SIST EN ISO 16486-3:2025

Plastics piping systems for the supply of gaseous fuels - Unplasticized polyamide (PA-U) piping systems with fusion jointing and mechanical jointing - Part 3: Fittings (ISO 16486-3:2025)

This document specifies the physical and mechanical properties of fittings made from unplasticized polyamide (PA-U) in accordance with ISO 16486-1, intended to be buried and used for the supply of gaseous fuels.
It also specifies the test parameters for the test methods to which it refers.
The ISO 16486 series is applicable to PA-U piping systems, the components of which are connected by fusion jointing and/or mechanical jointing.
In particular, this document lays down dimensional characteristics and requirements for the marking of fittings.
In conjunction with the other parts of the ISO 16486 series, this document is applicable to PA-U fittings, their joints, joints with components of PA-U and joints with mechanical fittings of other materials, and to the following fitting types:
—     fusion fittings (electrofusion fittings and butt fusion fittings), and
—     transition fittings.

Kunststoff-Rohrleitungssysteme für die Gasversorgung - Rohrleitungssysteme aus weichmacherfreiem Polyamid (PA-U) mit Schweißverbindungen und mechanischen Verbindungen - Teil 3: Formstücke (ISO 16486-3:2025)

Dieses Dokument legt die physikalischen und mechanischen Eigenschaften von Formstücken fest, die nach ISO 16486 1 aus weichmacherfreiem Polyamid (PA-U) hergestellt und dafür vorgesehen sind, unterirdisch verlegt und für die Gasversorgung verwendet zu werden.
Es legt auch die Prüfparameter für die Prüfverfahren fest, auf die es sich bezieht.
Die Normenreihe ISO 16486 ist anwendbar für PA-U-Rohrleitungssysteme, deren Komponenten durch Schweißverbindungen und/oder mechanische Verbindungen zusammengefügt werden.
Dieses Dokument legt insbesondere Maßeigenschaften und Anforderungen an die Kennzeichnung von Formstücken fest.
Zusammen mit den anderen Teilen der Normenreihe ISO 16486 ist dieses Dokument anwendbar für PA-U-Formstücke, deren Verbindungen, Verbindungen mit Komponenten aus PA-U und Verbindungen mit mechanischen Formstücken aus anderen Werkstoffen sowie für die folgenden Arten von Formstücken:
   Schweißformstücke (Heizwendelschweiß- und Stumpfschweiß-Formstücke); und
   Übergangsformstücke.

Systèmes de canalisations en matières plastiques pour la distribution de combustibles gazeux - Systèmes de canalisations en polyamide non plastifié (PA-U) avec assemblages par soudage et assemblages mécaniques - Partie 3: Raccords (ISO 16486-3:2025)

Le présent document spécifie les propriétés physiques et mécaniques des raccords en polyamide non plastifié (PA-U) conformément à l’ISO 16486-1, destinés à être enterrés et utilisés pour la distribution de combustibles gazeux.
Il spécifie également les paramètres d’essai pour les méthodes d’essai auxquelles il fait référence.
La série ISO 16486 s’applique aux systèmes de canalisations en PA-U dont les composants sont raccordés par des assemblages par soudage et/ou par des assemblages mécaniques.
En particulier, le présent document définit les caractéristiques dimensionnelles et les exigences pour le marquage des raccords.
En conjonction avec les autres parties de la série ISO 16486, le présent document s’applique aux raccords en PA-U, à leurs assemblages, aux assemblages avec des composants en PA-U, aux assemblages avec des raccords mécaniques fabriqués en d’autres matières, ainsi qu’avec les types de raccords suivants:
—     les raccords soudables (raccords électrosoudables et raccords par soudage bout à bout), et
—     les raccords de transition.

Cevni sistemi iz polimernih materialov za oskrbo s plinastimi gorivi - Cevni sistemi iz nemehčanega poliamida (PA-U) z zvari in mehanskimi spoji - 3. del: Fitingi (ISO 16486-3:2025)

Ta dokument določa fizikalne in mehanske lastnosti fitingov iz nemehčanega poliamida (PA-U) v skladu s standardom ISO 16486-1, ki so predvideni za vkop in uporabo za namene oskrbe s plinastimi gorivi.
Določa tudi preskusne parametre za preskusne metode, na katere se sklicuje.
Skupina standardov ISO 16486 se uporablja za cevne sisteme iz nemehčanega poliamida, sestavni deli katerih so povezani z zvari in/ali mehanskimi spoji.
Ta dokument zlasti določa dimenzijske lastnosti in zahteve za označevanje fitingov.
V povezavi z drugimi deli skupine standardov ISO 16486 se ta dokument uporablja za fitinge iz nemehčanega poliamida, njihove spoje, spoje s komponentami iz nemehčanega poliamida in spoje z mehanskimi fitingi iz drugih materialov ter za naslednje vrste fitingov:
– fuzijske fitinge (elektrofuzijske fitinge in soležno taljene fitinge) in
– prehodne fitinge.

General Information

• Status: Published
• Public Enquiry End Date: 29-Jun-2024
• Publication Date: 30-Jan-2025
• ICS: 75.200 - Petroleum products and natural gas handling equipment
• ICS: 83.140.30 - Plastics pipes and fittings for non fluid use
• Technical Committee: PCV - Plastic pipes, fittings and valves
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 28-Jan-2025
• Due Date: 04-Apr-2025
• Completion Date: 31-Jan-2025
• Ref Project: EN ISO 16486-3:2025 - Plastics piping systems for the supply of gaseous fuels - Unplasticized polyamide (PA-U) piping systems with fusion jointing and mechanical jointing - Part 3: Fittings (ISO 16486-3:2025)

Relations

• Amended By: SIST EN ISO 16486-3:2025/A11:2025 - Plastics piping systems for the supply of gaseous fuels - Unplasticized polyamide (PA-U) piping systems with fusion jointing and mechanical jointing - Part 3: Fittings
• Effective Date: 25-Jun-2025
• Revises: SIST EN ISO 16486-3:2020 - Plastics piping systems for the supply of gaseous fuels - Unplasticized polyamide (PA-U) piping systems with fusion jointing and mechanical jointing - Part 3: Fittings (ISO 16486-3:2020)
• Effective Date: 25-Oct-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2025
Cevni sistemi iz polimernih materialov za oskrbo s plinastimi gorivi - Cevni sistemi
iz nemehčanega poliamida (PA-U) z zvari in mehanskimi spoji - 3. del: Fitingi (ISO
16486-3:2025)
Plastics piping systems for the supply of gaseous fuels - Unplasticized polyamide (PA-U)
piping systems with fusion jointing and mechanical jointing - Part 3: Fittings (ISO 16486-
3:2025)
Kunststoff-Rohrleitungssysteme für die Gasversorgung - Rohrleitungssysteme aus
weichmacherfreiem Polyamid (PA-U) mit Schweißverbindungen und mechanischen
Verbindungen - Teil 3: Formstücke (ISO 16486-3:2025)
Systèmes de canalisations en matières plastiques pour la distribution de combustibles
gazeux - Systèmes de canalisations en polyamide non plastifié (PA-U) avec
assemblages par soudage et assemblages mécaniques - Partie 3: Raccords (ISO 16486
-3:2025)
Ta slovenski standard je istoveten z: EN ISO 16486-3:2025
ICS:
75.200 Oprema za skladiščenje Petroleum products and
nafte, naftnih proizvodov in natural gas handling
zemeljskega plina equipment
83.140.30 Polimerne cevi in fitingi za Plastics pipes and fittings for
snovi, ki niso tekočine non fluid use
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16486-3
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2025
EUROPÄISCHE NORM
ICS 75.200; 83.140.30 Supersedes EN ISO 16486-3:2020
English Version
Plastics piping systems for the supply of gaseous fuels -
Unplasticized polyamide (PA-U) piping systems with
fusion jointing and mechanical jointing - Part 3: Fittings
(ISO 16486-3:2025)
Systèmes de canalisations en matières plastiques pour Kunststoff-Rohrleitungssysteme für die Gasversorgung
la distribution de combustibles gazeux - Systèmes de - Rohrleitungssysteme aus weichmacherfreiem
canalisations en polyamide non plastifié (PA-U) avec Polyamid (PA-U) mit Schweißverbindungen und
assemblages par soudage et assemblages mécaniques - mechanischen Verbindungen - Teil 3: Formstücke (ISO
Partie 3: Raccords (ISO 16486-3:2025) 16486-3:2025)
This European Standard was approved by CEN on 21 December 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16486-3:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 16486-3:2025) has been prepared by Technical Committee ISO/TC 138
"Plastics pipes, fittings and valves for the transport of fluids" in collaboration with Technical Committee
CEN/TC 155 “Plastics piping systems and ducting systems” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2025, and conflicting national standards shall be
withdrawn at the latest by July 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 16486-3:2020.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 16486-3:2025 has been approved by CEN as EN ISO 16486-3:2025 without any
modification.
International
Standard
ISO 16486-3
Third edition
Plastics piping systems for
2025-01
the supply of gaseous fuels —
Unplasticized polyamide (PA-U)
piping systems with fusion jointing
and mechanical jointing —
Part 3:
Fittings
Systèmes de canalisations en matières plastiques pour la
distribution de combustibles gazeux — Systèmes de canalisations
en polyamide non plastifié (PA-U) avec assemblages par soudage
et assemblages mécaniques —
Partie 3: Raccords
Reference number
ISO 16486-3:2025(en) © ISO 2025

ISO 16486-3:2025(en)
© ISO 2025
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]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 16486-3:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Material. 3
4.1 PA-U compound .3
4.2 Material for non-unplasticized polyamide parts .3
4.2.1 General .3
4.2.2 Metal parts .3
4.2.3 Elastomers .3
4.2.4 Other materials .4
5 General characteristics . 4
5.1 Appearance .4
5.2 Design .4
5.3 Colour .4
5.4 Electrical characteristics for electrofusion fittings .4
5.5 Appearance of factory-made fusion joints .4
5.6 Fusion compatibility .5
5.7 Appearance of transition fittings.5
6 Geometrical characteristics . 5
6.1 Measurement of dimensions .5
6.2 Dimensions of electrofusion sockets .5
6.2.1 Diameters and lengths of electrofusion sockets .5
6.2.2 Wall thickness .5
6.3 Dimensions of spigot end fittings .7
6.4 Dimensions of tapping tees .9
6.5 Dimensions of transition fittings to other materials .9
7 Mechanical characteristics . 9
7.1 General .9
7.2 Conditioning.10
7.3 Mechanical requirements .10
7.4 Additional requirements for transition fittings . 12
8 Physical characteristics .12
8.1 Conditioning. 12
8.2 Requirements . 12
9 Chemical resistance of fittings in contact with chemicals .13
10 Performance requirements . .13
11 Marking . .13
11.1 General . 13
11.2 Minimum required marking of fittings . 13
11.3 Additional information required on fitting or label .14
11.4 Fusion system recognition .14
12 Delivery conditions . 14
Annex A (informative) Examples of typical terminal connections for electrofusion .15
Annex B (normative) Short-term pressure test method . 17
Annex C (normative) Tensile test fitting/pipe assemblies . 19
Bibliography .20

iii
ISO 16486-3:2025(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, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 155, Plastics piping
systems and ducting systems, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 16486-3:2020), which has been technically
revised.
The main changes are as follows:
— the references in the Introduction have been updated;
— a Note has been added in the Introduction for information related to the suitability of PA-U pipe systems
for 100 % hydrogen and its admixtures with natural gas;
— ISO 3183 has been added to the normative references;
— in Table 3, row “315”, cut back length, the value “758” has been corrected to “75”;
— a Note has been added in 7.4 for the testing of leaktightness under pressure with air/nitrogen, appropriate
for all gaseous fuels (e.g. methane and hydrogen);
— the Note in 11.3 concerning coding of traceability data has been changed and in 11.4, reference to
ISO 12176-5 has been made;
— in Figure A.1, the illustration is replaced by a sketch that shows the value h (= height of the active part).
A list of all parts in the ISO 16486 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 16486-3:2025(en)
Introduction
This document specifies the requirements for a piping system and its components made from unplasticized
polyamide (PA-U), which is intended to be used for the supply of gaseous fuels.
NOTE 1 Additional information about the suitability of PA-U pipe systems for hydrogen and its admixtures is given
in ISO 16486-1:2023, Annex D.
Requirements and test methods for material and components of the piping system, are specified in
ISO 16486-1, ISO 16486-2 and ISO 16486-4.
Characteristics for fitness for purpose of the system and generic fusion parameters are covered in
ISO 16486-5.
Recommended practice for installation is given in ISO 16486-6, which will not be implemented as a European
Standard under the Vienna Agreement.
[3]
NOTE 2 Recommended practice for installation is also given in CEN/TS 12007-6, which has been prepared by
Technical Committee CEN/TC 234, Gas infrastructure.
Assessment of conformity of the system is covered in ISO/TS 16486-7 .
ISO 16486-1, ISO 16486-2, ISO 16486-3, ISO 16486-5, ISO 16486-6, ISO/TS 16486-7 and ISO/TS 16486-8
have been prepared by ISO/TC 138/SC 4. ISO 16486-4 has been prepared by ISO/TC 138/SC 7.

v
International Standard ISO 16486-3:2025(en)
Plastics piping systems for the supply of gaseous fuels —
Unplasticized polyamide (PA-U) piping systems with fusion
jointing and mechanical jointing —
Part 3:
Fittings
1 Scope
This document specifies the physical and mechanical properties of fittings made from unplasticized polyamide
(PA-U) in accordance with ISO 16486-1, intended to be buried and used for the supply of gaseous fuels.
It also specifies the test parameters for the test methods to which it refers.
The ISO 16486 series is applicable to PA-U piping systems, the components of which are connected by fusion
jointing and/or mechanical jointing.
In particular, this document lays down dimensional characteristics and requirements for the marking of
fittings.
In conjunction with the other parts of the ISO 16486 series, this document is applicable to PA-U fittings,
their joints, joints with components of PA-U and joints with mechanical fittings of other materials, and to the
following fitting types:
— fusion fittings (electrofusion fittings and butt fusion fittings), and
— transition fittings.
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 291, Plastics — Standard atmospheres for conditioning and testing
ISO 307, Plastics — Polyamides — Determination of viscosity number
ISO 1133-2, Plastics — Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of
thermoplastics — Part 2: Method for materials sensitive to time-temperature history and/or moisture
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 1167-4, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the
resistance to internal pressure — Part 4: Preparation of assemblies
ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions
ISO 3183, Petroleum and natural gas industries — Steel pipe for pipeline transportation systems
ISO 4433-1, Thermoplastics pipes — Resistance to liquid chemicals — Classification — Part 1: Immersion test method

ISO 16486-3:2025(en)
ISO 11922-1, Thermoplastics pipes for the conveyance of fluids — Dimensions and tolerances — Part 1: Metric series
ISO 13950, Plastics pipes and fittings — Automatic recognition systems for electrofusion joints
ISO 13951, Plastics piping systems — Test method for the resistance of plastic pipe/pipe or pipe/fitting
assemblies to tensile loading
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 13955, Plastics pipes and fittings — Crushing decohesion test for polyethylene (PE) electrofusion assemblies
ISO 13956, Plastics pipes and fittings — Decohesion test of polyethylene (PE) saddle fusion joints — Evaluation
of ductility of fusion joint interface by tear test
ISO 13957, Plastics pipes and fittings — Polyethylene (PE) tapping tees — Test method for impact resistance
ISO 16486-1, Plastics piping systems for the supply of gaseous fuels — Unplasticized polyamide (PA-U) piping
systems with fusion jointing and mechanical jointing — Part 1: General
ISO 16486-2, Plastics piping systems for the supply of gaseous fuels — Unplasticized polyamide (PA-U) piping
systems with fusion jointing and mechanical jointing — Part 2: Pipes
ISO 16486-5, Plastics piping systems for the supply of gaseous fuels — Unplasticized polyamide (PA-U) piping
systems with fusion jointing and mechanical jointing — Part 5: Fitness for purpose of the system
ISO 17778, Plastics piping systems — Fittings, valves and ancillaries — Determination of gaseous flow rate/
pressure drop relationships
ISO 17885, Plastics piping systems — Mechanical fittings for pressure piping systems — Specifications
EN 682, Elastomeric seals - Materials requirements for seals used in pipes and fittings carrying gas and
hydrocarbon fluids
IEC 60529, Degrees of protection provided by enclosures (IP Code)
API 5L, Specification for Line Pipe
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16486-1 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
electrofusion socket fitting
polyamide (PA-U) fitting which contains one or more integral heating elements that are capable of
transforming electrical energy into heat to realize a fusion joint with a spigot end and/or a pipe
3.2
electrofusion saddle fitting
unplasticized polyamide (PA-U) fitting which contains one or more integral heating elements that are
capable of transforming electrical energy into heat to realize fusion onto a pipe

ISO 16486-3:2025(en)
3.3
tapping tee
electrofusion saddle fitting (3.2) (top loading or wraparound) which contains an integral cutter, used to cut
through the wall of the main pipe, and which holds the coupon inside the cutter
Note 1 to entry: The cutter remains in the body of the saddle after installation.
3.4
spigot end fitting
unplasticized polyamide (PA-U) fitting where the outside diameter of the spigot length is equal to the
nominal outside diameter, d , of the corresponding pipe
n
3.5
transition fitting
factory made fitting that makes a transition joint between an unplasticized polyamide (PA-U) piping and a
metallic pipe
Note 1 to entry: The metallic parts of the fitting may be assembled to metallic pipes by screw threads, compression
joints, welded or flanged connections. The fitting can allow for either a dismountable or permanently assembled joint.
In some cases, the supporting ring can also act as a grip ring.
4 Material
4.1 PA-U compound
The fittings shall be made from virgin material.
The compound from which the fittings are made shall be in accordance with ISO 16486-1.
4.2 Material for non-unplasticized polyamide parts
4.2.1 General
The materials and constituent elements used in making the fitting shall be resistant to the external and
internal environments in which they are intended to be used:
1) during storage;
2) under the effect of the gaseous fuels being conveyed; and
3) taking account of the service environment and operating conditions.
Fittings materials, including elastomers, greases and lubricants in contact with the PA-U pipe, shall not
adversely affect pipe performance or initiate stress cracking.
In all cases, fitness for purpose of the system of the components shall be demonstrated.
4.2.2 Metal parts
All parts susceptible to corrosion shall be adequately protected.
When dissimilar metallic materials are used which can be in contact with moisture, steps shall be taken to
avoid galvanic corrosion.
Metals and materials produced by corrosion shall not affect the long-term performance of the pipe/fitting.
4.2.3 Elastomers
Elastomeric materials used for the manufacture of seals shall be in accordance with EN 682.

ISO 16486-3:2025(en)
4.2.4 Other materials
Greases or lubricants shall not exude on to the fusion areas, and shall not affect the long-term performance
of the pipe/fitting.
5 General characteristics
5.1 Appearance
When viewed without magnification, the internal and external surfaces of the fitting shall be smooth, clean
and free from scoring, cavities and other surface defects such as would prevent conformity of the fitting to
this document.
No component of the fitting shall show any signs of damage, scratches, pitting, bubbles, blisters, inclusions
or cracks to an extent that would prevent conformity of the fittings to the requirements of this document.
5.2 Design
The design of the fitting shall be such that, when assembling the fitting onto the pipe, spigot ends or other
components, the electrical coils and/or seals and other functional parts (e.g. grippers) are not displaced.
5.3 Colour
The colour of fittings shall be yellow or black.
5.4 Electrical characteristics for electrofusion fittings
The electrical protection to be provided by the system depends on the voltage and the current used and on
the characteristics of the electric power.
For voltages greater than 25 V, direct human contact with the energized parts shall not be possible when the
fitting is in the fusion cycle during assembly in accordance with the instructions of the manufacturer of the
fittings and the assembly equipment, as applicable.
This type of fitting is part of an electrical system as specified by IEC 60335-1,[4] IEC 60364-1[5] and
IEC 60449.[6] Protection against direct contact with active parts (live conductors) shall be required in
accordance with IEC 60529. This protection is a function of the work site conditions.
NOTE See Annex A for examples of typical electrofusion terminal connectors.
The surface finish of the terminal pins shall allow a minimum contact resistance in order to satisfy the
resistance tolerance requirements (nominal value ±10 %).
5.5 Appearance of factory-made fusion joints
The following requirements apply only to joints and fittings made or assembled in the factory.
The internal and external surfaces of the pipe and fitting after fusion jointing, examined visually without
magnification, shall be free from melt exudation outside the confines of the fittin
...