ISO 22391-3:2007

INTERNATIONAL ISO
STANDARD 22391-3
First edition
2007-01-15

Plastics piping systems for hot and cold
water installations — Polyethylene of
raised temperature resistance (PE-RT) —
Part 3:
Fittings
Systèmes de canalisations en plastique pour les installations d'eau
chaude et froide — Polyéthylène de meilleure résistance à la
température (PE-RT) —
Partie 3: Raccords




Reference number
ISO 22391-3:2007(E)
©
ISO 2007

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ISO 22391-3:2007(E)
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ii © ISO 2007 – All rights reserved

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ISO 22391-3:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms. 2
3.2 Mechanical fittings. 3
3.3 Fittings for heat fusion. 3
4 Material characteristics. 3
4.1 Plastics fitting material. 3
4.2 Metallic fitting material. 5
4.3 Influence on water intended for human consumption. 5
5 General characteristics . 5
5.1 Appearance . 5
5.2 Opacity. 5
6 Geometrical characteristics. 5
6.1 General. 5
6.2 Dimensions of sockets for socket fusion and electrofusion fittings . 6
6.3 Dimensions of metallic fittings. 10
7 Mechanical characteristics of plastics fittings . 10
7.1 General. 10
7.2 Fitting material identical to PE-RT compound. 10
7.3 Fitting made from PE-RT but not identical to PE-RT compound. 10
7.4 Fittings made from plastics other than PE-RT . 10
8 Physical and chemical characteristics of plastics components . 11
8.1 Melt mass flow rate. 11
9 Sealing elements. 11
10 System performance requirements . 11
11 Marking . 12
11.1 General requirements. 12
11.2 Minimum required marking. 12

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ISO 22391-3:2007(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22391-3 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 2, Plastics pipes and fittings for water supplies.
ISO 22391 consists of the following parts, under the general title Plastics piping systems for hot and cold
water installations — Polyethylene of raised temperature resistance (PE-RT):
⎯ Part 1: General
⎯ Part 2: Pipes
⎯ Part 3: Fittings
⎯ Part 5: Fitness for purpose of the system
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ISO 22391-3:2007(E)
Introduction
ISO 22391, the system standard, specifies the requirements for a piping system and its components when
made from polyethylene of raised temperature resistance (PE-RT). The piping system is intended to be used
for hot and cold water installations.
In respect of potential adverse effects on the quality of water intended for human consumption caused by the
products covered by ISO 22391:
a) no information is provided as to whether the products may be used without restriction;
b) existing national regulations concerning the use and/or characteristics of the products remain in force.
This part of ISO 22391 specifies the characteristics of fittings. At the time of its publication, system standards
for piping systems of other plastics materials used for the same application are
⎯ ISO 15874:2003, Plastics piping systems for hot and cold water installations — Polypropylene (PP),
⎯ ISO 15875:2003, Plastics piping systems for hot and cold water installations — Crosslinked polyethylene
(PE-X),
⎯ ISO 15876:2003, Plastics piping systems for hot and cold water installations — Polybutylene (PB), and
⎯ ISO 15877:2003, Plastics piping systems for hot and cold water installations — Chlorinated
poly(vinyl chloride) (PVC-C).

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INTERNATIONAL STANDARD ISO 22391-3:2007(E)

Plastics piping systems for hot and cold water installations —
Polyethylene of raised temperature resistance (PE-RT) —
Part 3:
Fittings
1 Scope
This part of ISO 22391 specifies the characteristics of fittings for piping systems made from polyethylene of
raised temperature resistance (PE-RT), intended to be used for hot and cold water installations within
buildings for the conveyance of water — whether or not the water is intended for human consumption
(domestic systems) or heating systems — under the design pressures and temperatures appropriate to the
class of application according to ISO 22391-1.
It covers a range of service conditions (classes of application), design pressures and pipe dimension classes,
and also specifies test parameters and test methods. When used in conjunction with the other parts of
ISO 22391, it is applicable to fittings made from PE-RT, as well as to those made from other materials,
intended to be fitted to pipes conforming to ISO 22391-2 for hot and cold water installations, the joints of which
are in accordance with ISO 22391-5.
This part of ISO 22391 is applicable to the following types of fitting:
⎯ mechanical fittings;
⎯ socket fusion fitting;
⎯ electrofusion fittings;
⎯ fittings with incorporated inserts.
It is not applicable for values of design temperature, maximum design temperature or malfunction temperature
in excess of those specified in ISO 22391-1.
NOTE 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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 7-1, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances
and designation
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,
tolerances and designation
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ISO 22391-3:2007(E)
ISO 1133:2005, Plastics — Determination of the melt mass-flow rate (MFR) and the melt volume-flow rate
(MVR) of thermoplastics
ISO 1167-1:2006, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination
of the resistance to internal pressure — Part 1: General method
ISO 1167-2:2006, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination
of the resistance to internal pressure — Part 2: Preparation of pipe test pieces
ISO 3126:2005, Plastics piping systems — Plastics components — Determination of dimensions
ISO 7686:2005, Plastics pipes and fittings — Determination of opacity
ISO 9080, Plastics piping and ducting systems — Determination of long-term hydrostatic strength of
thermoplastic materials in pipe form by extrapolation
ISO 12092, Fittings, valves and other piping system components made of unplasticized poly(vinyl chloride)
(PVC-U), chlorinated poly(vinyl chloride) (PVC-C), acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-
styrene-acrylester (ASA) for pipes under pressure — Resistance to internal pressure — Test method
ISO 23711, Elastomeric seals — Requirements for materials for pipe joint seals used in water and drainage
applications — Thermoplastic elastomers
ISO 22391-1, Plastics piping systems for hot and cold water installations — Polyethylene of raised
temperature resistance (PE-RT) — Part 1: General
ISO 22391-2:2006, Plastics piping systems for hot and cold water installations — Polyethylene of raised
temperature resistance (PE-RT) — Part 2: Pipes
ISO 22391-5, Plastics piping systems for hot and cold water installations — Polyethylene of raised
temperature resistance (PE-RT) — Part 5: Fitness for purpose of the system
EN 681-1, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 1: Vulcanized rubber
EN 681-2, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 2: Thermoplastic elastomers
EN 1254-3:1998, Copper and copper alloys — Plumbing fittings — Part 3: Fittings with compression ends for
use with plastics pipes
EN 10088-1:1995, Stainless steels — Part 1: List of stainless steels
EN 12107, Plastics piping systems — Injection-moulded thermoplastics fittings, valves and ancillary
equipment — Determination of the long-term hydrostatic strength of thermoplastics materials for injection
moulding of piping components
3 Terms, definitions, symbols and abbreviated terms
For the purposes of this document, the terms, definitions, symbols and abbreviated terms given in
ISO 22391-1 and the following apply.
3.1
fitting
component of a piping system which connects two or more pipes and/or fittings together, without any further
function
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ISO 22391-3:2007(E)
3.2 Mechanical fittings
3.2.1
compression fitting
fitting in which the joint is made by the compression of a ring or sleeve on the outside wall of the pipe with or
without additional sealing elements and with internal support
3.2.2
crimped fitting
fitting in which the joint is made by crimping of the fitting and/or a ring on the outside wall of the pipe by means
of a special tool
3.2.3
flanged fitting
fitting in which the pipe connection consists of two mating flanges which are mechanically pressed together
and sealed by the compression of an elastomeric sealing element between them
3.2.4
flat seat union fitting
fitting in which the pipe connection consists primarily of two components, at least one of which normally
incorporates a flat sealing surface, which are mechanically pressed together by means of a screwed nut or
similar and sealed by the compression of an elastomeric sealing element between them
3.3 Fittings for heat fusion
3.3.1
socket fusion fitting
fitting in which the joint with the pipe is made by melting together the outer part of the pipe with the inner part
of the fitting by means of heat induced by a heated tool
3.3.2
electrofusion fitting
fitting in which the joint with the pipe is made by melting together the outer part of the pipe and the inner part
of the fitting by means of heat induced by current flowing in an appropriate resistor inserted in the fitting body
3.4
fitting with incorporated inserts
fitting in which the joint is made by means of connecting threads or other outlets, inserted in the plastics body,
combined with fusion ends for socket welding or electrofusion
4 Material characteristics
4.1 Plastics fitting material
4.1.1 Fitting material identical to PE-RT pipe material
The material from which fittings are made shall be in accordance with the requirements for pipes according to
ISO 22391-2.
When tested using the test method and the test parameters in accordance with Table 1, injection moulded
tubular test pieces shall withstand the hydrostatic (hoop) stress without bursting or leakage.

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ISO 22391-3:2007(E)
Table 1 — Mechanical characteristics of tubular test pieces made of PE-RT by injection moulding
Test parameters
Characteristic Requirement Test methods
For individual tests
Hydrostatic Test
Test period
Number of
(hoop) stress temperature
test pieces
MPa °C h
9,9 20 1 3
ISO 1167-1
3,4 95 1 000 3
No bursting or and
Resistance to
leakage during ISO 1167-2
internal pressure
For all tests
test period (together with
EN 12107)
Sampling procedure Not specified
Type of end cap Type a)
Orientation of test piece Not specified
Type of test
...