ISO 10639:2017

Plastics piping systems for pressure and non-pressure water supply - Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin

ISO 10639:2017 specifies the properties of piping system components made from glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP). It is suited for all types of water supply with or without pressure, including, but not limited to, raw water, irrigation, cooling water, potable water, salt water, sea water, penstocks in power plants, processing plants and other water-based applications. ISO 10639:2017 is applicable to GRP UP piping systems, with flexible or rigid joints with or without end thrust load-bearing capability, primarily intended for use in direct buried installations. NOTE 1 For the purpose of ISO 10639:2017, the term polyester resin (UP) also includes vinyl-ester resins (VE). NOTE 2 Piping systems conforming to ISO 10639:2017 can also be used for non-buried applications, provided the influence of the environment and the supports are considered in the design of the pipes, fittings and joints. NOTE 3 ISO 10639:2017t can also apply for other installations, such as slip-lining rehabilitation of existing pipes. NOTE 4 ISO 10639:2017 is also referenced in ISO 25780, which specifies requirements for GRP-pipes used for jacking installation. The requirements for the hydrostatic pressure design of pipes referring to ISO 10639:2017 meet the requirements of ISO/TS 20656‑1 and the general principle for the reliability of structures detailed in ISO 2394 and in EN 1990. These International Standards provide procedures for the harmonization of design practices and address the probability of failure, as well as possible consequences of failures. The design practices are based on a partial safety factor concept, as well as on risk management engineering. ISO 10639:2017 is applicable to pipes, fittings and their joints of nominal sizes from DN 50 to DN 4000 which are intended to be used for the conveyance of water at temperatures up to 50 °C, with or without pressure. In a pipework system, pipes and fittings of different nominal pressure and stiffness ratings may be used together. Clause 4 specifies the general aspects of GRP UP piping systems intended to be used in the field of water supply with or without pressure. Clause 5 specifies the characteristics of pipes made from GRP UP with or without aggregates and/or fillers. The pipes may have a thermoplastics or thermosetting resin liner. Clause 5 also specifies the test parameters for the test methods referred to in ISO 10639:2017. Clause 6 specifies the characteristics of fittings made from GRP UP, with or without a thermoplastics or thermosetting resin liner, intended to be used for conveyance of water. Clause 6 specifies the dimensional and performance requirements for bends, branches, reducers, saddles and flanged adaptors. Clause 6 covers requirements to prove the structural design of fittings. It is applicable to fittings made using any of the following techniques: - fabrication from straight pipes; - moulding by filament winding, tape winding, contact moulding, and hot or cold compression moulding. Clause 7 is applicable to the joints to be used in GRP UP piping systems to be used for the conveyance of water, both buried and non-buried. It covers requirements to prove the design of the joint. Clause 7 specifies type test performance requirements for the following joints as a function of the declared nominal pressure rating of the pipeline or system: a) socket-and-spigot (including double-socket) joints or mechanical joints; b) locked socket-and-spigot joints; c) cemented or wrapped joints; d) bolted flange joints.

Systèmes de canalisation en matières plastiques pour l'alimentation en eau avec ou sans pression — Systèmes en plastiques thermodurcissables renforcés de verre (PRV) à base de résine de polyester non saturé (UP)

General Information

• Status: Withdrawn
• Publication Date: 11-Oct-2017
• Withdrawal Date: 11-Oct-2017
• ICS: 23.040.20 - Plastics pipes
• ICS: 91.140.60 - Water supply systems
• ICS: 93.025 - External water conveyance systems
• Technical Committee: ISO/TC 138/SC 6 - Reinforced plastics pipes and fittings for all applications
• Drafting Committee: ISO/TC 138/SC 6/WG 3 - Specifications for pipe systems
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 15-Jun-2021
• Completion Date: 13-Dec-2025

Relations

• Revised: ISO 23856:2021 - Plastics piping systems for pressure and non-pressure water supply, drainage or sewerage - Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin
• Effective Date: 14-Oct-2020
• Revises: ISO 10639:2004/Amd 1:2011 - Plastics piping systems for pressure and non-pressure water supply - Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin - Amendment 1
• Effective Date: 02-Nov-2013
• Revises: ISO 10639:2004 - Plastics piping systems for pressure and non-pressure water supply - Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin
• Effective Date: 02-Nov-2013

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10639
Second edition
2017-10
Plastics piping systems for pressure
and non-pressure water supply —
Glass-reinforced thermosetting
plastics (GRP) systems based on
unsaturated polyester (UP) resin
Systèmes de canalisation en matières plastiques pour l'alimentation
en eau avec ou sans pression — Systèmes en plastiques
thermodurcissables renforcés de verre (PRV) à base de résine de
polyester non saturé (UP)
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 3
4 General .12
4.1 Classification .12
4.1.1 Categories .12
4.1.2 Nominal size .12
4.1.3 Nominal stiffness .12
4.1.4 Nominal pressure .12
4.2 Materials .13
4.2.1 General.13
4.2.2 Reinforcement .13
4.2.3 Resin .14
4.2.4 Aggregates and fillers .14
4.2.5 Thermoplastics liners .14
4.2.6 Elastomers .14
4.2.7 Metals .14
4.3 Wall construction .14
4.3.1 Inner layer .14
4.3.2 Structural layer .14
4.3.3 Outer layer .14
4.4 Appearance .15
4.5 Reference conditions for testing .15
4.5.1 Temperature .15
4.5.2 Properties of water for testing .15
4.5.3 Loading conditions . .15
4.5.4 Conditioning .15
4.5.5 Measurement of dimensions .15
4.6 Elapsed time, x, for determination of long-term properties .15
4.7 Joints .16
4.7.1 General.16
4.7.2 Types of joint .16
4.7.3 Flexibility of the joint .16
4.7.4 Sealing ring .16
4.7.5 Adhesives . .16
4.8 Effect on water quality .17
4.9 Assessment of conformity .17
5 Pipes .17
5.1 Type of pipes .17
5.2 Geometrical characteristics .17
5.2.1 Diameter .17
5.2.2 Wall thickness .23
5.2.3 Length.23
5.3 Mechanical characteristics.23
5.3.1 Initial specific ring stiffness .23
5.3.2 Long-term specific ring stiffness under wet conditions .24
5.3.3 Initial resistance to failure in a deflected condition .25
5.3.4 Ultimate long-term resistance to failure in a deflected condition.27
5.3.5 Initial specific longitudinal tensile strength .28
5.3.6 Initial design and failure pressures for pressure pipes .30
5.3.7 Long-term failure pressure .32
5.4 Marking .32
6 Fittings .33
6.1 All types .33
6.1.1 General.33
6.1.2 Diameter series .33
6.1.3 Nominal pressure (PN) . .33
6.1.4 Nominal stiffness (SN) .33
6.1.5 Fitting type .33
6.1.6 Mechanical characteristics of fittings .33
6.1.7 Installed leaktightness of fittings .34
6.1.8 Dimensions .34
6.2 Bends .34
6.2.1 Classification of bends .34
6.2.2 Dimensions and tolerances of bends .35
6.3 Branches .38
6.3.1 Classification of branches.38
6.3.2 Dimensions and tolerances of branches .38
6.4 Reducers .41
6.4.1 Classification of reducers .41
6.4.2 Dimensions and tolerances of reducers .41
6.5 Non pressure saddles .43
6.5.1 Classification of saddles .43
6.5.2 Dimensions of saddles and associated tolerances .44
6.6 Flanges .44
6.6.1 Classification of flanges .44
6.6.2 Dimensions and tolerances for adaptors .45
6.7 Marking .47
7 Joint performance .47
7.1 General .47
7.1.1 Interchangeability . . .47
7.1.2 Requirements .47
7.1.3 Test temperature .48
7.1.4 Non-pressure piping and joints .48
7.1.5 Dimensions .48
7.2 Flexible joints .48
7.2.1 General.48
7.2.2 Maximum allowable draw .48
7.2.3 Maximum allowable angular deflection .48
7.2.4 Flexible non-end-load-bearing joints with elastomeric sealing rings .48
7.2.5 Flexible end-load-bearing joints with elastomeric sealing rings .49
7.3 Rigid joints .49
7.3.1 Wrapped or cemented . .49
7.3.2 Bolted flange joints .50
7.4 Marking .50
Annex A (normative) Principles used to establish the design requirements based on
regression testing and consideration of the variability of the product.52
Bibliography .57
iv © ISO 2017 – All rights reserved

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 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 the following
URL: 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 6, Reinforced plastics pipes and fittings for all applications.
This second edition cancels and replaces the first edition (ISO 10639:2004), which has been technically
revised. It also incorporates the Amendment ISO 10639:2004/Amd. 1:2011.
The main changes compared to the previous edition are as follows:
— inclusion of a guidance for the harmonization of design practices which are based on a partial safety
factor concept and risk management engineering, as well as inclusion of the probability of failure
and possible consequences of failures;
— addition of references to the general principle for the reliability of structures detailed in ISO 2394
and EN 1990;
— addition of a new safety factor concept for the hydrostatic pressure design;
— addition of a clear reference for assessment of conformity;
— changes in Clause 6, including pressure tests requirements for fittings;
— changes in Clause 7;
— changes in Annex A for the establishment of the design requirements.
INTERNATIONAL STANDARD ISO 10639:2017(E)
Plastics piping systems for pressure and non-pressure
water supply — Glass-reinforced thermosetting plastics
(GRP) systems based on unsaturated polyester (UP) resin
1 Scope
This document specifies the properties of piping system components made from glass-reinforced
thermosetting plastics (GRP) based on unsaturated polyester resin (UP). It is suited for all types of
water supply with or without pressure, including, but not limited to, raw water, irrigation, cooling
water, potable water, salt water, sea water, penstocks in power plants, processing plants and other
water-based applications. This document is applicable to GRP UP piping systems, with flexible or rigid
joints with or without end thrust load-bearing capability, primarily intended for use in direct buried
installations.
NOTE 1 For the purpose of this document, the term polyester resin (UP) also includes vinyl-ester resins (VE).
NOTE 2 Piping systems conforming to this document can also be used for non-buried applications, provided
the influence of the environment and the supports are considered in the design of the pipes, fittings and joints.
NOTE 3 This document can also apply for other installations, such as slip-lining rehabilitation of existing pipes.
NOTE 4 This document is also referenced in ISO 25780, which specifies requirements for GRP-pipes used for
jacking installation.
The requirements for the hydrostatic pressure design of pipes referring to this document meet the
requirements of ISO/TS 20656-1 and the general principle for the reliability of structures detailed in
ISO 2394 and in EN 1990. These International Standards provide procedures for the harmonization of
design practices and address the probability of failure, as well as possible consequences of failures. The
design practices are based on a partial safety factor concept, as well as on risk management engineering.
This document is applicable to pipes, fittings and their joints of nominal sizes from DN 50 to DN 4000
which are intended to be used for the conveyance of water at temperatures up to 50 °C, with or without
pressure. In a pipework system, pipes and fittings of different nominal pressure and stiffness ratings
may be used together. Clause 4 specifies the general aspects of GRP UP piping systems intended to be
used in the field of water supply with or without pressure.
Clause 5 specifies the characteristics of pipes made from GRP UP with or without aggregates and/or
fillers. The pipes may have a thermoplastics or thermosetting resin liner. Clause 5 also specifies the test
parameters for the test methods referred to in this document.
Clause 6 specifies the characteristics of fittings made from GRP UP, with or without a thermoplastics or
thermosetting resin liner, intended to be used for conveyance of water. Clause 6 specifies the dimensional
and performance requirements for bends, branches, reducers, saddles and flanged adaptors. Clause 6
covers requirements to prove the structural design of fittings. It is applicable to fittings made using any
of the following techniques:
— fabrication from straight pipes;
— moulding by
1) filament winding,
2) tape winding,
3) contact moulding, and
4) hot or cold compression moulding.
Clause 7 is applicable to the joints to be used in GRP UP piping systems to be used for the conveyance
of water, both buried and non-buried. It covers requirements to prove the design of the joint. Clause 7
specifies type test performance requirements for the following joints as a function of the declared
nominal pressure rating of the pipeline or system:
a) socket-and-spigot (including double-socket) joints or mechanical joints;
b) locked socket-and-spigot joints;
c) cemented or wrapped joints;
d) bolted flange joints.
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 75-2:2013, Plastics — Determination of temperature of deflection under load — Part 2: Plastics
and ebonite
ISO 161-1, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal
pressures — Part 1: Metric series
ISO 527-4, Plastics — Determination of tensile properties — Part 4: Test conditions for isotropic and
orthotropic fibre-reinforced plastic composites
ISO 527-5, Plastics — Determination of tensile properties — Part 5: Test conditions for unidirectional fibre-
reinforced plastic composites
ISO 2394:2015, General principles on the reliability for structures
ISO 2531, Ductile iron pipes, fittings, accessories and their joints for water applications
ISO 3126, Plastics piping systems — Plastics components — Determination of dimensions
ISO 4200, Plain end steel tubes, welded and seamless — General tables of dimensions and masses per
unit length
ISO 4633, Rubber seals — Joint rings for water supply, drainage and sewerage pipelines — Specification for
materials
ISO 7432, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — Test methods to prove the
design of locked socket-and-spigot joints, including double-socket joints, with elastomeric seals
ISO 7509, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Determination
of time to failure under sustained internal pressure
ISO 7685, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Determination
of initial specific ring stiffness
ISO 8483, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — Test methods to prove the
design of bolted flange joints
ISO 8513:2016, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Test
methods for the determination of the initial longitudinal tensile strength
ISO 8521:2009, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Test
methods for the determination of the apparent initial circumferential tensile strength
2 © ISO 2017 – All rights reserved

ISO 8533, Plastics piping systems for pressure and non-pressure drainage and sewerage — Glass-reinforced
thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin — Test methods to prove
the design of cemented or wrapped joints
ISO 8639, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — Test methods for leaktightness
and proof of structural design of flexible joints
ISO 10466, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes — Test method
to prove the resistance to initial ring deflection
ISO 10468, Glass-reinforced thermosetting plastics (GRP) pipes — Determination of the long-term specific
ring creep stiffness under wet conditions and calculation of the wet creep factor
ISO 10471, Glass-reinforced thermosetting plastics (GRP) pipes — Determination of the long-term ultimate
bending strain and the long-term ultimate relative ring deflection under wet conditions
ISO 10928:2016, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes and
fittings — Methods for regression analysis and their use
ISO 11922-1, Thermoplastics pipes for the conveyance of fluids — Dimensions and tolerances — Part 1:
Metric series
ISO 18851, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes and fittings —
Test method to prove the structural design of fittings
ISO/TS 20656-1, Plastic piping systems — General rules for the structural design of glass-reinforced
thermosetting (GRP) pipes — Part 1: Buried pipe
CEN/TS 14632, Plastics piping systems for drainage, sewerage and water supply, pressure and non-pressure.
Glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP). Guidance for the
assessment of conformity
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
break
condition where the test piece can no longer carry the load to which it is being subjected
3.2
coefficient of variation
V
ratio of the standard deviation (3.16) to the absolute value of the arithmetic mean, given by the following
formula:
V = standard deviation of the population / mean of the population
Note 1 to entry: In this document, it is expressed as a percentage.
3.3 Diameter
3.3.1
declared diameter
diameter which a manufacturer states to be the internal or external diameter produced in respect of a
particular nominal size (DN) (3.6)
3.3.2
mean diameter
d
m
diameter of the circle corresponding to the middle of the pipe wall cross-section and given, in metres
(m), by either of the following formulae:
dd=+e
mi
dd=−e
me
where
d is the internal diameter, in m;
i
d is the external diameter, in m;
e
e is the wall thickness of the pipe, in m.
3.4
laying length
total length (3.19) of a pipe minus, where applicable, the manufacturer's recommended insertion depth
of the spigot(s) in the socket
4 © ISO 2017 – All rights reserved

3.5 Joint movement
a)
b)
c)
d
Key
D draw
J longitudinal movement arising from angular deflection of the joint
δ angular deflection of the joint
T total draw
M deformation
Figure 1 — Joint movements
3.5.1
angular deflection
δ
angle between the axes of two consecutive pipes
Note 1 to entry: It is expressed in degrees (°).
Note 2 to entry: See Figure 1.
3.5.2
deformation
M
pipe deformation in the coupling as a result of a vertical force of 20 N/mm of the nominal size (3.6), in
millimetres (mm) on the pipe and a supported coupling causing a step between the two pipe spigots at
the loading position in millimetres (mm)
Note 1 to entry: See Figure 1.
3.5.3
draw
D
longitudinal movement of a joint
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Figure 1.
3.5.4
flexible joint
joint which allows relative movement between the components being joined
Note 1 to entry: Flexible joints which have resistance to axial loading are classified as end-load-bearing. Examples
of this type of joint are:
a) socket-and-spigot joints with an elastomeric sealing element (including double-socket designs);
b) locked socket-and-spigot joints with an elastomeric sealing element (including double-socket designs);
c) mechanically clamped joints, e.g. bolted couplings including components made of materials other than GRP.
3.5.5
rigid joint
joint which does not allow relative movement between the components being joined
Note 1 to entry: Rigid joints which do not have resistance to axial loading are classified as non-end-load-bearing.
Examples of this type of joint are:
a) flanged joints including integral or loose flanges;
b) wrapped or cemented joints.
3.5.6
total draw
T
sum of the draw, D (3.5.3), and the additional longitudinal movement, J, of joint components due to the
presence of angular deflection (3.5.1)
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Figure 1.
6 © ISO 2017 – All rights reserved

3.6
nominal size
DN
alphanumerical designation of size, which is common to all components in a piping system, which
is a convenient round number for reference purposes and is related to the internal diameter in
millimetres (mm)
Note 1 to entry: The designation for reference or marking purposes consists of the letters DN plus a number.
3.7
nominal length
numerical designation of pipe length which is equal to the laying length (3.4), in metres (m), rounded to
the nearest whole number
3.8
nominal stiffness
SN
alphanumerical designation of stiffness classification purposes, which has the same numerical value as
the minimum initial value required, when expressed in newtons per square metre (N/m )
Note 1 to entry: See 4.1.3.
Note 2 to entry: The designation for reference or marking purposes consists of the letters SN plus a number.
3.9
non-pressure pipe or fitting
pipe or fitting subjected to an internal pressure not greater than 1 bar
3.10
normal service conditions
conveyance of water or sewage in the temperature range 2 °C to 50 °C, with or without pressure, for
50 years
Note 1 to entry: At temperatures above 35 °C, it may be necessary to rerate the pipe.
3.11 Pipeline
3.11.1
buried pipeline
pipeline which is subjected to the external pressure transmitted from soil loading, including traffic and
superimposed loads and possibly the pressure of a head of water
3.11.2
non-buried pipeline
pipeline which is subjected to negative and positive pressure, forces resulting from its supports and
environmental conditions
Note 1 to entry: Examples of environmental conditions are snow, wind and temperature.
3.11.3
sub-aqueous pipeline
pipeline which is subjected to an external pressure arising from a head of water and conditions such as
drag and lift caused by current and wave action
3.12 Pressure
3.12.1
initial failure pressure
p
mean pressure at which failure occurs with specimens subjected to short-term tests performed in
accordance with ISO 8521
3.12.2
nominal pressure
PN
alphanumeric designation for a nominal pressure class, which is the maximum sustained hydraulic
internal pressure for which a pipe is designed in the absence of other loading conditions than internal
pressure, this means that the nominal pressure shall be equal to or greater than the working pressure
(3.12.11)
Note 1 to entry: The designation for reference or marking purposes consists of the letters PN plus a number.
Note 2 to entry: The definition for the PN has been changed to the previous version of this document. The
definition is more specific and related to internal pressure load exclusively.
3.12.3
minimum initial failure pressure
p
0,QC
initial failure pressure (3.12.1), determined in accordance with ISO 8521, which 95 % of products are
required to exceed
3.12.4
mean design pressure
p
0,d
mean design initial failure pressure to ensure 95 % of products will exceed the initial failure pressure,
p (3.12.1)
0,QC
3.12.5
minimum safety factor for long-term pressure
FS
min
minimum safety factor for long-term pressure which is applied to the nominal pressure (PN) (3.12.2)
3.12.6
mean safety factor safety factor for long-term pressure
FS
mean
mean safety factor for long-term pressure which is applied to the nominal pressure (PN) (3.12.2)
3.12.7
minimum failure pressure at 50 years
p
50,min
95% lower confidence level (LCL) of the failure pressure after 50 years
3.12.8
pressure regression ratio
R
R,p
ratio of the projected failure pressure at 50 years, p (3.12.10), to the projected failure pressure at 6 min,
p , obtained from long-term pressure tests performed in accordance with ISO 7509 and analysed in
accordance with ISO 10928
3.12.9
pressure pipe or fitting
pipe or fitting having a nominal pressure classification, expressed in bar, greater than 1 bar and which
is intended to be used at internal pressures up to its nominal pressure (PN) (3.12.2)
Note 1 to entry: It is expressed in bar.
3.12.10
projected failure pressure at 50 years
p
value at 50 years derived from the pressure regression line obtained from long-term pressure tests
performed in accordance with ISO 7509 and analysed in accordance with ISO 10928
8 © ISO 2017 – All rights reserved

3.12.11
working pressure
p
w
maximum internal hydrostatic pressure, excluding surge, at which a system can be continuously
operated
Note 1 to entry: It is expressed in bar.
Note 2 to entry: Working pressure is represented by the following fomula:
p ≤ PN
w
where
p is the working pressure, in bar;
w
PN is the nominal pressure, in bar.
3.12.12
correction factor
C
ratio of the mean value of the tested initial failure pressure (p ) to the projected 6 min failure
0,mean
pressure (p ) calculated from the regression line
3.13
rerating factor
R
RF
multiplication factor that quantifies the relationship of a product’s mechanical, physical and chemical
properties under service conditions above 35 °C [service temperature (3.18.1)] to those applicable at a
standard test temperature of 23 °C
3.14 Ring deflection
3.14.1
extrapolated long-term relative ultimate ring deflection
y /d
u,wet,x m
deflection value at x years derived from the ultimate deflection regression line obtained from long-
term deflection tests performed under wet conditions in accordance with ISO 10471 and analysed in
accordance with ISO 10928
Note 1 to entry: For x years, see 4.6.
Note 2 to entry: It is expressed as a percentage by multiplying by 100.
3.14.2
relative ring deflection
y/d
m
ratio of the change in diameter of a pipe, y, in metres (m), to its mean diameter, d (3.3.2)
m
Note 1 to entry: See 3.3.2.
Note 2 to entry: It is derived as a percentage from the formula:
y
relative ring deflection =×100�
d
m
3.14.3
minimum initial relative specific ring deflection before bore cracking occurs
(y /d )
2,bore m min
initial relative deflection at 2 min which a test piece is required to pass without bore cracking when
tested in accordance with ISO 10466
Note 1 to entry: It is expressed as a percentage by multiplying by 100.
3.14.4
minimum initial relative specific ring deflection before structural failure occurs
(y /d )
2,struct m min
initial relative deflection at 2 min which a test piece is required to pass without structural failure when
tested in accordance with ISO 10466
Note 1 to entry: It is expressed as a percentage by multiplying by 100.
3.14.5
minimum long-term relative ultimate ring deflection
(y /d )
u,wet,x m min
required minimum extrapolated value at x years derived from the ultimate deflection regression line
obtained from long-term deflection tests performed under wet conditions in accordance with ISO 10471
Note 1 to entry: It is expressed as a percentage by multiplying by 100.
Note 2 to entry: For x years, see 4.6.
3.15 Ring stiffness
3.15.1
initial specific ring stiffness
S
value of S obtained when determined in accordance with ISO 7685
Note 1 to entry: It is expressed in newtons per square metre (N/m ).
3.15.2
long-term specific ring stiffness
S
x,wet
value of specific ring stiffness (3.15.3), S, at x years, determined in accordance with ISO 10468
Note 1 to entry: For x years, see 4.6.
3.15.3
specific ring stiffness
S
measure of the resistance, in newtons per square metre (N/m ), of a pipe to ring deflection per metre
(m) length under external load as defined by the formula:
EI×
S =
d
m
10 © ISO 2017 – All rights reserved

where
E is the apparent modulus of elasticity as determined in a ring stiffness test, in N/m ;
I is the second moment of area in the longitudinal direction per metre length, in m /m, i.e.
e
I =
where
e     is the wall thickness, in m;
d   is the mean diameter of the pipe, in m (see 3.3.2).
m
3.16
standard deviation
σ
positive square root of the variance (3.21)
3.17
surge
rapid change in internal pressure, either positive or negative, caused by a change in the flow velocity
Note 1 to entry: It is expressed in bar.
3.18 Temperature
3.18.1
service temperature
maximum sustained temperature at which a system is expected to operate
Note 1 to entry: It is expressed in degrees Celsius (°C).
Note 2 to entry: This temperature is used for the rerating of the product (see 3.13).
3.18.2
design temperature
maximum temperature at which a system can be exposed to occasionally
Note 1 to entry: It is expressed in degrees Celsius (°C).
3.19
total length
distance between two planes normal to the pipe axis and passing through the extreme end points of
the pipe
Note 1 to entry: It is expressed in metres (m).
3.20
type test
test performed to prove that the material, product, joint, fittings or assembly is capable of conforming
to the requirements given in this document
3.21
variance
measure of dispersion based on the mean square deviation from the arithmetic mean
3.22
wet creep factor
α
x,wet,creep
ratio of the long-term specific ring stiffness, S (3.15.2), at x years, determined under sustained
x,wet
loading in wet conditions in accordance with ISO 10468, to the initial specific ring stiffness, S (3.15.1),
both measured at the same position referred to as reference position 1
Note 1 to entry: For x years, see 4.6.
Note 2 to entry: It is given by the formula:
S
x,wet
α =
x,wet,creep
S
4 General
4.1 Classification
4.1.1 Categories
Pipes and fittings shall be classified according to nominal size (DN) (see 3.6), nominal pressure (PN)
(see 3.12.2) and joint type.
In addition, pipes shall include nominal stiffness (SN) (see 3.8) in their classification.
4.1.2 Nominal size
The nominal size (DN) of pipes and fittings shall conform to the appropriate tables in Clause 5. If a
thermoplastics liner is present, its internal diameter shall be declared by the manufacturer. The
tolerance on the diameter shall be as specified in Clause 5.
4.1.3 Nominal stiffness
The nominal stiffness (SN) shall conform to one of those given in Table 1 (see Note to Table 1).
Table 1 — Nominal stiffness (SN)
Nomi
...