EN 1555-2:2021

SLOVENSKI STANDARD
01-september-2021
Nadomešča:
SIST EN 1555-2:2010
Cevni sistemi iz polimernih materialov za oskrbo s plinastimi gorivi - Polietilen
(PE) - 2. del: Cevi
Plastics piping systems for the supply of gaseous fuels - Polyethylene (PE) - Part 2:
Pipes
Kunststoff-Rohrleitungssysteme für die Gasversorgung - Polyethylen (PE) - Teil 2: Rohre
Systèmes de canalisations en plastique pour la distribution de combustibles gazeux -
Polyéthylène (PE) - Partie 2 : Tubes
Ta slovenski standard je istoveten z: EN 1555-2:2021
ICS:
83.140.30 Polimerne cevi in fitingi za Plastics pipes and fittings for
snovi, ki niso tekočine non fluid use
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 1555-2
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2021
EUROPÄISCHE NORM
ICS 23.040.20 Supersedes EN 1555-2:2010
English Version
Plastics piping systems for the supply of gaseous fuels -
Polyethylene (PE) - Part 2: Pipes
Systèmes de canalisations en plastique pour la Kunststoff-Rohrleitungssysteme für die Gasversorgung
distribution de combustibles gazeux - Polyéthylène - Polyethylen (PE) - Teil 2: Rohre
(PE) - Partie 2 : Tubes
This European Standard was approved by CEN on 7 June 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 1555-2:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 Symbols and abbreviations . 8
5 Material . 8
5.1 Compound for pipes . 8
5.2 Compound for identification stripes . 8
5.3 External reworked and recycled material . 8
6 General characteristics . 9
6.1 Appearance . 9
6.2 Colour . 9
7 Geometrical characteristics . 9
7.1 Measurement of dimensions. 9
7.2 Mean outside diameters, out-of-roundness (ovality) and tolerances . 9
7.3 Wall thicknesses and related tolerances . 11
7.3.1 Minimum wall thicknesses . 11
7.3.2 Tolerance on the wall thicknesses . 12
7.4 Circumferential reversion of pipes with a dn equal to or greater than 250 mm . 14
7.5 Coiled pipe . 14
7.6 Lengths . 14
8 Mechanical characteristics . 14
8.1 Conditioning . 14
8.2 Requirements . 14
9 Physical characteristics . 18
9.1 Conditioning . 18
9.2 Requirements . 18
10 Performance requirements . 19
11 Marking . 19
11.1 General . 19
11.2 Minimum required marking . 20
11.3 Additional marking . 20
Annex A (normative) Pipes with co-extruded layers . 21
Annex B (normative) Pipes with peelable layer . 23
Annex C (normative) Squeeze-off technique . 25
Bibliography. 26

European foreword
This document (EN 1555-2:2021) has been prepared by 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 January 2022, and conflicting national standards shall
be withdrawn at the latest by January 2022.
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 1555-2:2010.
In comparison with the previous version, the following technical modifications have been introduced:
— PE 100-RC type materials with enhanced resistance to slow crack growth have been added.
— Annex A of EN 1555-1:2021 now discusses the performance of this type of material and gives
additional information for non-conventional installation techniques.
— Test methods have been updated.
— New test methods have been added for PE 100-RC materials.
It has been prepared in liaison with Technical Committee CEN/TC 234 “Gas infrastructure”.
System Standards are based on the results of the work being undertaken in ISO/TC 138 “Plastics pipes,
fittings and valves for the transport of fluids”, which is a Technical Committee of the International
Organization for Standardization (ISO).
They are supported by separate standards on test methods to which references are made throughout the
System Standard.
The System Standards are consistent with general standards on functional requirements and on
recommended practice for installation.
EN 1555 consists of the following parts:
— EN 1555-1, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 1:
General;
— EN 1555-2, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 2: Pipes
(this standard);
— EN 1555-3, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 3:
Fittings;
— EN 1555-4, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 4: Valves;
— EN 1555-5, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 5: Fitness
for purpose of the system;
— CEN/TS 1555-7, Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — Part 7:
Guidance for assessment of conformity.
NOTE EN 12007-2 [1] prepared by CEN/TC 234 “Gas infrastructure” deals with the recommended practice for
installation of plastics pipes system in accordance with EN 1555 (all parts).
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
Introduction
This document specifies the requirements for a piping system and its components made from
polyethylene (PE) and which is intended to be used for the supply of gaseous fuels.
Requirements and test methods for material and components, other than pipes, are specified in
EN 1555-1, EN 1555-3 [2] and EN 1555-4 [3].
Characteristics for fitness for purpose are covered in EN 1555-5. CEN/TS 1555-7 [4] gives guidance for
assessment of conformity. Recommended practice for installation is given in EN 12007-2 [1] prepared by
CEN/TC 234.
This part of EN 1555 covers the characteristics of pipes.
1 Scope
This document specifies the characteristics of pipes made from polyethylene (PE) for piping systems in
the field of the supply of gaseous fuels.
It also specifies the test parameters for the test methods referred to in this document.
In conjunction with Parts 1 and 3 to 5 of EN 1555, it is applicable to PE pipes, their joints and to joints
with components of PE and other materials intended to be used under the following conditions:
a) a maximum operating pressure, MOP, up to and including 10 bar at a reference temperature of 20 °C
for design purposes;
b) an operating temperature between −20 °C and 40 °C.
NOTE 1 For operating temperatures between 20 °C and 40 °C derating coefficients are defined in
EN 1555-5:2021.
EN 1555 covers a range of maximum operating pressures and gives requirements concerning colours.
It covers three types of pipe:
— PE pipes (outside diameter d ) including any identification stripes;
n
— PE pipes with co-extruded layers on either or both the outside and/or inside of the pipe (total outside
diameter d ) as specified in Annex A, where all layers have the same MRS rating. A coextruded pipe
n
made of a combination of PE 100 and PE 100-RC layers shall be regarded as PE 100 and marked
accordingly;
— PE pipes (outside diameter d ) with a peelable, contiguous thermoplastics additional layer on the
n
outside of the pipe (‘coated pipe’) as specified in Annex B.
NOTE 2 It is the responsibility of the purchaser or specifier to make the appropriate selections from these
aspects, taking into account their particular requirements and any relevant national regulations and installation
practices or codes.
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.
EN 1555-1:2021, Plastics piping systems for the supply of gaseous fuels - Polyethylene (PE) - Part 1: General
EN 1555-5:2021, Plastics piping systems for the supply of gaseous fuels - Polyethylene (PE) - Part 5: Fitness
for purpose of the system
EN 12106, Plastics piping systems - Polyethylene (PE) pipes - Test method for the resistance to internal
pressure after application of squeeze-off
EN ISO 1133-1, Plastics - Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR)
of thermoplastics - Part 1: Standard method (ISO 1133-1)

1 5 2
bar = 0,1 MPa. = 10 Pa; 1 MPa = 1 N/mm .
EN ISO 1167-1:2006, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids -
Determination of the resistance to internal pressure - Part 1: General method (ISO 1167-1:2006)
EN ISO 1167-2, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids - Determination
of the resistance to internal pressure - Part 2: Preparation of pipe test pieces (ISO 1167-2)
EN ISO 2505, Thermoplastics pipes - Longitudinal reversion - Test method and parameters (ISO 2505)
EN ISO 3126, Plastics piping systems - Plastics components - Determination of dimensions (ISO 3126)
ISO 4065, Thermoplastics pipes - Universal wall thickness table
EN ISO 6259-1, Thermoplastics pipes - Determination of tensile properties - Part 1: General test method
(ISO 6259-1)
EN ISO 6259-3:2015, Thermoplastics pipes - Determination of tensile properties - Part 3: Polyolefin pipes
(ISO 6259-3:2015)
EN ISO 9969, Thermoplastics pipes - Determination of ring stiffness (ISO 9969)
EN ISO 11357-6, Plastics - Differential scanning calorimetry (DSC) - Part 6: Determination of oxidation
induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT) (ISO 11357-6)
EN ISO 13477, Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack
propagation (RCP) - Small-scale steady-state test (S4 test) (ISO 13477)
EN ISO 13478, Thermoplastics pipes for the conveyance of fluids - Determination of resistance to rapid crack
propagation (RCP) - Full-scale test (FST) (ISO 13478)
EN ISO 13968, Plastics piping and ducting systems - Thermoplastics pipes - Determination of ring flexibility
(ISO 13968)
ISO 11922-1:2018, Thermoplastics pipes for the conveyance of fluids - Dimensions and tolerances - Part 1:
Metric series
ISO 13479:— , Polyolefin pipes for the conveyance of fluids - Determination of resistance to crack
propagation - Test method for slow crack growth on notched pipes
ISO 18488, Polyethylene (PE) materials for piping systems - Determination of Strain Hardening Modulus in
relation to slow crack growth - Test method
ISO 18489, Polyethylene (PE) materials for piping systems - Determination of resistance to slow crack
growth under cyclic loading - Cracked Round Bar test method

Under preparation. Stage at the time of publication: ISO/DIS 13479:2021.
3 Terms and definitions
For the purposes of this document the terms and definitions, symbols and abbreviations given in
EN 1555-1:2021 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
squeeze-off
gas flow stopped by squeezing the pipe when compressed between two clamps in such a way that the
distance between both clamps is less than twice the nominal wall thickness
Note 1 to entry: See Annex C.
4 Symbols and abbreviations
For the purpose of this document the symbols and abbreviations given in EN 1555-1 apply.
5 Material
5.1 Compound for pipes
The PE compound from which the pipes are made shall conform to EN 1555-1.
The pipes shall be made from virgin material or reworked material from the same PE compound from the
manufacturer’s own plant, or a mixture of both. Reworked material from the base pipe of peelable layer
pipe (coated pipe) and reworked material from pipes with identification stripes may be used.
For co-extruded layers, see Annex A.
Reworked material from coextruded pipes or from pipes reworked with the peelable layer attached shall
not be used.
5.2 Compound for identification stripes
The stripe compound (see 6.2) shall be manufactured from a PE base polymer according to EN 1555-1,
which is used for a pipe compound for which fusion compatibility has been proven.
The compound used for identification stripes shall comply with the fusion compatibility requirements in
EN 1555-1, and with the resistance to weathering as described in EN 1555-1:2021, Table 2. The
resistance to weathering of the identification stripe compound shall be declared by the manufacturer of
2 2
the compound, confirming whether either a cumulative radiant exposure of ≥ 3,5 GJ/ m or ≥ 7 GJ/m
related to the outdoor storage ability limit is applicable.
The OIT of the stripe compound shall be ≥ 20 min at 200 °C, measured by the compound supplier in
accordance with EN ISO 11357-6.
5.3 External reworked and recycled material
Reworked material obtained from external sources, and recycled material shall not be used.
6 General characteristics
6.1 Appearance
When viewed without magnification, the internal and external surfaces of pipes shall be smooth and
clean, and shall have no scoring, cavities and other surface defects to an extent that would prevent
conformity to this document.
The ends of the pipe shall be cut cleanly and square to the axis of the pipe.
6.2 Colour
Pipes shall be black (PE 80, PE 100 and PE 100-RC), yellow (PE 80) or orange (PE 100 and PE 100-RC).
In addition, black PE 80 pipes may be identified by yellow stripes and black PE 100 and PE 100-RC pipes
may be identified by yellow or orange stripes, according to national preference.
The outer coextruded layer of coextruded pipes (see Annex A) or the outer peelable layer of peelable
layer pipes (see Annex B) shall be either black, yellow or orange. In addition, identification stripes may
be used according to national preference.
NOTE National preference for colour can be stated in the national foreword.
7 Geometrical characteristics
7.1 Measurement of dimensions
The dimensions of the pipe shall be measured in accordance with EN ISO 3126, and rounded to the next
0,1 mm. In case of dispute, the measurement shall not be made less than 24 h after manufacture after
being conditioned for at least 4 h at (23 ± 2) °C.
Indirect measurement at the stage of production is allowed at shorter time periods providing evidence is
shown of correlation.
7.2 Mean outside diameters, out-of-roundness (ovality) and tolerances
The mean outside diameters of the pipe, d shall conform to Table 1.
em
For straight pipes, the maximum out-of-roundness shall conform to Table 1.
NOTE Care is taken that packaging and storage does not lead to an increased out of roundness and flattening
of the pipe. Additional information is given in EN 12007-2:2012, Annex A.
Table 1 — Mean outside diameters and out-of-roundness
Dimensions in millimetres
Nominal
Maximum out-of-
Nominal
outside Mean outside diameter
roundness for
size
diameter
b c
DN/OD straight pipes
a
d d
d
n em,min
em,max
16 16 16,0 16,3 1,2
20 20 20,0 20,3 1,2
25 25 25,0 25,3 1,2
32 32 32,0 32,3 1,3
40 40 40,0 40,4 1,4
50 50 50,0 50,4 1,4
63 63 63,0 63,4 1,5
75 75 75,0 75,5 1,6
90 90 90,0 90,6 1,8
110 110 110,0 110,7 2,2
125 125 125,0 125,8 2,5
140 140 140,0 140,9 2,8
160 160 160,0 161,0 3,2
180 180 180,0 181,1 3,6
200 200 200,0 201,2 4,0
225 225 225,0 226,4 4,5
250 250 250,0 251,5 5,0
280 280 280,0 281,7 9,8
315 315 315,0 316,9 11,1
355 355 355,0 357,2 12,5
400 400 400,0 402,4 14,0
450 450 450,0 452,7 15,6
500 500 500,0 503,0 17,5
560 560 560,0 563,4 19,6
630 630 630,0 633,8 22,1
710 710 710,0 716,4 24,9
800 800 800,0 807,2 28,0
a
In accordance with ISO 11922-1:2018, grade B for sizes ≤ 630 and grade A for sizes ≥ 710,
except for d 40 and 50.
n
b
Measurement of out-of-roundness shall be made at the point of manufacturing.
c
If other values for the out-of-roundness than those given in this table are necessary (e.g.
coiled pipes), they can be agreed between the manufacturer and the end-user.
7.3 Wall thicknesses and related tolerances
7.3.1 Minimum wall thicknesses
The use of any SDR derived from the pipe series S given according to ISO 4065 is permitted.
The minimum wall thickness, e , of pipes with SDR 17 and SDR 11 shall conform to Table 2.
min
Table 2 — Minimum wall thicknesses for pipes of SDR 17 and SDR 11
Dimensions in millimetres
b
Minimum wall thickness
Nominal size
a
e
min
DN/OD
SDR 17 SDR 11
c c
2,3 3,0
c c
2,3 3,0
c c
2,3 3,0
c
32 2,3 3,0
40 2,4 3,7
50 3,0 4,6
63 3,8 5,8
75 4,5 6,8
90 5,4 8,2
110 6,6 10,0
125 7,4 11,4
140 8,3 12,7
160 9,5 14,6
180 10,7 16,4
200 11,9 18,2
b
Minimum wall thickness
Nominal size
a
e
min
DN/OD
SDR 17 SDR 11
225 13,4 20,5
250 14,8 22,7
280 16,6 25,4
315 18,7 28,6
355 21,1 32,2
400 23,7 36,3
450 26,7 40,9
500 29,7 45,4
560 33,2 50,8
630 37,4 57,2
710 42,1 64,5
800 47,4 72,6
a
e = e
min n.
b
In some countries, the SDR 17,6 series is still specified.
c
The calculated values of e have been rounded up to 2,3 mm
min
for SDR 17 and 3,0 mm for SDR 11, re
...