ISO 16486-6:2012

INTERNATIONAL ISO
STANDARD 16486-6
First edition
2012-06-01
Plastics piping systems for the supply of
gaseous fuels — Unplasticized polyamide
(PA-U) piping systems with fusion
jointing and mechanical jointing —
Part 6:
Code of practice for design, handling
and installation
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 6: Code de pratique pour la conception, la manutention
Reference number
©
ISO 2012
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Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 2
5 Design . 3
5.1 General . 3
5.2 Materials, components and jointing equipment. 3
5.3 Maximum operating pressure . 3
5.4 Assembly techniques . 4
5.5 Squeeze-off properties . 4
6 Installation . 4
6.1 Jointing procedure . 4
6.2 Training . 5
6.3 Heated-tool fusion jointing . 5
6.4 Electrofusion jointing . 9
6.5 Laying .12
7 Storage, handling and transport .14
7.1 General .14
7.2 Storage .14
7.3 Handling .15
7.4 Transport .16
8 Quality control .16
8.1 General .16
8.2 Inspection prior to laying .16
8.3 Inspection during laying .17
Annex A (normative) Derating coefficients for operating temperatures .19
Bibliography .20
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 16486-6 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 first edition of ISO 16486-6 cancels and replaces the first edition of ISO 22621-6:2010 which has been
technically revised.
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 5: Fitness for purpose of the system
— Part 6: Code of practice for design, handling and installation
iv © ISO 2012 – All rights reserved

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 must 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 the ISO 17467 series and
the ISO 16486 series in one single series applicable to PA-U piping systems.
A similar series (ISO 17135) for fusion and mechanically jointed plasticized polyamide (PA-P) piping systems
is in preparation.
INTERNATIONAL STANDARD ISO 16486-6:2012(E)
Plastics piping systems for the supply of gaseous fuels —
Unplasticized polyamide (PA-U) piping systems with fusion
jointing and mechanical jointing —
Part 6:
Code of practice for design, handling and installation
1 Scope
This part of ISO 16486 specifies a code of practice dealing with unplasticized polyamide (PA-U) piping systems,
intended to be buried outside buildings and used for the supply of gaseous fuels. It addresses the common
basic principles for gas supply systems.
More detailed national standards or codes of practice might exist in the ISO member countries. This part of
ISO 16486 is intended to be applied in association with those national standards or codes of practice related
to the above-mentioned basic principles.
It is applicable to mains and service lines, the components of which are prepared for jointing by scraping and/or
machining, and gives instructions for the design, storage, handling, transportation, laying conditions and fusion
quality control of PA-U pipes and fittings up to and including 250 mm outside diameter, as well as subsequent
joint testing, backfilling, pipe system testing, commissioning and decommissioning.
The jointing methods covered by this part of ISO 16486 are butt fusion jointing and electrofusion jointing.
No special precautions are necessary for areas exposed to the influence of mining and earthquakes other than
those precautions mentioned in this part of ISO 16486.
It is the responsibility of users of this part of ISO 16486 to take existing and new national regulations into account.
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 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification,
designation and design coefficient
ISO 12176-1, Plastics pipes and fittings — Equipment for fusion jointing polyethylene systems — Part 1: Butt fusion
ISO 12176-2, Plastics pipes and fittings — Equipment for fusion jointing polyethylene systems — Part 2:
Electrofusion
ISO 12176-3, Plastics pipes and fittings — Equipment for fusion jointing polyethylene systems — Part 3:
Operator’s badge
EN 12327, Gas supply systems — Pressure testing, commissioning and decommissioning procedures —
Functional requirements
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, 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
3 Terms and definitions
For the purposes of this document, the terms, definitions, symbols and abbreviated terms given in ISO 16486-1
and ISO 16486-5 and the following apply.
3.1
butt fusion machine pressure
pressure indicated on the manometer or on a pressure display on a butt fusion machine, giving an indication of
the interface force applied to the pipe or fitting ends
3.2
clearance
shortest distance between the outer limits of two objects
3.3
drag resistance
frictional resistance due to the weight of the length of pipe fixed in the moveable clamp at the point at which
movement of the moveable clamp is initiated (peak drag), or the friction occurring during movement (dynamic drag)
3.4
electrofusion control box
unit implementing the output fusion parameters of voltage or current and time or energy to execute the fusion
cycle as specified by the electrofusion fitting manufacturer
3.5
frictional losses in the butt fusion machine
force necessary to overcome friction in the whole mechanism of a butt fusion machine
3.6
interface force
force between the fusion surfaces of the pipe(s) and/or fitting(s) during the fusion cycle, as specified in the
fusion diagram
3.7
operator
person authorized to build PA-U systems from pipes and/or fittings, based on a written procedure agreed by
the pipeline operator
3.8
pipeline operator
private or public organization authorized to design, construct or operate and maintain a gas supply system
3.9
soil cover
vertical distance between the top of a buried pipe and the normal surface after finishing work
4 Symbols and abbreviated terms
C design coefficient
CRS categorized required strength
d outside diameter of pipe at any point
e
2 © ISO 2012 – All rights reserved
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