ISO 16486-4:2016

INTERNATIONAL ISO
STANDARD 16486-4
First edition
2016-06-01
Plastics piping systems for the supply
of gaseous fuels — Unplasticized
polyamide (PA-U) piping systems
with fusion jointing and mechanical
jointing —
Part 4:
Valves
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 4: Robinets
Reference number
ISO 16486-4:2016(E)
©
ISO 2016

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ISO 16486-4:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
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ISO 16486-4:2016(E)

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 . 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 . 4
5.3 Design . 4
5.3.1 General. 4
5.3.2 Valve body . 4
5.3.3 Operating device . 5
5.3.4 Seals . 5
5.4 Fusion compatibility . 5
6 Geometrical characteristics . 5
6.1 General . 5
6.2 Measurement of dimensions . 5
6.3 Dimensions of spigot ends for valves . 5
6.4 Dimensions of valves with electrofusion sockets . 5
6.5 Dimensions of the operating device . 6
7 Mechanical characteristics of assembled valves . 6
7.1 General . 6
7.2 Conditioning . 6
7.3 Requirements . 6
8 Physical characteristics .11
8.1 Conditioning .11
8.2 Requirement .11
9 Performance requirements .11
10 Marking .12
10.1 General .12
10.2 Minimum required marking of valves .12
10.3 Additional information required on valve or label .12
10.4 Fusion system recognition .12
11 Packaging .13
Annex A (normative) Determination of the leaktightness of seat and packing .14
Annex B (normative) Test method for leaktightness and ease of operation after tensile loading .15
Bibliography .17
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ISO 16486-4:2016(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.
ISO 16486 consists of the following parts, under the general title Plastics piping systems for the supply
of gaseous fuels — Unplasticized polyamide (PA-U) piping systems with fusion jointing and mechanical
jointing:
— Part 1: General
— Part 2: Pipes
— Part 3: Fittings
— Part 4: Valves
— Part 5: Fitness for purpose of the system
— Part 6: Code of practice for design, handling and installation
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ISO 16486-4:2016(E)

Introduction
Thin wall thickness unplasticized polyamide (PA-U) pipes and solvent cement joints are used typically
for low pressures, while thicker wall thickness pipes and butt fusion, electrofusion, or mechanical joints
are typically used for high pressures.
For technical and safety reasons, it is not possible to mix the components of the two types of piping
system (thin wall thickness pipes cannot be jointed by butt fusion or mechanical joints and vice versa).
In particular, solvent cement joints shall not be used for jointing for high pressure piping systems.
So for the time being, the standardization programme dealing with unplasticized polyamide (PA-U)
piping systems for the supply of gaseous fuels is split into two series of International Standards, with
one series (ISO 17467) covering piping systems the components of which are connected by solvent
cement jointing and the other (ISO 16486), the components of which are connected by fusion jointing
and/or mechanical jointing. When more experience will be gained from the field, it might be reasonable
to merge ISO 17467 series and ISO 16486 series in one single series applicable to PA-U piping systems.
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INTERNATIONAL STANDARD ISO 16486-4:2016(E)
Plastics piping systems for the supply of gaseous fuels —
Unplasticized polyamide (PA-U) piping systems with fusion
jointing and mechanical jointing —
Part 4:
Valves
1 Scope
This part of ISO 16486 specifies the characteristics of valves made from unplasticized polyamide (PA-
U) in accordance with ISO 16486-1, intended to be buried and used for the supply of gaseous fuels.
Valves made from other material than unplasticized polyamide designed for the supply of gaseous
fuels conforming to the relevant standards are permitted to be used in PA-U piping system according
to ISO 16486 provided they have relevant PA-U connections for butt fusion or electrofusion ends
(see ISO 16486-3). The component, i.e. the complete valve, shall fulfil the requirements of this part of
ISO 16486.
It also specifies the test parameters for the test methods referred to in this part of ISO 16486.
It is applicable to bi-directional valves with spigot end or electrofusion socket intended to be jointed
with PA-U pipes conforming to ISO 16486-2 without any fittings or with PA-U fittings conforming to
ISO 16486-3.
This part of ISO 16486 covers valves for pipes with a nominal outside diameter, d , ≤250 mm.
n
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 291, Plastics — Standard atmospheres for conditioning and testing
ISO 307, Plastics — Polyamides — Determination of viscosity number
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 3127, Thermoplastics pipes — Determination of resistance to external blows — Round-the-clock method
ISO 8233, Thermoplastics valves — Torque — Test method
ISO 9393-1:2004, Thermoplastics valves for industrial applications — Pressure test methods and
requirements — Part 1: General
ISO 16010, Elastomeric seals — Material requirements for seals used in pipes and fittings carrying gaseous
fuels and hydrocarbon fluids
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ISO 16486-4:2016(E)

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 16486-3:2012, 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 16486-5, 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
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 and definitions
For the purposes of this document, the terms and definitions given in ISO 16486-1, EN 736-1, EN 736-2
and the following apply.
3.1
external leaktightness
leaktightness (3.3) of the valve body (3.6) enveloping the space containing the gas, with respect to the
atmosphere
3.2
internal leaktightness
leaktightness (3.3) between the inlet and the outlet of the valve, with the valve in the closed position
3.3
leaktightness test
test for both of the following characteristics:
a) the internal leaktightness (3.2) of a valve’s closing seat when closed and pressurized from either side;
b) the external leaktightness (3.1) of a valve when half open
3.4
initiating torque
torque required to initiate movement of the obturator
3.5
running torque
torque required to achieve full opening or closing of the valve at maximum allowable operating pressure
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ISO 16486-4:2016(E)

3.6
leakage
emission of gas from a valve body (3.6) or any component of a valve
3.7
valve body
main part of a valve which contains the obturating device (closing element, the seat, the packing
seals and the operating stop), as applicable and provides the terminal ends for connection to the PA-U
pipe/fittings
3.8
operating device
part of a valve for connection with the operating key which allows the opening and the closing of the valve
3.9 Terms relating to design
3.9.1
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]
3.9.2
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]
3.9.3
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 (3.9.1)
4 Material
4.1 PA-U compound
The valves shall be made from virgin material.
The compound from which the valves 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 valve shall be resistant to the external and
internal environments in which they are intended to be used
a) during storage,
b) under the effect of the fluids being conveyed, and
c) taking account of the service environment and operating conditions.
Valves materials, including elastomers, greases, and lubricants in contact with the PA-U pipe, shall not
adversely affect pipe performance or initiate stress cracking.
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ISO 16486-4:2016(E)

Metal valve bodies for PA-U piping systems up to 20 bar should conform to the relevant standard of
ISO/TC 153”Valves”.
4.2.2 Metal parts
All parts susceptible to corrosion shall be adequately protected, providing this is necessary for the
durability and function of the system.
When dissimilar metallic materials are used which may be in contact with moisture, steps shall be
taken to avoid the possibility of galvanic corrosion.
4.2.3 Elastomers
Elastomeric materials used for the manufacture of seals shall be in accordance with ISO 16010.
Other sealing materials are permitted if proven suitable for gas service.
4.2.4 Other materials
Greases and lubricants shall not exude on to the fusion areas and shall not affect the long-term
performance of the pipe/valve.
Other materials conforming to 4.2.1 may be used provided that it is proven that the valves conform to
this part of ISO 16486.
5 General characteristics
5.1 Appearance of the valve
When viewed without magnification, the internal and external surfaces of valves shall be smooth, clean,
and free from scoring, cavities, or other surface defects to an extent that would prevent conformity to
this part of ISO 16486.
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 this part of ISO 16486.
5.2 Colour
The colour of the PA-U parts of valves shall be either black or yellow.
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, if any, and/or seals or any other ancillary parts are not displaced.
PA-U valves bodies and their PA-U 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.
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ISO 16486-4:2016(E)

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, which elastomeric materials are 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 Fusion compatibility
Components made from PA-U 11 shall be heat fusion jointed only to components made from PA-U 11.
Components made from PA-U 12 shall be heat fusion jointed only to components made from PA-U 12.
Components made from PA-U are not fusion compatible with components made from other polymers.
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) the dimensional characteristics, by working drawings;
b) the assembly instructions.
In order to prevent stress concentrations, any changes in the wall thickness of the valve body should be
gradual.
6.2 Measurement of dimensions
The dimensions of the fittings shall be measured in accordance with ISO 3126. In case of dispute, the
measurement of dimensions shall be made not less than 24 h after manufacture and after conditioning
for at least 4 h at (23 ± 2) °C.
6.3 Dimensions of spigot ends for valves
The dimensions of spigot ends shall conform to ISO 16486-3:2012, Table 4, up to and including d 250 mm.
n
6.4 Dimensions of valves with electrofusion sockets
The dimensions of electrofusion sockets shall conform to ISO 16486-3:2012, Table 1, up to and including
d 250 mm.
n
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ISO 16486-4:2016(E)

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, the attention is drawn on 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 16486-2, in accordance with the technical instructions and the extreme installation conditions of
utilization described in ISO 16486-5.
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 Conditioning
Unless otherwise specified in the applicable test method, the test pieces shall be conditioned for at least
16 h at 23 °C and 50 % relative humidity in accordance with ISO 291 before testing in accordance with
Table 1.
7.3 Requirements
The test pieces shall be tested in accordance with Table 1. When tested using the test method and
parameters specified therein, the valves shall have mechanical characteristics conforming to the
requirements of Table 1.
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ISO 16486-4:2016(E)

Table 1 — Mechanical characteristics of valves
Test parameters
Characteristic Requirements Test method
Parameter Value
a
Hydrostatic No failure during the Conditioning period 6 h ISO 1167-1
strength  test period of any
Type of test Water-in-water
ISO 1167-4
(20 °C, 1 000 h) test piece
Test temperature 20 °C
Test period 100 h
Circumferential (hoop) 19,0 MPa
stress 20,0 MPa
b
PA-U 11 and PA-U 12 160
b
PA-U 11 and PA-U 12 180
a
Hydrostatic No failure during the Conditioning period 6 h ISO 1167-1
strength test period of any
Type of test Water-in-water
ISO 1167-4
(80 °C, 165 h) test piece
Test temperature 80 °C
Test period 165 h
Circumferential (hoop) 10,0 MPa
stress 11,5 MPa
b
PA-U 11 and PA-U 12 160
b
PA-U 11 and PA-U 12 180
Leaktightness of No leakage during Test temperature 23 °C Annex A
seat and packing the test period Type fluid Air or nitrogen
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
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 between the
manufacturer and end user.
Pressure drop Air flow rate Type of test Air ISO 17778
(value indicated by Test pressure 25 mbar
the manufacturer) Pressure drop for
  d ≤ 63 mm 0,5 mbar
n
  d > 63 mm 0,1 mbar
n
a
The valves shall not be pressurized within 24 h after fusion.
b
For material classification and designation, see ISO 16486-1:2012, 5.4.
c
The initiating torque and the running torque shall be within the torque range given in this table.
d
After at least 24 h after the completion of the internal pressure test, the other four tests shall be carried out on the
valve in the order stated.
e
Alternatively, for d > 200 mm, the test can also be performed in air. In case of dispute, water in water shall be used.
n
f
The maximum torque manually applied to the gear or lever shall not exceed 250 Nm and the maximum diameter of the
wheel or the length of the lever shall be less than 1 m.
g
The numbers of test pieces given indicate the numbers required to establish a value for the characteristic described in
the table. The numbers of test pieces required for the factory production control and process control should be listed in the
manufacturer’s quality plan.
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ISO 16486-4:2016(E)

Table 1 (continued)
Test parameters
Characteristic Requiremen
...