SIST EN ISO 15493:2003

SLOVENSKI STANDARD
SIST EN ISO 15493:2003
01-oktober-2003
&HYQLVLVWHPLL]SROLPHUQLKPDWHULDORY]DXSRUDERYLQGXVWULML$NULORQLWULO
EXWDGLHQVWLOHQ$%6QHPHKþDQSROLYLQLONORULG39&8LQNORULUDQSROLYLQLONORULG
39&&=DKWHYH]DGHOHFHYRYRGDLQFHYQLVLVWHP0HWULþQHVHULMH,62

Plastics piping systems for industrial applications - Acrylonitrile-butadiene-styrene (ABS),
unplasticized poly(vinyl chloride) (PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) -
Specifications for components and the system - Metric series (ISO 15493:2003)
Kunststoff-Rohrleitungssysteme für industrielle Anwendungen - Acrylnitril-Butadien-Styrol
(ABS), weichmacherfreies Polyvinylchlorid (PVC-U) und chloriertes Polyvinylchlorid
(PVC-C) - Anforderungen an Rohrleitungsteile und das Rohrleitungssystem - Metrische
Reihen (ISO 15493:2003)
Systemes de canalisations en matieres plastiques pour les applications industrielles -
Acrylonitrile-butadiene-styrene (ABS) poly(chlorure de vinyle) non plastifié (PVC-U) et
poly(chlorure de vinyle) chloré (PVC-C) - Spécifications pour les composants et le
systeme - Série métrique (ISO 15493:2003)
Ta slovenski standard je istoveten z: EN ISO 15493:2003
ICS:
23.040.01
SIST EN ISO 15493:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD
EN ISO 15493
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2003
ICS 23.040.01
English version
Plastics piping systems for industrial applications - Acrylonitrile-
butadiene-styrene (ABS), unplasticized poly(vinyl chloride)
(PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) -
Specifications for components and the system - Metric series
(ISO 15493:2003)
Systèmes de canalisations en matières plastiques pour les Kunststoff-Rohrleitungssysteme für industrielle
applications industrielles - Acrylonitrile-butadiène-styrène Anwendungen - Acrylnitril-Butadien-Styrol (ABS),
(ABS) poly(chlorure de vinyle) non plastifié (PVC-U) et weichmacherfreies Polyvinylchlorid (PVC-U) und chloriertes
poly(chlorure de vinyle) chloré (PVC-C) - Spécifications Polyvinylchlorid (PVC-C) - Anforderungen an
pour les composants et le système - Série métrique (ISO Rohrleitungsteile und das Rohrleitungssystem - Metrische
15493:2003) Reihen (ISO 15493:2003)
This European Standard was approved by CEN on 11 March 2003.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15493:2003 E
worldwide for CEN national Members.

---------------------- Page: 2 ----------------------

EN ISO 15493:2003 (E)
CORRECTED  2003-07-16
Foreword
This document (EN ISO 15493:2003) 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 October 2003, and conflicting national
standards shall be withdrawn at the latest by October 2003.
This document has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association, and supports essential requirements of EU
Directive(s).
For relationship with EU Directive(s), see informative Annex ZB, which is an integral part of this
document.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and
the United Kingdom.
Endorsement notice
The text of ISO 15493:2003 has been approved by CEN as EN ISO 15493:2003 without any
modifications.
NOTE Normative references to International Standards are listed in annex ZA (normative).
2

---------------------- Page: 3 ----------------------

EN ISO 15493:2003 (E)
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated
by (mod.), the relevant EN/HD applies.
Publication Year Title EN/HD Year
ISO 228-1 2000 Pipe threads where pressure-tight EN ISO 228-1 2003
joints are not made on the threads -
Part 1: Dimensions, tolerances and
designation
ISO 306 1994 Plastics - Thermoplastic materials - EN ISO 306 1996
Determination of Vicat softening
temperature (VST)
ISO 472 1999 Plastics - Vocabulary EN ISO 472 2001
ISO 1043-1 2001 Plastics - Symbols and abbreviated EN ISO 1043-1 2001
terms - Part 1: Basic polymers and their
special characteristics
ISO 1158 1998 Plastics - Vinyl chloride homopolymers EN ISO 1158 1998
and copolymers - Determination of
chlorine content
ISO 9080 2003 Plastics piping and ducting systems - EN ISO 9080 2003
Determination of the long-term
hydrostatic strength of thermoplastics
materials in pipe form by extrapolation
ISO 12162 1995 Thermoplastics materials for pipes and EN ISO 12162 1995
fittings for pressure applications -
Classification and designation - Overall
service (design) coefficient
3

---------------------- Page: 4 ----------------------

EN ISO 15493:2003 (E)
Annex ZB
(informative)
Clauses of this Standard addressing essential requirements or other
provisions of EU Directives
This Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association. The following clauses of this standard mentioned in
this annex meet the requirements of the mandate given by EU Directive for Pressure Equipment
97/23/EC (PED).
WARNING: Other requirements and other EU Directives may be applicable to the
products falling within the scope of this standard.
Table ZA.1 - Clauses of this Standard addressing essential requirements of EU Directive
97/23/EC (PED)
Clause Requirement Clause of Annex I of the
PED
Annexes A, B and C Design for adequate strength 2.2.1
12 Permanent jointing 3.1.2
17 Traceability 3.1.5
8 and 12 Hydrostatic test pressure 3.2.2 and 7.4
5, 6 and 7 Materials 4.1, 4.2 a)
14 and 15 Design of piping system 6
Annexes A, B and C Allowable stresses 7
Compliance with these clauses of this standard provides one means of conforming with the
specific essential requirements of the EU Directive concerned and associated EFTA regulations.
NOTE Requirements of those clauses of Annex I of the PED that are not listed in Table ZA. 1
- are not applicable to components in accordance with this standard;
- could be applicable to the pressure equipment and have to be respected by the
industrial plant manufacturer and/or by the user of the components.
4

---------------------- Page: 5 ----------------------

INTERNATIONAL ISO
STANDARD 15493
First edition
2003-04-15


Plastics piping systems for industrial
applications — Acrylonitrile-butadiene-
styrene (ABS), unplasticized poly(vinyl
chloride) (PVC-U) and chlorinated
poly(vinyl chloride) (PVC-C) —
Specifications for components and the
system ― Metric series
Systèmes de canalisations en matières plastiques pour les applications
industrielles — Acrylonitrile-butadiène-styrène (ABS), poly(chlorure de
vinyle) non plastifié (PVC-U) et poly(chlorure de vinyle) chloré (PVC-C) —
Spécifications pour les composants et le système ― Série métrique




Reference number
ISO 15493:2003(E)
©
 ISO 2003

---------------------- Page: 6 ----------------------

ISO 15493:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not
be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this
file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this
area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2003 – All rights reserved

---------------------- Page: 7 ----------------------

ISO 15493:2003(E)
Contents Page
Foreword . iv
Introduction. v
1 Scope. 1
2 Normative references. 2
3 Terms and definitions. 4
4 Symbols and abbreviated terms. 7
5 Material. 8
6 General characteristics. 10
7 Geometrical characteristics . 10
8 Mechanical characteristics. 11
9 Physical characteristics . 11
10 Chemical characteristics. 12
11 Adhesives . 12
12 Performance requirements. 12
13 Classification of components . 13
14 Design of a thermoplastics piping system for industrial applications. 13
15 Installation of piping systems. 13
16 Declaration of compliance. 14
17 Marking. 14
Annex A (normative) Specific characteristics and requirements for industrial piping systems made
from acrylonitrile-butadiene-styrene (ABS). 16
Annex B (normative) Specific characteristics and requirements for industrial piping systems made
from unplasticized poly(vinyl chloride) (PVC-U). 30
Annex C (normative) Specific characteristics and requirements for industrial piping systems made
from chlorinated poly(vinyl chloride) (PVC-C) . 44
Bibliography. 62

© ISO 2003 – All rights reserved iii

---------------------- Page: 8 ----------------------

ISO 15493:2003(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15493 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the transport
of fluids, Subcommittee SC 3, Plastics pipes and fittings for industrial applications.
This document has been prepared under a mandate given by the European Commission and the European Free
Trade Association and supports essential requirements of EU Directives.
At the date of publication of this International Standard, the following standards had been published for piping
systems, used for industrial applications, made from other types of plastic:
ISO 10931 (all parts), Plastics piping systems for industrial applications — Poly(vinylidene fluoride) (PVDF)
ISO 15494, Plastics piping systems for industrial applications — Polybutene (PB), polyethylene (PE) and
polypropylene (PP) — Specifications for components and the system — Metric series.
Annexes A, B and C form a normative part of this International Standard.
iv © ISO 2003 – All rights reserved

---------------------- Page: 9 ----------------------

ISO 15493:2003(E)
Introduction
This International Standard specifies the characteristics and requirements for a piping system and its components
made from acrylonitrile-butadiene-styrene (ABS), unplasticized poly(vinyl chloride) (PVC-U) or chlorinated
poly(vinyl chloride) (PVC-C), as applicable, intended to be used for industrial applications above ground by
authorities, design engineers, certification bodies, inspection bodies, test laboratories, manufacturers and users.
© ISO 2003 – All rights reserved v

---------------------- Page: 10 ----------------------

INTERNATIONAL STANDARD ISO 15493:2003(E)

Plastics piping systems for industrial applications — Acrylonitrile-
butadiene-styrene (ABS), unplasticized poly(vinyl chloride)
(PVC-U) and chlorinated poly(vinyl chloride) (PVC-C) —
Specifications for components and the system ― Metric series
1 Scope
This International Standard specifies the characteristics and requirements for components such as pipes, fittings
and valves made from one of the following materials:
 acrylonitrile-butadiene-styrene (ABS);
 unplasticized poly(vinyl chloride) (PVC-U);
 chlorinated poly(vinyl chloride) (PVC-C);
intended to be used for thermoplastics piping systems in above-ground industrial applications.
This International Standard is applicable to ABS, PVC-U or PVC-C pipes, fittings, valves and ancillary equipment,
to their joints and to joints with components made of other plastics and non-plastics materials, depending on their
suitability, intended to be used for the conveyance of liquid and gaseous fluids as well as of solid matter in fluids for
industrial applications such as:
 chemical plants;
 industrial sewerage engineering;
 power engineering (cooling and general-purpose water supply);
 electroplating and pickling plants;
 the semiconductor industry;
 agricultural production plants;
 water treatment.
NOTE 1 Where relevant, national regulations for specific applications (e.g. water treatment) apply.
Other application areas are permitted if the requirements of this International Standard and/or applicable national
requirements are fulfilled.
Relevant regulations in respect of fire behaviour and explosion risk are applicable if applications are envisaged for
inflammable media.
The components have to withstand the mechanical, thermal and chemical demands to be expected and have to be
resistant to the fluids to be conveyed.
© ISO 2003 – All rights reserved 1

---------------------- Page: 11 ----------------------

ISO 15493:2003(E)
Characteristics and requirements which are applicable to all three materials (ABS, PVC-U and PVC-C) are covered
by the relevant clauses of this International Standard. Those characteristics and requirements which are dependent
on the material are given for each material in the relevant annex (see Table 1).
Table 1 — Material-specific annexes
Material Annex
Acrylonitrile-butadiene-styrene (ABS) A
Unplasticized poly(vinyl chloride) (PVC-U) B
Chlorinated poly(vinyl chloride) (PVC-C) C

NOTE 2 Components conforming to any of the product standards listed in the bibliography or to national standards, as
applicable, may be used with components conforming to this International Standard provided they conform to the requirements
for joint dimensions and to the other relevant requirements of this standard.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 7-1, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances and
designation
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions, tolerances
and designation
ISO 265-1, Pipes and fittings of plastics materials — Fittings for domestic and industrial waste pipes — Basic
dimensions: Metric series — Part 1: Unplasticized poly(vinyl chloride) (PVC-U)
ISO 306, Plastics — Thermoplastic materials — Determination of Vicat softening temperature (VST)
ISO 472, Plastics — Vocabulary
1)
ISO 580:— , Injection-moulded unplasticized poly(vinyl chloride) (PVC-U) fittings — Oven test — Test method and
basic specifications
ISO 727-1, Fittings made from unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C)
or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure — Part 1: Metric series
ISO 1043-1, Plastics — Symbols and abbreviated terms — Part 1: Basic polymers and their special characteristics
ISO 1158, Plastics — Vinyl chloride homopolymers and copolymers — Determination of chlorine content
ISO 1167:1996, Thermoplastics pipes for the conveyance of fluids — Resistance to internal pressure — Test
method

1) To be published. (Revision of ISO 580:1990)
2 © ISO 2003 – All rights reserved

---------------------- Page: 12 ----------------------

ISO 15493:2003(E)
ISO 1183-2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density gradient
column method
ISO 2505-1:1994, Thermoplastics pipes — Longitudinal reversion — Part 1: Determination methods
ISO 2505-2:1994, Thermoplastics pipes — Longitudinal reversion — Part 2: Determination parameters
ISO 2507-1, Thermoplastics pipes and fittings — Vicat softening temperature — Part 1: General test method
ISO 2507-2, Thermoplastics pipes and fittings — Vicat softening temperature — Part 2: Test conditions for
unplasticized poly(vinyl chloride) (PVC-U) or chlorinated poly(vinyl chloride) (PVC-C) pipes and fittings and for high
impact resistance poly(vinyl chloride) (PVC-HI) pipes
ISO 3126, Plastics piping systems — Plastics piping components — Measurement and determination of dimensions
ISO 3127, Thermoplastics pipes — Determination of resistance to external blows — Round-the-clock method
ISO 3514, Chlorinated polyvinyl chloride (CPVC) pipes and fittings — Specification and determination of density
ISO 4065, Thermoplastics pipes — Universal wall thickness table
ISO 9080, Plastics piping and ducting systems — Determination of the long-term hydrostatic strength of
thermoplastics materials in pipe form by extrapolation
ISO 9311-1, Adhesives for thermoplastics piping systems — Part 1: Determination of film properties
ISO 9852, Unplasticized poly(vinyl chloride) (PVC-U) pipes — Dichloromethane resistance at specified temperature
(DCMT) — Test method
ISO 9853, Injection-moulded unplasticized poly(vinyl chloride) (PVC-U) fittings for pressure pipe systems —
Crushing test
ISO/TR 10358, Plastics pipes and fittings — Combined chemical-resistance classification table
ISO 11922-1:1997, Thermoplastics pipes for the conveyance of fluids — Dimensions and tolerances — Part 1:
Metric series
ISO 12092, Fittings, valves and other piping system components made of unplasticized poly(vinyl chloride)
(PVC-U), chlorinated poly(vinyl chloride) (PVC-C), acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-
acrylester (ASA) for pipes under pressure — Resistance to internal pressure — Test method
ISO 12162, Thermoplastics materials for pipes and fittings for pressure applications — Classification and
designation — Overall service (design) coefficient
ISO 15853, Thermoplastics materials — Preparation of tubular test pieces for the determination of the hydrostatic
strength of materials used for injection moulding
2)
ISO 16135:— , Industrial valves — Ball valves of thermoplastics materials
2)
ISO 16136:— , Industrial valves — Butterfly valves of thermoplastics materials
2)
ISO 16137:— , Industrial valves — Check valves of thermoplastics materials
2)
ISO 16138:— , Industrial valves — Diaphragm valves of thermoplastics materials
2)
ISO 16139:— , Industrial valves — Gate valves of thermoplastics materials
2)
ISO 21787:— , Industrial valves — Globe valves of thermoplastics materials

2) To be published.
© ISO 2003 – All rights reserved 3

---------------------- Page: 13 ----------------------

ISO 15493:2003(E)
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 472 and ISO 1043-1 and the
following apply.
3.1 Geometrical definitions
NOTE The symbols d and e correspond to d and e given in other International Standards such as ISO 11922-1.
e ey y
3.1.1
nominal outside diameter
d
n
specified outside diameter of a component, which is identical to the minimum mean outside diameter, d , in
em,min
millimetres
NOTE The nominal inside diameter of a socket is equal to the nominal outside diameter of the corresponding pipe.
3.1.2
outside diameter at any point
d
e
outside diameter measured through the cross-section at any point on a pipe, or the spigot end of a fitting, rounded
up to the nearest 0,1 mm
3.1.3
mean outside diameter
d
em
measured length of the outer circumference of a pipe, or the spigot end of a fitting, divided by π (≈ 3,142), rounded
up to the nearest 0,1 mm
3.1.4
mean inside diameter of a socket
d
im
arithmetic mean of two measured inside diameters perpendicular to each other
3.1.5
nominal size of flange
DN
numerical designation for the size of a flange for reference purposes, related to the manufactured dimension in
millimetres
3.1.6
out-of-roundness
difference between the measured maximum outside diameter and the measured minimum outside diameter in the
same cross-sectional plane of a pipe, or the spigot end of a fitting, or the difference between the measured
maximum inside diameter and the measured minimum inside diameter in the same cross-sectional plane of a
socket
3.1.7
nominal wall thickness
e
n
wall thickness, in millimetres, corresponding to the minimum wall thickness, e
min
3.1.8
wall thickness at any point
e
measured wall thickness at any point around the circumference of a component, rounded up to the nearest 0,1 mm
4 © ISO 2003 – All rights reserved

---------------------- Page: 14 ----------------------

ISO 15493:2003(E)
3.1.9
pipe series
S
dimensionless number related to the nominal outside diameter, d , and the nominal wall thickness, e
n n
NOTE 1 The pipe series S is related to the pipe geometry as shown in equation (1):
de−
nn
S = (1)
2e
n
NOTE 2 Flanges are designated on the basis of PN.
3.1.10
standard dimension ratio
SDR
ratio of the nominal outside diameter, d , of a pipe to its nominal wall thickness, e
n n
NOTE In accordance with ISO 4065, the standard dimension ratio SDR and the pipe series S are related as shown in
equation (2):
SDR = 2S + 1 (2)
3.2 Definitions of materials
3.2.1
virgin material
material in a form such as granules or powder that has not been previously processed other than for compounding
and to which no reprocessable or recyclable materials have been added
3.2.2
reprocessable material
material prepared from clean unused rejected pipes, fittings or valves, produced in a manufacturer's plant by a
process such as moulding or extrusion, which will be reprocessed in the same plant and for which the complete
formulation or material specification is known
NOTE 1 Such material may include trimmings from the production of such pipes, fittings and valves.
NOTE 2 In the case of valves, only those thermoplastics parts which are made from material conforming to this International
Standard may be considered as reprocessable material.
3.3 Definitions related to material characteristics
3.3.1
lower confidence limit
σ
LCL
quantity with the dimensions of stress, expressed in megapascals, which can be considered as a property of the
material and represents the 97,5 % lower confidence limit of the predicted long-term hydrostatic strength at a given
temperature, T, and time, t, determined by pressurizing internally with water
3.3.2
minimum required strength
MRS
value of σ at 20 °C and 50 years, rounded down to the next lower value in the R 10 series when σ is less
LCL LCL
than 10 MPa, or to the next lower value in the R 20 series when σ is greater than or equal to 10 MPa
LCL
NOTE The R 10 and R 20 series are the Renard number series as defined in ISO 3 and ISO 497.
© ISO
...