameter Value
Compound density ≥ 930 kg/m Test temperature 23 °C ISO 1183-1 or
c
ISO 1183-2
b
Number of test pieces Shall conform to
ISO 1183-1 or ISO 1183-
c
d
Oxidation induction time (OIT) ≥ 20 min Test temperature 210 °C ISO 11357-6
(thermal stability)
Test atmosphere Oxygen
Sample mass (15 ± 2) mg
b
Number of test pieces 3
Melt mass-flow rate (MFR) (0,20 ≤ MFR ≤ 1,40) g/10 min Loading mass 5 kg ISO 1133-1
Maximum deviation of ±20 % of the
Test temperature 190 °C
e, f
nominal value
Time 10 min
b
Number of test pieces Shall conform to
ISO 1133-1
ISO/FDIS 4437-1:2026(en)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Test parameters
a
Characteristic Requirement Test method
Parameter Value
b
Volatile content ≤ 350 mg/kg Number of test pieces 1 EN 12099
(equivalent to ≤ 0,035 % by mass)
g b
Water content ≤ 300 mg/kg Number of test pieces 1 ISO 15512
(equivalent to ≤ 0,03 % by mass)
h b
Carbon black content (2,0 to 2,5) % (mass fraction) Number of test pieces Shall conform to ISO 6964
i
ISO 6964
h j
Carbon black dispersion Grade ≤ 3 Preparation of test pieces Free ISO 18553
Rating of appearance A1, A2, A3 or B
b
Number of test pieces Shall conform to
ISO 18553
k j
Pigment dispersion Grade ≤ 3 Preparation of test pieces Free ISO 18553
Rating of appearance A1, A2, A3 or B
b
Number of test pieces Shall conform to
ISO 18553
Resistance to SCG for PE 100- ≥ 53,0 MPa Test temperature 80 °C ISO 18488
p
RC
Thickness 300 µm
l
Strain hardening test (SHT)
Test speed Shall conform to
ISO 18488
b
Number of test pieces Shall conform to
ISO 18488
Resistance to SCG for PE 100- ≥ 1,5 × 10 cycles at an interpolated Test temperature 23 °C ISO 18489
RC stress range (Δσ ) of 12,5 MPa and
Type of test In air
l converted and normalised to a di-
Cracked round bar (CRB) test
ameter of 14 mm and an initial crack
Diameter of test piece 14 mm
m
length of 1,40 mm
Reference stress range 12,5 MPa
Target initial crack length Shall conform to
a * ISO 18489
ini
Waveform/frequency Sinusoid/10 Hz
b
Number of test pieces Shall conform to
ISO 18489
ISO/FDIS 4437-1:2026(en)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Test parameters
a
Characteristic Requirement Test method
Parameter Value
Resistance to SCG for PE 100- ≥ 550 h at an interpolated reference Test temperature 90 °C ISO 16770
RC tensile stress of
p
Environment Lauramine oxide
n, o
4 MPa
Accelerated FNCT
l
Concentration 2 % (mass fraction)
(AFNCT) or
≥ 300 h at an interpolated reference
Test piece dimension 10 mm square
tensile stress of
q
n, o
Failure mode Brittle
5 MPa
b
Number of test pieces Shall conform to
ISO 16770
NOTE 1 Chemical Abstracts Service (CAS) Registry Number® is a trademark of the American Chemical Society (ACS). This information is given
for the convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent products can be
used if they can be shown to lead to the same results.
NOTE 2 Arkopal® N100 is an example of a suitable product available commercially. This information is given for the convenience of users of
this document and does not constitute an endorsement by ISO of this product.
NOTE 3 Dehyton® PL is an example of a suitable product available commercially. This information is given for the convenience of users of this
document and does not constitute an endorsement by ISO of this product.
NOTE 4 The requirement for CRB of 1,5 × 10 cycles is under revision based on the analysis of current round robin performances.
a
Conformity to these requirements shall be proven by the compound manufacturer.
b
The number of test pieces given indicates the number required to establish a value for the characteristic described in this table. The number
of test pieces required for batch release testing and product verification testing should be listed in the manufacturer’s quality plan. Guidance
on assessment of conformity can be found in ISO/TS 4437-7.
c
ISO 1183-3 may be used as alternative. In case of dispute, ISO 1183-1 or ISO 1183-2 shall apply.
d
Test may be carried out at 200 °C or 220 °C provided that a clear correlation has been established. In case of dispute, the reference tempera-
ture shall be 210 °C. The test may be carried out on melt flow extrudate or pellet. In case of dispute, the test shall be carried out on pellet. The
sample thickness is free and not in accordance with ISO 11357-6.
e
Nominal value given by the compound manufacturer.
f
Materials with a nominal value of (0,15 ≤ MFR < 0,20) g/10 min may be introduced. In such case 5.3.1 applies. The lowest MFR value resulting
from the maximum lower deviation of the nominal value is to be not less than 0,15 g/10 min.
g
Volatile or water content shall be measured. In case of dispute, the requirement for water content shall be used, using method B.2 of
ISO 15512. As an alternative method, ISO 760 may be used. The requirement applies to the compound manufacturer at the stage of manufactur-
ing and to the compound user at the stage of processing (if the water content exceeds the limit, drying is required prior to use).
h
Only for black compounds.
i
In case of dispute, Method A “Electric Tube Furnace” shall be used.
j
In case of dispute, the test pieces shall be prepared by the microtome method.
k
Only for non-black compounds.
l
These tests are only performed on PE 100-RC material.
m
For interpolation, CRB test target stress ranges should be chosen between 11,5 MPa and 13,5 MPa. Target stress ranges of 11,5 MPa,
12,2 MPa, 12,8 MPa and 13,5 MPa are recommended. After the test the stress range is to be converted and normalised to a diameter of 14 mm
and an initial crack length of 1,4 mm, in accordance with ISO 18489:2015, Annex A.
n
This requirement correlates to a test in accordance with ISO 16770, with a stress of 4 MPa at 80 °C in nonylphenol ethoxylate with no failure
[22]
for a period of 8 760 h. and may be used as an alternative. Nonylphenol ethoxylate (CAS Registry Number® 9016-45-9) with a trade name of
Arkopal® N100 is used for this test with a concentration for testing of 2 % (mass fraction). In case of dispute, the AFNCT applies.
o
AFNCT test stress levels should be chosen close to the nominal stress in order to avoid long testing times. Test stress levels of 3,7 MPa,
3,9 MPa, 4,2 MPa, 4,5 MPa for the 4 MPa reference stress, and 4,7 MPa, 4,9 MPa and 5,2 MPa and 5,5 MPa for the 5 MPa reference stress are
recommended.
p
Lauramine oxide (CAS Registry Number® 85408-49-7) is commercially available as Dehyton® PL. The dilution of the lauramine oxide in the
product shall be taken into account when calculating the concentration of 2 % (mass fraction). For example, when Dehyton® PL is used, it is
already diluted to 30 % (mass fraction). Therefore, 6,67 % (mass fraction) of Dehyton® PL is needed to obtain 2 % (mass fraction) lauramine
oxide.
q
Test specimens tested at a tensile stress of ≥ 4 MPa (or ≥ 5 MPa) may be terminated once the minimum failure time of 550 h (or 300 h) has
been achieved, in which case there is no failure mode. Test specimens tested at a tensile stress of < 4 MPa (or < 5 MPa) may be terminated once
the interpolated failure time of 550 h (at the reference tensile stress of 4 MPa) or 300 h (at the reference tensile stress of 5 MPa) is achieved,
taking possible scatter in the actual tensile stress into account.
5.2.3.2 Characteristics of the compound in the form of pipe
Unless otherwise specified by the applicable test method, the test pieces shall be conditioned at (23 ± 2) °C
before testing in accordance with Table 2.

ISO/FDIS 4437-1:2026(en)
Table 2 — Characteristics of compound in the form of pipe
Test parameters
a
Characteristic Requirement Test method
Parameter Value
Resistance to gas No failure during the Conditioning period (pipe 1 500 h in air at 23 °C ISO 1167-1 and ISO 1167-2
condensate test period of any test filled with condensate)
piece
End caps Type A
Test temperature 80 °C
Orientation Free
b
Number of test pieces 3
Circumferential (hoop) stress 2,0 MPa
Pipe dimensions: 32 mm
d 3 mm
n
e
n
c
Type of test Synthetic condensate inter-
nal and water external to the
test piece (“liquid-in-water”)
Test period ≥ 20 h
Resistance to The weathered test Preconditioning (weathering): ≥ 3,5 GJ/m ISO 16871
d, e
weathering pieces shall fulfil the cumulative radiant exposure
requirements of the fol-
b
Number of test pieces See below
lowing characteristics,
a), b) and c) below:
f
a)  Decohesion of an elec- a)  Sample prepared in accordance with ISO 11413:2019, Jointing condition 1: a) ISO 13954
trofusion joint 23 °C; ≤ 33 % brittle failure
d : 110 mm SDR 11
n
b)  Hydrostatic strength b)  Shall conform to ISO 4437-2:2026, Table 4 b) ISO 1167-1 and
(1 000 h at 80 °C) d : 32 mm SDR 11 (preferred) or 110 mm SDR 11 ISO 1167-2
n
c)  Elongation at break c)  Shall conform to ISO 4437-2:2026, Table 4 c) ISO 6259-1 and
d : 32 mm SDR 11 (preferred) or 110 mm SDR 11 ISO 6259-3
n
h
Resistance to rapid crack p ≥ 1,5 MOP Pipe dimension d : 250 mm SDR 11 ISO 13477
c n
propagation (RCP) with
Test temperature 0 °C
g
p = 3,6 p + 2,6
(Critical pressure, p ) c cS4
c
Pressurizing fluid air
b
Number of test pieces Shall conform to
ISO 13477
Resistance to SCG for No failure during the Pipe dimension d : 110 mm SDR 11 ISO 13479
n
PE 80 and PE 100 test period of any test
Test temperature 80 °C
i piece
Notched pipe test (NPT)
Internal test pressure for:
PE 80, SDR 11 8,0 bar
PE 100, SDR 11 9,2 bar
Test period ≥ 500 h
Type of test Water internal and water
external to the test piece
(“water-in-water”)
b
Number of test pieces Shall conform to
ISO 13479
Resistance to SCG for No failure during the Pipe dimension d : 110 mm SDR 11 ISO 13479
n
PE 100-RC test period of any test
Test temperature 80 °C
piece
Accelerated notched pipe
j
Internal test pressure for:
test (ANPT)
PE 100-RC, SDR 11 9,2 bar
k
Test period ≥ 300 h
Type of test Water internal and detergent
solution external to the test
l
piece (“water-in-liquid”)
b
Number of test pieces Shall conform to ISO 13479

ISO/FDIS 4437-1:2026(en)
TTabablele 2 2 ((ccoonnttiinnueuedd))
Test parameters
a
Characteristic Requirement Test method
Parameter Value
Determination of the fail- Test to failure: Pipe dimension d : 110 mm SDR 11 ISO 13953
n
ure mode in a tensile test Ductile – pass
Test temperature 23 °C
on a butt-fusion weld Brittle – fail
b
Number of test pieces Shall conform to ISO 13953
NOTE 1 Chemical Abstracts Service (CAS) Registry Number® is a trademark of the American Chemical Society (ACS). This information is given
for the convenience of users of this document and does not constitute an endorsement by ISO of the product named. Equivalent products may be
used if they can be shown to lead to the same results.
NOTE 2 Arkopal® N100 is an example of a suitable product available commercially. This information is given for the convenience of users of
this document and does not constitute an endorsement by ISO of this product.
NOTE 3 Dehyton® PL is an example of a suitable product available commercially. This information is given for the convenience of users of this
document and does not constitute an endorsement by ISO of this product.
a
Conformity to these requirements shall be proven by the compound manufacturer.
b
The number of test pieces given indicates the number required to establish a value for the characteristic described in this table. The number
of test pieces required for batch release testing and product verification testing should be listed in the manufacturer’s quality plan. Guidance
on assessment of conformity can be found in ISO/TS 4437-7.
c
50 % n-decane and 50 % (mass fraction) 1-3-5 trimethylbenzene.
d
Only for non-black compounds.
e 2
For outdoor storage for one year a cumulative radiant exposure of up to 7 GJ/m is valid based on current measurements. Information on
regional levels of UV radiation can be found on web pages of national authorities e.g. meteorological institutes.
f
Alternatively, the strip-bend test according to ISO 21751 or the crush test according to ISO 13955 may be used.
g
If the requirement is not met or S4 test equipment is not available, then (re)testing by using the full-scale test shall be performed in accord-
ance with ISO 13478. In this case: p = p . Further information is given in Annex C.
c c,full-scale
h
For PE 80 materials, smaller pipe diameters may be used for the RCP test. RCP performance is dependent on wall thickness. Pipe of nominal
wall thickness e ≥ 15 mm shall be tested for RCP performance.
n
i
This test is not performed on PE 100-RC materials.
j
The ANPT is specifically for testing PE 100-RC materials.
k
This requirement correlates to a test on 110 mm diameter SDR 11 PE 100-RC pipe in accordance with ISO 13479, at a pressure level of 9,2 bar
[23][24][25]
at 80 °C, water-in-water, with no failure in a test period of 8 760 h, and may be used as an alternative . In case of dispute, the ANPT
applies, see ISO 13479:2022, Annex D.
l
Nonylphenol ethoxylate (CAS Registry Number® 9016-45-9) with a trade name of Arkopal® N100 is used for this test with a concentration for
testing using a 2 % (mass fraction) aqueous solution. This detergent will be replaced by lauramine oxide (CAS Registry Number® 85408–49– ®
7), which is commercially available as Dehyton PL. The requirement for the ANPT using lauramine oxide is under development at the time of
publication of this document.
5.3 Fusion compatibility
5.3.1 The compounds conforming to Table 1 shall be fusible. The compound manufacturer shall check that
the requirement for the failure mode in a tensile test given in Table 2 is fulfilled for a butt fusion joint. The
test sample shall be prepared by using the parameters specified in ISO 11414:2009, Annex A, at an ambient
temperature of (23 ± 2) °C, from pipes both manufactured from that compound.
Fusion compatibility shall be demonstrated by the compound manufacturer for each compound of their own
product range.
For nominal (0,15 ≤ MFR < 0,20) g/10 min pipe compounds, butt fusion compatibility shall be tested in
accordance with ISO 13953 on pipes d ≥ 200 mm and e ≥ 20 mm instead of the tensile test on d 110 mm
n n n
pipes as specified in Table 2.
For nominal (0,15 ≤ MFR < 0,20) g/10 min pipe compounds, electrofusion compatibility shall be tested using
the normal conditions in accordance with ISO 4437-5 on pipes d ≥ 250 mm, SDR 11, with fittings made from
n
PE 100 or PE 100-RC.
5.3.2 Compounds conforming to Table 1 are considered fusible to each other. If requested, the compound
manufacturer shall demonstrate this by checking that the requirement for the failure mode in a tensile
test given in Table 2 is fulfilled for a butt fusion joint prepared by using the parameters as specified in
ISO 11414:2009, Annex A, at an ambient temperature of (23 ± 2) °C from two pipes manufactured from the
compounds from their own range covered by this request.

ISO/FDIS 4437-1:2026(en)
5.4 Classification and designation
Compounds shall be designated by the type of PE material. The minimum required strength (MRS) shall
conform to Table 3 when tested in the form of pipe.
Table 3 — Classification and designation of compounds
Classification by MRS
Designation
MPa
8 PE 80
PE 100
PE 100-RC
The compound shall be evaluated in accordance with ISO 9080 on pipes at least at three temperatures, where
the first temperature is either 20 °C or 23 °C, and the second temperature is 80 °C or alternatively 95 °C, and
the third temperature is free between 30 °C and 70 °C, to find the σ . The MRS value shall be derived from
LPL
the σ and the compound shall be classified by the compound manufacturer in accordance with ISO 12162.
LPL
At the highest tested temperature of 80 °C or 95 °C, there shall be no knee detected in the regression curve
at a time t < 5 000 h.
The conformity of the designation of the compound to the classification given in Table 3 shall be demonstrated
by the compound manufacturer.
Where fittings or valves are manufactured from the same compound as pipes, then the material classification
shall be the same as for pipes.
For the classification of a compound intended only for the manufacture of fittings or valves, test pieces in the
form of extruded pipe made from the compound shall be used.
5.5 Design coefficient and design stress
The design coefficient, C, for pipes, fittings and valves for the supply of gaseous fuels shall be greater than or
equal to 2. The maximum value for the design stress, σ , shall be 4,0 MPa for PE 80 and 5,0 MPa for PE 100
s
and PE 100-RC materials.
A higher design coefficient, C, should be considered for the use of liquefied petroleum gas (LPG) or
manufactured gas (see Annex B).
5.6 Change of compound formulation
Any change in the dosage levels or manufacturing process of the compound affecting its performance can
require a new qualification of the compound.
[16]
NOTE Guidance can be found in ISO/TS 4437-7 and PPI TR-3 .
...

Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
ISO/FDIS 4437-1:2026(en)
Style Definition
...
ISO/TC 138/SC 4
Style Definition
...
Style Definition
...
Secretariat: NEN
Style Definition
...
Date: 2026-03-0506-29
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Plastics piping systems for the supply of gaseous fuels —
Style Definition
...
Polyethylene (PE) —
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Part 1: Style Definition
...
Style Definition
General
...
Style Definition
...
Systèmes de canalisations en plastique pour la distribution de combustibles gazeux — Polyéthylène (PE) —
Style Definition
...
Partie 1: Généralités
Style Definition
...
Partie 1: Généralités
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
FDIS stage
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
Style Definition
...
St l D fi iti
ISO/DISFDIS 4437-1:20252026(en)
Formatted: Default Paragraph Font, French (France)
Formatted: French (France)
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, Formatted: Default Paragraph Font, French (France)
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
Formatted: French (France)
at the address below or ISO’s member body in the country of the requester.
Formatted: Adjust space between Latin and Asian text,
ISO copyright office
Adjust space between Asian text and numbers
CP 401 • Ch. de Blandonnet 8
Formatted
CH-1214 Vernier, Geneva
Formatted: English (United Kingdom)
Phone: + 41 22 749 01 11
E-mail: [e-mail]
Formatted: French (France)
Website: www.iso.org
Formatted: English (United Kingdom)
Published in Switzerland
Formatted: English (United Kingdom)
Formatted: English (United Kingdom)

ii
ISO/FDIS 4437-1:2026(en)
Formatted: Font: 11 pt
Contents Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
Foreword . v
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
3.1 Terms related to material characteristics . 3
3.2 Terms related to service conditions . 4
3.3 Terms related to joints . 5
4 Symbols and abbreviated terms . 6
4.1 Symbols . 6
4.2 Abbreviated terms . 6
5 Material . 7
5.1 Material of the components . 7
5.2 Compound . 7
5.3 Fusion compatibility . 14
5.4 Classification and designation . 15
5.5 Design coefficient and design stress . 15
5.6 Change of compound formulation . 15
Annex A (informative) Additional information related to the installation of PE 100-RC systems16
Annex B (informative) LPG and manufactured gas. 18
Annex C (informative) Resistance to rapid crack propagation (RCP). 19
Annex D (informative) Additional information related to the suitability of PE pipe systems for
100% hydrogen and its admixtures with natural gas . 21
Bibliography . 26

Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 3
3.1 Terms related to material characteristics . 3
3.2 Terms related to service conditions . 4
3.3 Terms related to joints . 5
4 Symbols and abbreviated terms . 5
4.1 Symbols . 5
4.2 Abbreviated terms . 6
5 Material . 7
5.1 Material of the components . 7
5.2 Compound . 7
5.2.1 Additives and pigments . 7
5.2.2 Colour . 7
5.2.3 Characteristics . 7
5.3 Fusion compatibility . 12
iii
ISO/DISFDIS 4437-1:20252026(en)
5.4 Classification and designation . 12
5.5 Design coefficient and design stress . 13
5.6 Change of compound formulation . 13
Annex A (informative) Additional information related to the installation of PE 100-RC systems 14
A.1 Pipe material . 14
A.2 Installation conditions . 15
Annex B (informative) LPG and manufactured gas . 16
Annex C (informative) Resistance to rapid crack propagation (RCP) . 17
C.1 General . 17
C.2 Initiation . 17
C.3 Parameters governing propagation/arrest . 17
C.4 Discussion . 17
C.5 Test methods . 18
Annex D (informative) Additional information related to the suitability of PE pipe systems for
100% hydrogen and its admixtures with natural gas . 19
D.1 General . 19
D.2 Chemical resistance . 19
D.3 Permeation . 20
Bibliography . 23
iv
ISO/FDIS 4437-1:2026(en)
Formatted: Font: 11 pt
Foreword Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
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.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Any trade name used in this document is information given for the convenience of users and does not
Formatted: Default Paragraph Font
constitute an endorsement.
Formatted: Default Paragraph Font
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
Formatted: Default Paragraph Font
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. Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
This document was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
Formatted: Default Paragraph Font
transport of fluids, Subcommittee SC 4, Plastics pipes and fittings for the supply of gaseous fuels.
Formatted: Default Paragraph Font
This third edition cancels and replaces the second edition (ISO 4437-1:2024), which has been technically
Formatted: Default Paragraph Font
revised.
Formatted: Default Paragraph Font
The main changes are as follows:
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
— — terms and definitions have been distributed over ISO 4437-1, ISO 4437-2 and ISO 4437-3;
Formatted: Adjust space between Latin and Asian text,
— — a conversion and normalisation step has been included toin the requirementrequirements for the
Adjust space between Asian text and numbers, Tab
cracked round bar (CRB) test;
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
— — recommended stress ranges for the CRB and stress levels for the accelerated full notch creep test
Formatted: Default Paragraph Font
(AFNCT) have been added;
Formatted: Default Paragraph Font
— — the strip-bend test (ISO 21751) and the crush test (ISO 13955) have been added as alternative
Formatted: Default Paragraph Font
toalternatives to tests outlined in ISO 13954;
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
— — a requirement for the electrofusion compatibility has been added;
Formatted: Default Paragraph Font
— — information related to the suitability of polyethylene (PE) pipe systems for 100 % hydrogen and its
Formatted: Default Paragraph Font
admixtures with natural gas has been added.
Formatted: Default Paragraph Font
A list of all parts in the ISO 4437 series can be found on the ISO website.
Formatted: Default Paragraph Font
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
v
ISO/DISFDIS 4437-1:20252026(en)
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.
vi
ISO/FDIS 4437-1:2026(en)
Formatted: Font: 11 pt
Introduction
The ISO 4437 series specifies the requirements for a piping system and its components made from
Formatted: Default Paragraph Font
polyethylene (PE) compounds, which is intended to be used for the supply of gaseous fuels.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
This document covers materials and the general aspects of the plastics piping system.
Requirements and test methods for components of the piping system are specified in ISO 4437-2, ISO 4437-3
Formatted: Default Paragraph Font
and ISO 4437-4.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Characteristics for fitness for purpose of the system are covered in ISO 4437-5. ISO/TS 4437-7 gives guidance
for assessment of conformity.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Recommended practice for design, handling and installation is given in ISO/TS 10839.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
vii
FINAL DRAFT International Standard ISO/FDIS 4437-1:2026(en)

Plastics piping systems for the supply of gaseous fuels — Polyethylene
(PE) —
Formatted: Main Title 2, None, Adjust space between
Latin and Asian text, Adjust space between Asian text

and numbers
Formatted: Adjust space between Latin and Asian text,
Part 1:
Adjust space between Asian text and numbers
General
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
1 Scope
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
This document specifies materials and the general aspects of polyethylene (PE) piping systems in the field of
Formatted: Adjust space between Latin and Asian text,
the supply of gaseous fuels.
Adjust space between Asian text and numbers
NOTE For the purpose of this document, the term gaseous fuels includeincludes, for example, natural gas, methane, Formatted: Default Paragraph Font
butane, propane, hydrogen, manufactured gas, biogas, and mixtures of these gases.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
ItThis document also specifies the test parameters for the test methods referred to in this document.
Formatted: Default Paragraph Font
In conjunction with ISO 4437-2, ISO 4437-3, ISO 4437-4 and ISO 4437-5, this document is applicable to PE
Formatted: Default Paragraph Font
pipes, fittings and valves, their joints, and joints with components of PE and other materials intended to be
used under the following conditions:
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
1 1)
a) a) a maximum operating pressure, (MOP,) up to and including 10 bar , , at a design reference
Formatted: Default Paragraph Font
temperature of 20 °C;
Formatted: Default Paragraph Font
b) b) an operating temperature between −20 °C and 40 °C.
Formatted: Default Paragraph Font
For operating temperatures between 20 °C and 40 °C, derating coefficients are specified in ISO 4437-5. Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
The ISO 4437 series covers a range of MOPs and gives requirements concerning colours.
Formatted
...
It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects,
Formatted: Default Paragraph Font
taking into account their particular requirements and any relevant national guidance or regulations and
Formatted: Default Paragraph Font
installation practices or codes.
Formatted: Default Paragraph Font
2 Normative references
Formatted
...
Formatted: Default Paragraph Font
The following documents are referred to in the text in such a way that some or all of their content constitutes
Formatted: Default Paragraph Font
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.
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
ISO 1133--1, Plastics — Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of
thermoplastics — Part 1: Standard method Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
Formatted
...
1 5 2
1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
Formatted: Font: 11 pt
1) 5 2
1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
Formatted
...
ISO/DISFDIS 4437-1:20252026(en)
ISO 1167--1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
Formatted: Default Paragraph Font
the resistance to internal pressure — Part 1: General method
ISO 1167--2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
Formatted: Default Paragraph Font
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
Formatted: Default Paragraph Font
method, liquid pycnometer method and titration method
ISO 1183--2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density
Formatted: Default Paragraph Font
gradient column method
ISO 4437--2:2026, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 2: Pipes
Formatted: Default Paragraph Font
ISO 4437--3:2026, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 3:
Formatted: Default Paragraph Font
Fittings
ISO 4437--4, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 4: Valves
Formatted: Default Paragraph Font
ISO 4437--5, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 5: Fitness for
Formatted: Default Paragraph Font
purpose of the system
ISO 6259--1, Thermoplastics pipes — Determination of tensile properties — Part 1: General test method
Formatted: Default Paragraph Font
ISO 6259--3, Thermoplastics pipes — Determination of tensile properties — Part 3: Polyolefin pipes
Formatted: Default Paragraph Font
ISO 6964, Polyolefin pipes and fittings — Determination of carbon black content by calcination and pyrolysis
Formatted: Default Paragraph Font
— Test method
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
Formatted: Default Paragraph Font
thermoplastics materials in pipe form by extrapolation
ISO 11357--6, Plastics — Differential scanning calorimetry (DSC) — Part 6: Determination of oxidation
Formatted: Default Paragraph Font
induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)
ISO 11413:2019, Plastics pipes and fittings — Preparation of test piece assemblies between a polyethylene
Formatted: Default Paragraph Font
(PE) pipe and an electrofusion fitting
ISO 11414:2009, Plastics pipes and fittings — Preparation of polyethylene (PE) pipe/pipe or pipe/fitting test
Formatted: Default Paragraph Font
piece assemblies by butt fusion
ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification,
Formatted: Default Paragraph Font
designation and design coefficient
ISO 13477, Thermoplastics pipes for the conveyance of fluids — Determination of resistance to rapid crack
Formatted: Default Paragraph Font
propagation (RCP) — Small-scale steady-state test (S4 test)
ISO 13478, Thermoplastics pipes for the conveyance of fluids — Determination of resistance to rapid crack
Formatted: Default Paragraph Font
propagation (RCP) — Full-scale test (FST)
ISO 13479:2022, Polyolefin pipes for the conveyance of fluids — Determination of resistance to crack
Formatted: Default Paragraph Font
propagation — Test method for slow crack growth on notched pipes
Formatted: Default Paragraph Font
ISO 13953, Polyethylene (PE) pipes and fittings — Determination of the tensile strength and failure mode of
test pieces from a butt-fused joint
Formatted: FooterPageNumber
Formatted
...
Formatted
...
ISO/FDIS 4437-1:2026(en)
Formatted
...
Formatted
...
Formatted
...
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 Formatted
...
Formatted
...
ISO 15512, Plastics — Determination of water content
Formatted
...
ISO 16770, Plastics — Determination of environmental stress cracking (ESC) of polyethylene — Full-notch
Formatted
...
creep test (FNCT)
Formatted
...
Formatted
ISO 16871, Plastics piping and ducting systems — Plastics pipes and fittings — Method for exposure to direct
...
(natural) weathering
Formatted
...
Formatted
...
ISO 18488, Polyethylene (PE) materials for piping systems — Determination of Strain Hardening
Modulusstrain hardening modulus in relation to slow crack growth — Test method
Formatted
...
Formatted
...
ISO 18489:2015, Polyethylene (PE) materials for piping systems — Determination of resistance to slow crack
Formatted
growth under cyclic loading — Cracked Round Bar test method .
Formatted
...
ISO 18553, Method for the assessment of the degree of pigment or carbon black dispersion in polyolefin pipes,
Formatted
...
fittings and compounds
Formatted
...
EN 12099, Plastics piping systems — Polyethylene piping materials and components — Determination of
Formatted
...
volatile content
Formatted
...
3 Terms and definitions Formatted
...
Formatted
...
For the purposes of this document, the terms and definitions given in ISO 4437-2, ISO 4437-3, ISO 11295 and
Formatted
...
the following apply.
Formatted
...
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
Formatted
...
Formatted
— — ISO Online browsing platform: available at https://www.iso.org/obp
...
Formatted
...
— — IEC Electropedia: available at https://www.electropedia.org/
Formatted
...
3.1 Terms related to material characteristics
Formatted
...
Formatted
...
3.1.1 3.1.1
lower confidence limit of the predicted hydrostatic strength Formatted
...
σ
LPL
Formatted
...
quantity that represents the 97,5 % lower confidence limit of the predicted hydrostatic strength at
Formatted
...
temperature θ and time t
Formatted
...
Note 1 to entry: It is expressed in megapascals (MPa).
Formatted
...
3.1.2 3.1.2 Formatted
...
minimum required strength
Formatted
...
MRS
Formatted
...
value of the lower confidence limit of the predicted hydrostatic strength (3.1.1)(3.1.1) at 20 °C and 50 years,
rounded down to the next smaller value of the R10 series or the R20 series
Formatted
...
Formatted
...
Note 1 to entry: Only compounds with an MRS of 8 MPa or 10 MPa are specified in this document.
Formatted
...
Note 2 to entry: The R10 series and the R20 series conform to ISO 3.
Formatted
...
Note 3 to entry: It is expressed in megapascals (MPa). Formatted
...
Formatted
...
Formatted
...
ISO/DISFDIS 4437-1:20252026(en)
[SOURCE: ISO 12162:2009, 3.3, modified — Note 1 to entry has been removed and replaced with new Notes 1
Formatted: Default Paragraph Font
to 3 to entry.]
Formatted: Default Paragraph Font
3.1.3 3.1.3 Formatted: Default Paragraph Font
design coefficient
Formatted: Default Paragraph Font
C
Formatted: Adjust space between Latin and Asian text,
coefficient with a value greater than 1 which takes into consideration service conditions as well as properties
Adjust space between Asian text and numbers
of the components of a piping system other than those represented in the lower confidence limit of the predicted
hydrostatic strength (3.1.1)(3.1.1) Formatted: Regular Italic, Font: Bold, Not Italic

3.1.4 3.1.4
Formatted: TermNum3, Adjust space between Latin
design stress
and Asian text, Adjust space between Asian text and
σ
s numbers
allowable stress for a given application at 20 °C that is derived from the minimum required strength, MRS
Formatted: Regular Italic, Font: Bold, Not Italic
(3.1.2),(3.1.2), by dividing it by the design coefficient, C (3.1.3)(3.1.3)
Formatted: Regular Sub, Font: Bold, Not Superscript/
Subscript
Note 1 to entry: This is demonstrated in the following formula:
Formatted: Adjust space between Latin and Asian text,
MRS
Adjust space between Asian text and numbers, Tab
σ =
s
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
C
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
𝑀𝑀𝑀𝑀𝑀𝑀
𝜎𝜎 =
s
𝐶𝐶
Note 2 to entry: It is expressed in megapascals (MPa).
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
3.1.5 3.1.5
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
melt mass-flow rate
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
MFR
Formatted: TermNum3, Adjust space between Latin
value relating to the viscosity of the molten material at a specified temperature and load
and Asian text, Adjust space between Asian text and
numbers
Note 1 to entry: It is expressed in grams per 10 minutes (g/10 min).
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
3.2 Terms related to service conditions
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
3.2.1 3.2.1 3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
gaseous fuel
Formatted: Adjust space between Latin and Asian text,
substance that reacts exothermically with oxygen, which is in gaseous state at a temperature of 15 °C and at
Adjust space between Asian text and numbers, Tab
atmospheric pressure
stops: Not at 0.71 cm
Formatted: TermNum3, Adjust space between Latin
Note 1 to entry: The energy contained in the fuel is released when it burns.
and Asian text, Adjust space between Asian text and
numbers
Note 2 to entry: Typical gaseous fuels are for example natural gas, methane, butane, propane, hydrogen, manufactured
gas, biogas, . , and mixtures of these gases. Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
Note 3 to entry: Additional information about the suitability of PE pipe systems for hydrogen and its admixtures can be
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
found in Annex D.Annex D.
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
3.2.2 3.2.2
Formatted: TermNum3, Adjust space between Latin
maximum operating pressure
and Asian text, Adjust space between Asian text and
MOP
numbers
maximum effective pressure of the fluid in the piping system, which is allowed in continuous use
Formatted: FooterPageNumber
ISO/FDIS 4437-1:2026(en)
Note 1 to entry: It is expressed in bar. It takes into account the physical and the mechanical characteristics of the
Formatted: Adjust space between Latin and Asian text,
components of a piping system. It is calculated using the following formula:
Adjust space between Asian text and numbers, Tab
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
20× MRS
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
MOP=
C×−SDR 1
( )
20 ×  𝑀𝑀𝑀𝑀𝑀𝑀
𝑀𝑀𝑀𝑀𝑀𝑀 =
𝐶𝐶 ×  (𝑀𝑀𝑆𝑆𝑀𝑀 −1)
Note 2 to entry: Research on long-term performance prediction of polyethylene gas distribution systems shows a
Formatted: Adjust space between Latin and Asian text,
possible service life of at least 100 years; see References [19], [20] and [21]. [19],[20]and[21].
Adjust space between Asian text and numbers, Tab
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
3.2.3 3.2.3
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
design reference temperature
Formatted: TermNum3, Adjust space between Latin
temperature for which the piping system is designed
and Asian text, Adjust space between Asian text and
numbers
Note 1 to entry: It is used as the base for further calculation when designing a piping system or parts of a piping system
for operating temperatures different from the design reference temperature (see ISO 4437-5). Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
3.2.4 3.2.4
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
manufactured gas
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
synthetic gas
Formatted: Default Paragraph Font
gas which has been treated and can contain components that are not typical of natural gas
Formatted: Default Paragraph Font
Note 1 to entry: Manufactured (synthetic) gases can contain substantial amounts of chemical species that are not typical
Formatted: Default Paragraph Font
of natural gases or common species found in atypical proportions as in the case of wet and sour gases.
Formatted: TermNum3, Adjust space between Latin
and Asian text, Adjust space between Asian text and
Note 2 to entry: Manufactured gases fall into two distinct categories, as follows:
numbers
a) a) those that are intended as synthetic or substitute natural gases, and that closely match true natural gases
Formatted: Adjust space between Latin and Asian text,
in both composition and properties;
Adjust space between Asian text and numbers, Tab
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
b) b) those that, whether or not intended to replace or enhance natural gas in service, do not closely match
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
natural gases in composition.
Case b) includes gases such as town gas, coke oven gas (undiluted), and LPG/air mixtures. None of which is
compositionally similar to a true natural gas (even though, in the latter case, it can be operationally interchangeable with
natural gas).
[SOURCE: ISO 14532:2014, 2.1.1.4]
Formatted: Default Paragraph Font
Formatted: Default Paragraph Font
3.3 Terms related to joints
Formatted: Default Paragraph Font
3.3.1 3.3.1
Formatted: Default Paragraph Font
butt fusion joint
Formatted: Adjust space between Latin and Asian text,
joint made by heating the planed ends of pipes or spigot end fittings, the surfaces of which are fused together
Adjust space between Asian text and numbers
by holding them against a flat heating plate until the polyethylene material reaches fusion temperature,
removing the heating plate quickly and pushing the two softened ends against one another
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers, Tab
3.3.2 3.3.2
stops: Not at 0.71 cm
electrofusion joint
Formatted: TermNum3, Adjust space between Latin
joint between a polyethylene electrofusion socket fitting or electrofusion saddle fitting and a pipe or spigot
and Asian text, Adjust space between Asian text and
end fitting, made by heating the electrofusion fitting by the Joule effect of the heating element incorporated at
numbers
their jointing surfaces, causing the material adjacent to them to melt, and the pipe and fitting surfaces to fuse
Formatted: FooterPageNumber
ISO/DISFDIS 4437-1:20252026(en)
Formatted
...
Formatted
...
3.3.3 3.3.3
Formatted
...
fusion compatibility
Formatted Table
ability of two similar or dissimilar polyethylene compounds to be fused together to form a joint .
Formatted
...
4 Symbols and abbreviated terms
Formatted
...
Formatted
4.1 Symbols .
Formatted
...
For the purposes of this document, the following symbols apply.
Formatted
...
Formatted
A surface area .
Formatted
...
C design coefficient
Formatted
...
dn nominal outside diameter
Formatted
...
E wall thickness (at any point) of a fitting and valve body
Formatted
...
e wall thickness (at any point) around the circumference of a component
Formatted
...
emin minimum wall thickness (at any point)
Formatted
...
e nominal wall thickness
n
Formatted
...
strain hardening modulus
p
Formatted
...
L length of a pipe
Formatted
...
Δp difference in partial pressure Formatted
...
p critical pressure Formatted
c
...
Formatted
p critical pressure obtained in full-scale test .
c,full-scale
Formatted
...
p critical pressure obtained in S4-test
cS4
Formatted
...
Pcoef permeation coefficient
Formatted
...
Q mass flow rate
m
Formatted
...
Q permeated volume per time unit
V
Formatted
...
S pipe series
Formatted
...
Ty wall thickness tolerance
Formatted
...
t time
Formatted
...
θ temperature
Formatted
...
ρ density
Formatted
...
Δσ stress range Formatted
...
Formatted
σ design stress
s .
Formatted
...
σ lower confidence limit of the predicted hydrostatic strength
LPL
Formatted
...
4.2 Abbreviated terms
Formatted
...
Formatted
...
For the purposes of this document, the following abbreviated terms apply.
Formatted
...
AFNCT accelerated full notch creep test
Formatted Table
...
ANPT accelerated notched pipe test
Formatted
...
Formatted
...
ISO/FDIS 4437-1:2026(en)
Formatted
...
Formatted
...
CRB cracked round bar (test)
Formatted
...
DN/OD nominal size
Formatted
...
FNCT full notch creep test
Formatted
...
LPL lower predicted limit
Formatted
...
LPG liquefied petroleum gas
Formatted
...
MFR melt mass-flow rate
Formatted
...
MOP maximum operating pressure
Formatted
...
MRS minimum required strength
Formatted
...
NPT notched pipe test Formatted
...
OIT oxidation induction time Formatted
...
Formatted
PE polyethylene .
Formatted
...
PLT point load test
Formatted
...
RC raised crack resistance
Formatted
...
RCP rapid crack propagation
Formatted
...
SCG slow crack growth
Formatted
...
SDR standard dimension ratio
Formatted
...
SHT strain hardening test
Formatted
...
Formatted
...
5 Material
Formatted
...
5.1 Material of the components
Formatted
...
Formatted
The pipes, fittings and valves shall be made of a PE compound conforming to this document. .
Formatted
...
This document includes materials classified as PE 80 and PE 100.
Formatted
...
Another type of PE 100, designated as PE 100-RC with enhanced resistance to SCG, is also included in this Formatted
...
document; see Annex AAnnex A for additional information.
Formatted
...
Formatted
...
The material described in this document is a compound, which shall be supplied in the form of granules,
suitable for the production of pipes conforming to ISO 4437-2, fittings conforming to ISO 4437-3 or valves
Formatted
...
conforming to ISO 4437-4.
Formatted
...
Formatted
5.2 Compound
...
Formatted
...
5.2.1 Additives and pigments
Formatted
...
The compound shall be made by adding to the PE base polymer only those additives and pigments (e.g. carbon
Formatted
...
black) necessary for the manufacture of pipes, fittings and valves conforming to ISO 4437-2, ISO 4437-3 and
Formatted
...
ISO 4437-4, as applicable, and for their fusibility, storage and use.
Formatted
...
The carbon black used in the production of black compound shall have an average (primary) particle size of
Formatted
...
10 nm to 25 nm. The particle size shall be declared by the carbon black supplier.
Formatted
...
All additives and pigments shall be uniformly dispersed. Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
ISO/DISFDIS 4437-1:20252026(en)
Formatted
...
Formatted
...
Formatted
...
5.2.2 Colour
Formatted
...
The colour of the compound shall be yellow (PE 80), orange (PE 100 and PE 100-RC) or black (PE 80, PE 100
Formatted
...
and PE 100-RC).
Formatted
...
5.2.3 Characteristics
Formatted
...
Formatted Table
5.2.3.1 Characteristics of the compound in the form of granules
...
Formatted
...
The compound in the form of granules used for the manufacture of pipes, fittings and valves shall have
Formatted
...
characteristics conforming to the requirements given in Table 1.Table 1.
Formatted
...
Table 1 — Characteristics of the compound in the form of granules
Formatted
...
Test parameters Formatted
Requirement Test .
Characteristic
a a
Requirement method
Parameter Value Formatted
...
ISO 1183-1 or Formatted
Compound density ≥ 930 kg/m Test temperature 23 °C .
c c
ISO 1183-2 2
b Formatted
Number of test pieces Shall conform to .
ISO 1183-1 or
Formatted
c c .
ISO 1183-2 2
Formatted
...
d
Oxidation induction time ≥ 20 min Test temperature 210 °C ISO 11357-6
(OIT) (thermal stability)
Formatted
...
Test atmosphere Oxygen
Formatted
...
Sample mass (15 ± 2) mg
Formatted
...
b
Number of test pieces 3
Formatted
...
Melt mass-flow rate (MFR) (0,20 ≤ MFR ≤ 1,40) g/10 min Loading mass 5 kg ISO 1133-1
Maximum deviation of ±20 % of the Formatted
...
Test temperature 190 °C
e, f
nominal value
Formatted
...
Time 10 min
Formatted
b .
Number of test pieces Shall conform to
ISO 1133-1
Formatted
...
b
Volatile content ≤ 350 mg/kg Number of test pieces 1 EN 12099
Formatted
...
(equivalent to ≤ 0,035 % by mass)
Formatted
...
g b
Water content ≤ 300 mg/kg Number of test pieces 1 ISO 15512
Formatted
...
(equivalent to ≤ 0,03 % by mass)
Formatted
...
h b
Carbon black content (2,0 to 2,5) % (mass fraction) Number of test pieces Shall conform to ISO 6964
i i
ISO 6964 6964 Formatted
...
h j
Carbon black dispersion Grade ≤ 3 Preparation of test pieces Free ISO 18553
Formatted
...
Rating of appearance A1, A2, A3 or
b
Number of test pieces Shall conform to Formatted
...
B
ISO 18553
Formatted
...
k j
Pigment dispersion Grade ≤ 3 Preparation of test pieces Free ISO 18553
Formatted
...
Rating of appearance A1, A2, A3 or
b
Number of test pieces Shall conform to
B
Formatted
ISO 18553 .
Formatted
...
Resistance to SCG for PE 100- ≥ 53,0 MPa Test temperature 80 °C ISO 18488
RC
Formatted
Thickness 300 µm .
l
Strain hardening test (SHT)
Formatted
Test speed Shall conform to .
ISO 18488
Formatted
...
b
Number of test pieces Shall conform to
Formatted
...
ISO 18488
Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
Formatted
...
ISO/FDIS 4437-1:2026(en)
Formatted: FooterPageNumber
ISO/DISFDIS 4437-1:20252026(en)
Formatted
...
Formatted
...
Table 1 Continued
Formatted
...
Formatted Table
Test parameters
...
a
Characteristic Requirement Test method
Formatted
...
Parameter Value
Formatted
6 .
Resistance to SCG for PE 100- ≥ 1,5 × 10 cyc
...