EN ISO 23856:2021

SLOVENSKI STANDARD
01-september-2021
Nadomešča:
SIST EN 14364:2013
SIST EN 1796:2013
Cevni sistemi iz polimernih materialov za odvodnjavanje ali kanalizacijo in oskrbo
z vodo, s tlakom in brez njega - S steklenimi vlakni ojačeni duromerni materiali
(GRP) na osnovi nenasičene poliestrske smole (UP) (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 (ISO 23856:2021)
Kunststoff-Rohrleitungssysteme für Wasserversorgung, Entwässerungssysteme und
Abwasserleitungen mit und ohne Druck - Glasfaserverstärkte duroplastische Kunststoffe
(GFK) auf der Basis von ungesättigtem Polyesterharz (UP) (ISO 23856:2021)
Systèmes de canalisations en matières plastiques pour l'alimentation en eau, les
branchements et les collecteurs d'assainissement avec ou sans pression - Systèmes en
plastiques thermodurcissables renforcés de verre (PRV) à base de résine de polyester
non saturé (UP) (ISO 23856:2021)
Ta slovenski standard je istoveten z: EN ISO 23856:2021
ICS:
23.040.05 Cevovodi za zunanje Pipeline and its parts for
sisteme za odpadno vodo in external sewage systems
njihovi deli
83.120 Ojačani polimeri Reinforced plastics
91.140.60 Sistemi za oskrbo z vodo Water supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 23856
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2021
EUROPÄISCHE NORM
ICS 23.040.20; 91.140.80; 93.030 Supersedes EN 1796:2013, EN 14364:2013
English Version
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 (ISO 23856:2021)
Systèmes de canalisations en matières plastiques pour Kunststoff-Rohrleitungssysteme für
l'alimentation en eau, les branchements et les Wasserversorgung, Entwässerungssysteme und
collecteurs d'assainissement avec ou sans pression - Abwasserleitungen mit und ohne Druck -
Systèmes en plastiques thermodurcissables renforcés Glasfaserverstärkte duroplastische Kunststoffe (GFK)
de verre (PRV) à base de résine de polyester non auf der Basis von ungesättigtem Polyesterharz (UP)
saturé (UP) (ISO 23856:2021) (ISO 23856:2021)
This European Standard was approved by CEN on 16 May 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23856:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 23856:2021) has been prepared by Technical Committee ISO/TC 138 "Plastics
pipes, fittings and valves for the transport of fluids" in collaboration with Technical Committee CEN/TC
155 “Plastics piping systems and ducting systems” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2021, and conflicting national standards
shall be withdrawn at the latest by December 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1796:2013 and EN 14364:2013.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 23856:2021 has been approved by CEN as EN ISO 23856:2021 without any modification.

INTERNATIONAL ISO
STANDARD 23856
First edition
2021-06
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
Systèmes de canalisations en matières plastiques pour l'alimentation
en eau, les branchements et les collecteurs d'assainissement avec ou
sans pression — Systèmes en plastiques thermodurcissables renforcés
de verre (PRV) à base de résine de polyester non saturé (UP)
Reference number
ISO 23856:2021(E)
©
ISO 2021
ISO 23856:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 23856:2021(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
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 .15
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 .16
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 . .17
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.24
5.3.1 Initial ring stiffness .24
5.3.2 Long-term creep ring stiffness .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 longitudinal tensile strength .28
5.3.6 Initial design and failure pressures for pressure pipes .30
ISO 23856:2021(E)
5.3.7 Long-term failure pressure .32
5.4 Resistance to chemical attack .33
5.4.1 General.33
5.4.2 Procedure using failure points .33
5.4.3 Procedure using specified levels of strain.34
5.4.4 Test piece length.35
5.4.5 Test solution.35
5.5 Marking .35
6 Fittings .36
6.1 All types .36
6.1.1 General.36
6.1.2 Diameter series .36
6.1.3 Nominal pressure (PN) . .36
6.1.4 Nominal stiffness (SN) .36
6.1.5 Fitting type .36
6.1.6 Mechanical characteristics of fittings .36
6.1.7 Installed leaktightness of fittings .37
6.1.8 Dimensions .37
6.2 Bends .37
6.2.1 Classification of bends .37
6.2.2 Dimensions and tolerances of bends .38
6.3 Branches .41
6.3.1 Classification of branches.41
6.3.2 Dimensions and tolerances of branches .41
6.4 Reducers .44
6.4.1 Classification of reducers .44
6.4.2 Dimensions and tolerances of reducers .44
6.5 Non-pressure saddles .46
6.5.1 Classification of saddles .46
6.5.2 Dimensions of saddles and associated tolerances .47
6.6 Flanges .47
6.6.1 Classification of flanges .47
6.6.2 Dimensions and tolerances for adaptors .48
6.7 Marking .49
7 Joints .50
7.1 General .50
7.1.1 Interchangeability . . .50
7.1.2 Requirements .50
7.1.3 Test temperature .51
7.1.4 Non-pressure joints .51
7.1.5 Dimensions .51
7.2 Flexible joints .51
7.2.1 General.51
7.2.2 Maximum allowable draw .51
7.2.3 Maximum allowable angular deflection .51
7.2.4 Flexible non-end-load-bearing joints with elastomeric sealing rings .51
7.2.5 Flexible end-load-bearing joints with elastomeric sealing rings .52
7.3 Rigid joints .52
7.3.1 Wrapped or cemented . .52
7.3.2 Bolted flange joints .53
7.4 Marking .54
Annex A (normative) Principles used to establish the design requirements based on
regression testing and consideration of the variability of the product.55
Bibliography .60
iv © ISO 2021 – All rights reserved

ISO 23856:2021(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 of 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 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,
in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/
TC 155, Plastics piping systems and ducting systems, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This first edition cancels and replaces ISO 10639:2017 (second edition) and ISO 10467:2018 (second
edition), which have been technically revised.
The main changes compared to the previous editions are as follows:
— documents combined;
— editorial changes throughout.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
ISO 23856:2021(E)
Introduction
This document has been produced by merging ISO 10639, ISO 10467, EN 1796 and EN 14364. As these
standards were almost identical, apart from the requirements for chemical resistance of sewer pipes
on the one hand, and no negative impact on water quality of drinking water pipes on the other hand, it
was decided that it would be beneficial for users to be able to refer to a single document, irrespective of
application or region.
The content of this document is summarized as follows:
Clause 4 specifies the general aspects of GRP UP piping systems.
Clause 5 specifies the characteristics of pipes made from GRP UP with or without aggregates and/or
fillers. The pipes can have a thermoplastics or thermosetting resin liner. Clause 5 also specifies the test
parameters for the test methods referred to in this document. For pipes intended for sewer applications,
the resistance to chemical attack is stated in 5.4. For other applications, the requirements in 5.3.4 apply.
Clause 6 specifies the characteristics of fittings made from GRP UP, with or without a thermoplastics or
thermosetting resin liner. 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 joints to be used in the GRP UP piping systems, 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.
vi © ISO 2021 – All rights reserved

INTERNATIONAL STANDARD ISO 23856:2021(E)
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
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, drainage and sewerage with or without pressure. Types of water supply include, but are
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 ISO 10467 and ISO 10639, which are replaced by this document, are 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 circular 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, sewage and drainage at normal
service conditions, with or without pressure.
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 23856:2021(E)
ISO 1452-3, Plastics piping systems for water supply and for buried and above-ground drainage and
sewerage under pressure — Unplasticized poly(vinyl chloride) (PVC-U) — Part 3: Fittings
ISO 2394:2015, General principles on 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, Glass-reinforced thermosetting plastics (GRP) pipes — Determination of initial 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 8521:2020, Glass-reinforced thermosetting plastic (GRP) pipes — Test methods for the determination
of the initial circumferential tensile wall strength
ISO 8533, Glass-reinforced thermosetting plastics (GRP) pipes and fittings — 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 ring creep
properties under wet or dry conditions
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 10952, Plastics piping systems — Glass-reinforced thermosetting plastics (GRP) pipes and fittings —
Determination of the resistance to chemical attack for the inside of a section in a deflected condition
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
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
2 © ISO 2021 – All rights reserved

ISO 23856:2021(E)
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
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 (3.18) 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
mean diameter
d
m
diameter of the circle corresponding to the middle of the pipe wall cross-section and given by either of
the following formulae:
dd=+e
mi
dd=−e
m e
where
d is the internal diameter, in mm;
i
d is the external diameter, in mm;
e
e is the wall thickness of the pipe, in mm.
Note 1 to entry: It is expressed in millimetres (mm).
3.4
laying length
L
total length (3.20) of a pipe minus or plus, as applicable, the manufacturer's recommended insertion
depth of the spigot(s) in the socket
Note 1 to entry: See Figure 1.
ISO 23856:2021(E)
a)  For pipes with double bell coupling
b)  For pipes with integrated joints
Key
L laying length
Figure 1 — Laying length
3.5 Joint movement
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 2.
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), on
the pipe and a supported coupling causing a step between the two pipe spigots at the loading position
Note 1 to entry: It is expressed in millimetres (mm).
Note 2 to entry: See Figure 2.
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 2.
4 © ISO 2021 – All rights reserved

ISO 23856:2021(E)
3.5.4
flexible joint
joint which allows relative movement between the components being joined
Note 1 to entry: Examples of this type of joint are:
a) socket-and-spigot joints with an elastomeric sealing element (including double-socket designs) (non-end-
load-bearing);
b) locked socket-and-spigot joints with an elastomeric sealing element (including double-socket designs)
(either end-load-bearing or not);
c) mechanically clamped joints, e.g. bolted couplings including components made of materials other than GRP
(either end-load-bearing or not).
3.5.5
rigid joint
joint which does not allow relative movement between the components being joined
Note 1 to entry: Examples of this type of joint are:
a) flanged joints including integral or loose ring flanges;
b) wrapped or cemented joints.
Both a) and b) can be either end-load-bearing or not.
a) Draw
b) Angular deflection
ISO 23856:2021(E)
c)  Total draw
d)  Deformation
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 2 — Joint movements
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 2.
3.6
nominal size
DN
alphanumerical designation of size, 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 for 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
6 © ISO 2021 – All rights reserved

ISO 23856:2021(E)
3.10
pressure pipe or fitting
pipe or fitting subjected to an internal pressure greater than 1 bar
Note 1 to entry: Pressure pipes and fittings are classified as:
a) non-end-load-bearing pressure pipes and fittings are designed to resist internal pressure without hydraulic
end thrust
b) end-load-bearing pressure pipes and fittings are designed to resist internal pressure, including hydraulic
end thrust
3.11
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, see 3.14 and 4.5.1.
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 pressure, which is the maximum sustained hydraulic internal pressure
for which a pipe is designed in the absence of other loading conditions than internal pressure
Note 1 to entry: The designation for reference or marking purposes consists of the lette
...