ISO 4437-4:2015
(Main)Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 4: Valves
Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 4: Valves
ISO 4437-4:2015 specifies the characteristics of valves made from polyethylene (PE) for 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 part of ISO 4437.
Systèmes de canalisations en plastique pour la distribution des combustibles gazeux — Polyéthylène (PE) — Partie 4: Robinets
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 4437-4
First edition
2015-04-15
Plastics piping systems for the supply
of gaseous fuels — Polyethylene (PE) —
Part 4:
Valves
Systèmes de canalisations en plastique pour la distribution des
combustibles gazeux — Polyéthylène (PE) —
Partie 4: Robinets
Reference number
ISO 4437-4:2015(E)
©
ISO 2015
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ISO 4437-4:2015(E)
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ii © ISO 2015 – All rights reserved
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ISO 4437-4:2015(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols, and abbreviations . 2
3.1 General terms . 2
3.2 Terms relating to design . 3
4 Material . 3
4.1 PE compound . 3
4.2 Material for non-polyethylene parts . 4
4.2.1 General. 4
4.2.2 Metal parts . 4
4.2.3 Elastomers . 4
4.2.4 Other materials . 4
5 General characteristics . 4
5.1 Appearance of the valve . 4
5.2 Colour . 5
5.3 Design . 5
5.3.1 General. 5
5.3.2 Valve body . 5
5.3.3 Operating device . 5
5.3.4 Seals . 5
6 Geometrical characteristics . 5
6.1 General . 5
6.2 Measurement of dimensions . 6
6.3 Dimensions of spigot ends for valves . 6
6.4 Dimensions of valves with electrofusion sockets . 6
6.5 Dimensions of the operating device . 6
7 Mechanical characteristics of assembled valves . 6
7.1 General . 6
7.2 Requirements . 6
8 Physical characteristics .10
8.1 Conditioning .10
8.2 Requirements .10
9 Performance requirements .11
10 Marking .11
10.1 General .11
10.2 Minimum required marking .11
10.3 Additional marking .12
11 Delivery conditions .12
Annex A (normative) Determination of the leaktightness of seat and packing .13
Annex B (normative) Test method for leaktightness and ease of operation after tensile loading .14
Bibliography .16
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ISO 4437-4:2015(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT), see the following URL: Foreword — Supplementary information.
The committee responsible for this document is ISO/TC 138, Plastics pipes, fittings and valves for the
transport of fluids, Subcommittee SC 7, Valves and auxiliary equipment of plastics materials.
This first edition cancels and replaces ISO 10933:1997.
ISO 4437 consists of the following parts, under the general title Plastics piping systems for the supply of
gaseous fuels — Polyethylene (PE):
— Part 1: General
— Part 2: Pipes
— Part 3: Fittings
— Part 4: Valves
— Part 5: Fitness for purpose of the system
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ISO 4437-4:2015(E)
Introduction
Characteristics for fitness for purpose are covered in ISO 4437-5. ISO/TS 10839 gives recommended
practices for installation.
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INTERNATIONAL STANDARD ISO 4437-4:2015(E)
Plastics piping systems for the supply of gaseous fuels —
Polyethylene (PE) —
Part 4:
Valves
1 Scope
This part of ISO 4437 specifies the characteristics of valves made from polyethylene (PE) for 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 part of ISO 4437.
In conjunction with ISO 4437-1, ISO 4437-2, ISO 4437-3:2014, and ISO 4437-5, it is applicable to PE valves,
their joints, and to joints with components of PE and other materials intended to be used under the
following conditions:
a) the maximum operating pressure, MOP, is based on the design stress determined from the compound
MRS divided by the C factor and taking into account RCP requirements;
b) temperature of 20 °C as reference temperature;
NOTE 1 For other operating temperatures, derating coefficients are given in ISO 4437-5:2014.
c) operating temperature between −20 °C and +40 °C.
This International Standard covers a range of maximum operating pressures and gives requirements
concerning colours and additives.
NOTE 2 It is the responsibility of the purchaser or specifier to make the appropriate selections from these
aspects, taking into account their particular requirements and any relevant national regulations and installation
practices or codes.
It is applicable to bi-directional valves with spigot ends or electrofusion sockets intended to be
jointed with PE pipes conforming to ISO 4437-2 without any fittings or with PE fittings conforming to
ISO 4437-3:2014.
This part of ISO 4437 covers valves for pipes with a nominal outside diameter d ≤ 400 mm.
n
NOTE 3 Valves made from materials other than polyethylene designed for the supply of gaseous fuels conforming
to the relevant standards are permitted to be used in PE piping systems according to ISO 4437 provided that
they have relevant PE connections for butt fusion or electrofusion ends (see ISO 4437-3). The component, i.e. the
complete valve, shall fulfil the requirements of this part of ISO 4437.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. 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
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ISO 4437-4:2015(E)
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 3127, Thermoplastics pipes — Determination of resistance to external blows — Round-the-clock method
ISO 4437-1, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 1: General
ISO 4437-2, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 2: Pipes
ISO 4437-3:2014, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 3: Fittings
ISO 4437-5, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 5: Fitness for
purpose of the system
ISO 8233, Thermoplastics valves — Torque — Test method
ISO 11357-6, Plastics — Differential scanning calorimetry (DSC) — Part 6: Determination of oxidation
induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)
ISO 12176-4, Plastics pipes and fittings — Equipment for fusion jointing polyethylene systems — Part 4:
Traceability coding
ISO 16010, Elastomeric seals — Material requirements for seals used in pipes and fittings carrying gaseous
fuels and hydrocarbon fluids
ISO 17778, Plastics piping systems ― Fittings, valves and ancillaries ― Determination of gaseous flow
rate/pressure drop relationships
EN 736-1, Valves ― Terminology ― Part 1: Definition of types of valves
EN 736-2, Valves ― Terminology ― Part 2: Definition of components of valves
EN 1680, Plastics piping systems ― Valves for polyethylene (PE) piping systems ― Test method for
leaktightness under and after bending applied to the operating mechanisms
EN 1704, Plastics piping systems ― Thermoplastics valves ― Test method for the integrity of a valve after
temperature cycling under bending
EN 1705, Plastics piping systems ― Thermoplastics valves ― Test method for the integrity of a valve after
an external blow
EN 12100, Plastics piping systems ― Polyethylene (PE) valves ― Test method for resistance to bending
between supports
EN 12119, Plastics piping systems ― Polyethylene (PE) valves ― Test method for resistance to thermal cycling
3 Terms, definitions, symbols, and abbreviations
For the purposes of this document, the terms, definitions, symbols, and abbreviations given in ISO 4437-1,
EN 736-1, EN 736-2, and the following apply.
3.1 General terms
3.1.1
external leaktightness
leaktightness of the valve body enveloping the space containing the gas with respect to the atmosphere
3.1.2
internal leaktightness
leaktightness between the inlet and the outlet of the valve with the valve in the closed position
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ISO 4437-4:2015(E)
3.1.3
leaktightness test
test for both of the following characteristics:
a) internal leaktightness of a valve’s closing seat when closed and pressurized from either side;
b) external leaktightness of a valve when half open
3.1.4
initiating torque
torque required to initiate movement of the obturator
3.1.5
running torque
torque required to achieve full opening or closing of the valve at maximum allowable operating pressure
3.1.6
leakage
emission of gas from a valve body or any component of a valve
3.1.7
valve body
main part of a valve which contains the obturating device (closing element, seat, packing seals, and
operating stop) as applicable and provides the terminal ends for connection to the PE pipe/fittings
3.1.8
operating device
part of a valve for connection with the operating key which allows the opening and the closing of the valve
3.2 Terms relating to design
3.2.1
full bore valve
valve with a flow section equal to or greater than 80 % of the section corresponding to the nominal
inside diameter of the body end port
[SOURCE: EN 736-3:2008]
3.2.2
clearway valve
valve designed to have an unobstructed flow way which allows for the passage of a theoretical sphere
with a diameter that is not less than the nominal inside diameter of the body end port
[SOURCE: EN 736-3:2008]
3.2.3
reduced bore valve
valve with a flow section equal to or greater than 36 % of the section corresponding to the nominal
inside diameter of the body end port and which does not correspond to the full bore valve
[SOURCE: EN 736-3:2008]
4 Material
4.1 PE compound
The PE compound from which the valve body with spigot ends or electrofusion sockets is made shall conform
to ISO 4437-1. The stress bearing parts shall only be made from virgin material conforming to ISO 4437-1.
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ISO 4437-4:2015(E)
4.2 Material for non-polyethylene parts
4.2.1 General
All components shall conform to the relevant International Standards. Alternative standards may be
applied in cases where suitable International Standards do not exist.
In all cases, fitness for purpose of the components shall be demonstrated.
The materials and the constituent elements used in making the valve (including elastomers, greases,
and any metal parts, as may be used) shall be resistant to the external and internal environments as
the other elements of the piping system and shall have a life expectancy under the following conditions
at least equal to that of the PE pipes conforming to ISO 4437-2 with which they are intended to be used:
a) during storage;
b) under the effect of the gas conveyed therein;
c) with respect to the service environment and operating conditions.
The requirements for the level of material performance of non-polyethylene parts shall be at least as
stringent as that of the PE compound for the piping system. Rework materials shall not be used for stress
bearing polymeric parts.
Other materials used in valves in contact with the PE pipe shall not adversely affect pipe performance
or initiate stress cracking.
Metal valve bodies for PE piping systems up to 10 bar should conform to the relevant standard of ISO 153.
4.2.2 Metal parts
All metal parts susceptible to corrosion shall be adequately protected, provided that this is necessary
for the durability and function of the system.
When dissimilar metallic materials are used which might be in contact with moisture, steps shall be
taken to avoid the possibility of galvanic corrosion.
4.2.3 Elastomers
Elastomeric seals shall conform to ISO 16010.
Other sealing materials are permitted if proven suitable for gas service.
4.2.4 Other materials
Greases or lubricants shall not exude onto fusion areas and shall not affect the long-term performance
of the valve materials.
Other materials conforming to 4.2.1 may be used provided that it is proven that the valves conform to
this part of ISO 4437.
5 General characteristics
5.1 Appearance of the valve
When viewed without magnification, the internal and external surfaces of valves shall be smooth and
clean and shall have no scoring, cavities, and other surface defects to an extent that would prevent
conformity to this part of ISO 4437.
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ISO 4437-4:2015(E)
No component of the valve shall show any signs of damage, scratches, pitting, bubbles, blisters, inclusions, or
cracks to an extent that would prevent conformity of the valves to the requirements of this part of ISO 4437.
5.2 Colour
The colour of the PE parts of valves shall either be black, yellow, or orange.
5.3 Design
5.3.1 General
The design of the valve shall be such that, when assembling the valve onto the pipe or other components,
the electrical coils and/or seals or any other ancillary parts are not displaced.
PE valves bodies and their PE spigot ends or electrofusion sockets shall have a pressure rating of at least
that of the pipe to which they are jointed.
5.3.2 Valve body
The valve body shall be such that it cannot be dismantled.
5.3.3 Operating device
The operating device shall be integral with or connected to the stem in such a way that disconnection is
not possible during normal operation.
The valve shall close by turning the operating device clockwise. For a quarter-turn valve, the position of
the obturator shall be clearly indicated on the top side of the operating device.
Stops shall be provided at the fully open and closed positions.
5.3.4 Seals
The seals, conforming to 4.2.3, shall be so mounted as to be resistant to normally occurring mechanical
loads. Creep and cold flow effects shall be taken into account. Any mechanism that puts a loading on the
seals shall be permanently locked. Line pressure shall not be used as the sole means of seal activation.
5.4 Appearance of factory made joints
The internal and external surfaces of the pipe and valve parts after fusion jointing, examined visually
without magnification, shall be free from melt exudation outside the confines of the valve, apart from
that which can be declared acceptable by the valve manufacturer or used deliberately as a fusion marker.
6 Geometrical characteristics
6.1 General
Each valve shall be characterized by its dimensions and associated end connections.
Technical data given by the manufacturer shall include at least the following information:
a) dimensional characteristics, by working drawings;
b) assembly instructions.
In order to prevent stress concentrations, any changes in the wall thickness of the valve body should be
gradual.
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ISO 4437-4:2015(E)
6.2 Measurement of dimensions
Dimensions shall be measured in accordance with ISO 3126 at (23 ± 2) °C, after being conditioned for at
least 4 h. The measurement shall not be made less than 24 h after manufacture.
NOTE Indirect measurement at the stage of production is allowed at shorter time periods provided that
evidence is shown of correlation.
6.3 Dimensions of spigot ends for valves
The dimensions of spigot ends shall conform to ISO 4437-3:2014, Table 3 up to and including d 400 mm.
n
6.4 Dimensions of valves with electrofusion sockets
The dimensions of electrofusion sockets shall conform to ISO 4437-3:2014, Table 1 up to and
including d 400 mm.
n
6.5 Dimensions of the operating device
For a quarter-turn valve, the dimension of the operating devices shall be designed so it can be operated
+05,
with a (50 ) mm square socket, (40 ± 2) mm depth.
0
NOTE For a non-quarter-turn operated valve, attention is drawn to the requirements specified in ISO 5210.
7 Mechanical characteristics of assembled valves
7.1 General
All tests shall be carried out on valves assembled with pipe from the same series conforming to
ISO 4437-2, in accordance with the technical instructions and the extreme installation conditions of
utilization described in ISO 4437-5.
NOTE The properties of an assembled valve depend on the properties of the pipes and the valve and on
the conditions of their installation (i.e. geometry, temperature, type, method of conditioning, assembly, and
fusion procedures).
The technical descriptions of the manufacturer shall include at least the following information:
a) service conditions (e.g. valve temperature limits);
b) assembly instructions;
c) for valves with electrofusion sockets, the fusion instructions (power requirements or fusion
parameters with limits).
7.2 Requirements
Unless otherwise specified by the applicable test method, the test pieces shall be conditioned at
(23 ± 2) °C before testing in accordance with Table 1.
When tested in accordance with the test methods as specified in Table 1 using the indicated parameters,
the valves shall have mechanical characteristics conforming to the requirements given in Table 1.
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ISO 4437-4:2015(E)
Table 1 — Mechanical characteristics
Test parameters
Characteristic Requirements Test method
Parameter Value
a
Hydrostatic
No failure during the Conditioning time Shall conform to ISO 1167-1 ISO 1167-1 and
b
strength test period of any Number of test pieces 3 ISO 1167-4
f
(20 °C, 100 h) test piece Type of test Water-in-water
Circumferential (hoop)
stress: PE 80 10,0 MPa
PE 100 12,0 MPa
Test period 100 h
Test temperature 20 °C
a
Hydrostatic No failure during the Conditioning time Shall conform to ISO 1167-1 ISO 1167-1 and
b
strength test period of any Number of test pieces 3 ISO 1167-4
c f
(80 °C, 165 h) test piece Type of test Water-in-water
Circumferential (hoop)
stress: PE 80 4,5 MPa
PE 100 5,4 MPa
Test period 165 h
Test temperature 80 °C
a
Hydrostatic No failure during the Conditioning time Shall conform to ISO 1167-1 ISO 1167-1 and
b
strength test period of any Number of test pieces 3 ISO 1167-4
f
(80 °C, 1 000 h) test piece Type of test Water-in-water
Circumferential (hoop)
stress: PE 80 4,0 MPa
PE 100 5,0 MPa
Test period 1 000 h
Test temperature 80 °C
Leaktightness of No leakage during Test temperature 23 °C Annex A
seat and packing the test period Type fluid Air or nitrogen
b
Number of test pieces 1
Test pressure 25 mbar
Duration of the test 1 h
Leaktightness of No leakage during Test temperature 23 °C Annex A
seat and packing the test period Type fluid Air or nitrogen
b
Number of test pieces 1
Test pressure 1,5 MOP
Duration of the test 30 s
SAFETY PRECAUTIONS — Safety precautions need to be taken when testing with air or nitrogen up to 1,5 MOP.
For testing with air or nitrogen, a pressure of a maximum of 6 bar should be used. For MOP >4 bar, testing
with water should be considered and the test conditions shall be agreed upon between the manufacturer and
end user.
Pressure drop Air flow rate Type of test Air ISO 17778
b
(value indicated by Number of test pieces 1
the manufacturer) Test pressure 25 mbar
Pressure drop for
d ≤ 63 mm 0,5 mbar
n
d > 63 mm 0,1 mbar
n
Operating Torque range: Test temperatures −20 °C and ISO 8233
d
torque — For d ≤ 63 mm +23 °C and
n
5 Nm < M ≤ 35 Nm +40 °C
b
— For Number of test pieces 1
63 mm < d ≤ 125 mm
n
10 Nm < M ≤ 70 Nm
— For
125 mm < d ≤ 400 mm
n
g
M > 10 Nm
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ISO 4437-4:2015(E)
Table 1 (continued)
Test parameters
Characteristic Requirements Test method
Parameter Value
Stop resistance a) No failure at stops, Test temperature −20 °C and +40 °C a) ISO 8233
b
Number of test pieces 1
and followed by
Torque 2 times the value of the
maximum measured oper-
b) No leakage at seat b) Annex A
ating torque with minimum
and packing
150 Nm, during 15 s
Actuation
...
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