ISO 21138-2:2020

INTERNATIONAL ISO
STANDARD 21138-2
Second edition
2020-01
Plastics piping systems for non-
pressure underground drainage and
sewerage — Structured-wall piping
systems of unplasticized poly(vinyl
chloride) (PVC-U), polypropylene (PP)
and polyethylene (PE) —
Part 2:
Pipes and fittings with smooth
external surface, Type A
Systèmes de canalisations en plastique pour les branchements et les
collecteurs d'assainissement sans pression enterrés — Systèmes de
canalisations à parois structurées en poly(chlorure de vinyle) non
plastifié (PVC-U), polypropylène (PP) et polyéthylène (PE) —
Partie 2: Tubes et raccords avec une surface externe lisse, type A
Reference number
©
ISO 2020
© ISO 2020
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Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 3
3.1 Terms and definitions . 3
3.2 Symbols . 4
3.3 Abbreviated terms . 4
4 Material . 5
4.1 General . 5
4.2 Unplasticized poly (vinyl chloride) (PVC-U) . 5
4.2.1 General. 5
4.2.2 Pipe and fitting material characteristics . 5
4.2.3 Utilization of non-virgin materials . 5
4.3 Polypropylene (PP) . 6
4.3.1 General. 6
4.3.2 Pipe and fitting material characteristics . 6
4.3.3 Melt mass-flow rate classification . 7
4.3.4 Utilization of non-virgin materials . 7
4.4 Polyethylene (PE) . 7
4.4.1 General. 7
4.4.2 Material characteristics of pipes and injection-moulded fittings . 7
4.4.3 Material characteristics of rotational-moulded fittings . 8
4.4.4 Utilization of non-virgin materials . 9
4.5 Sealing ring retaining components . . 9
4.6 Sealing rings . 9
4.7 Fused or welded joints . 9
4.8 Adhesives for PVC-U .10
5 Designation of wall construction and examples of typical jointing methods .10
5.1 Wall constructions designated as Type A .10
5.1.1 Multilayer construction or hollow-wall construction with axial hollow
sections, Type A1 constructions .10
5.1.2 Hollow-wall construction with spirally or radially formed hollow sections,
Type A2 constructions .10
5.1.3 Typical jointing methods for Type A structured-wall pipes .11
5.2 Designation and design of joints.11
6 General characteristics for pipes and fittings — Colour .11
7 Geometrical characteristics .12
7.1 General .12
7.2 Dimensions .12
7.2.1 Designation .12
7.2.2 Lengths of pipe .12
7.2.3 Diameters of Type A pipes and Type A spigots of pipes or fittings .12
7.2.4 Diameters and jointing dimensions of sockets and spigots.13
7.2.5 Wall thicknesses .14
7.3 Types of fitting.16
8 Physical characteristics .16
8.1 Unplasticized poly(vinyl chloride) (PVC-U) .16
8.1.1 Physical characteristics of PVC-U pipes .16
8.1.2 Physical characteristics of PVC-U fittings .17
8.2 Polypropylene (PP) .18
8.2.1 Physical characteristics of PP pipes .18
8.2.2 Physical characteristics of PP fittings .18
8.3 Polyethylene (PE) .19
8.3.1 Physical characteristics of PE pipes .19
8.3.2 Physical characteristics of PE fittings .19
9 Mechanical characteristics .20
9.1 Mechanical characteristics of pipes .20
9.1.1 General.20
9.1.2 Ring flexibility .21
9.1.3 Tensile strength of seams (Type A2) .21
9.1.4 Additional requirements .21
9.2 Mechanical characteristics of fittings .22
10 Performance requirements .22
11 Marking .24
11.1 General .24
11.2 Minimum required marking .24
11.2.1 Pipes .24
11.2.2 Fittings .24
Annex A (normative) Virgin PVC-U material .26
Annex B (normative) Utilization of non-virgin PVC-U material .27
Annex C (normative) Virgin PP material .30
Annex D (normative) Utilization of non-virgin PP material .31
Annex E (normative) Virgin PE material .34
Annex F (normative) Utilization of non-virgin PE material .35
Annex G (informative) Survey of possible use of reprocessed and recycled material .38
Bibliography .39
iv © ISO 2020 – 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 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 1, Plastics pipes and fittings for soil, waste and drainage (including
land drainage).
This second edition cancels and replaces the first edition (ISO 21138:2007), which has been technically
revised. The main changes compared to the previous edition are as follows:
— the normative references have been updated;
— references to EN test methods have been updated to ISO test methods, when applicable;
— editorial improvements have been made for clarification.
A list of all parts in the ISO 21138 series can be found on the ISO website.
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.
Introduction
The ISO 21138 series of standards covers plastics piping systems for non-pressure underground
drainage and sewerage, in particular thermoplastics structured-wall piping systems.
vi © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 21138-2:2020(E)
Plastics piping systems for non-pressure underground
drainage and sewerage — Structured-wall piping
systems of unplasticized poly(vinyl chloride) (PVC-U),
polypropylene (PP) and polyethylene (PE) —
Part 2:
Pipes and fittings with smooth external surface, Type A
1 Scope
This document, together with ISO 21138-1, specifies the definitions and requirements for pipes with
smooth external and internal surfaces (Type A), fittings and systems based on unplasticized poly(vinyl
chloride) (PVC-U), polypropylene (PP) and polyethylene (PE) structured-wall piping systems intended
to be used in non-pressure underground drainage and sewerage applications.
NOTE 1 Pipes, fittings and the system complying with this document can also be used for highway drainage
and surface water.
This document specifies test methods and test parameters.
This document covers a range of pipe and fitting sizes, materials, pipe constructions and nominal ring
stiffnesses, and gives recommendations concerning colours.
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 installation practices or codes.
In conjunction with ISO 21138-1, this document is applicable to structured-wall pipes and fittings, to
their joints and to joints with components of other plastics and non-plastics materials.
It is applicable to pipes and fittings with or without an integral socket with elastomeric ring seal joints
as well as welded and fused joints.
NOTE 3 For dimensions larger than DN/OD 1200, or DN/ID 1200, this document can serve as general guidance
regarding appearance, colour, physical and mechanical characteristics as well as performance requirements.
Test methods are not included in this document.
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 161-1, Thermoplastics pipes for the conveyance of fluids — Nominal outside diameters and nominal
pressures — Part 1: Metric series
ISO 178, Plastics — Determination of flexural properties
ISO 306:2013, Plastics — Thermoplastic materials — Determination of Vicat softening temperature (VST)
ISO 527-2:2012, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and
extrusion plastics
ISO 580, Plastics piping and ducting systems — Injection-moulded thermoplastics fittings — Methods for
visually assessing the effects of heating
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 1158, Plastics — Vinyl chloride homopolymers and copolymers — Determination of chlorine content
ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of
the resistance to internal pressure — Part 1: General method
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 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: Immersion
method, liquid pycnometer method and titration method
ISO 2505, Thermoplastics pipes — Longitudinal reversion — Test method and parameters
ISO 2507-1, Thermoplastics pipes and fittings — Vicat softening temperature — Part 1: General test
methodab
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 components — Determination of dimensions
ISO 3127, Thermoplastics pipes — Determination of resistance to external blows — Round-the-clock method
ISO 3451-1, Plastics — Determination of ash — Part 1: General methods
ISO 4435:2003, Plastics piping systems for non-pressure underground drainage and sewerage —
Unplasticized poly(vinyl chloride) (PVC-U)
ISO 6259-1, Thermoplastics pipes — Determination of tensile properties — Part 1: General test method
ISO 6259-2, Thermoplastics pipes — Determination of tensile properties — Part 2: Pipes made of
unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly (vinyl chloride) (PVC-C) and high-impact poly
(vinyl chloride) (PVC-HI)
ISO 8772:2006, Plastics piping systems for non-pressure underground drainage and sewerage —
Polyethylene (PE)
ISO 8773:2006, Plastics piping systems for non-pressure underground drainage and sewerage —
Polypropylene (PP)
ISO 9852, Unplasticized poly(vinyl chloride) (PVC-U) pipes — Dichloromethane resistance at specified
temperature (DCMT) — Test method
ISO 9967, Thermoplastics pipes — Determination of creep ratio
ISO 9969, Thermoplastics pipes — Determination of ring stiffness
ISO 11173, Thermoplastics pipes — Determination of resistance to external blows — Staircase method
ISO 11357-6, Plastics — Differential scanning calorimetry (DSC) — Part 6: Determination of oxidation
induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT)
ISO 13229, Thermoplastics piping systems for non-pressure applications — Unplasticized poly(vinyl
chloride) (PVC-U) pipes and fittings — Determination of the viscosity number and K-value
ISO 13254, Thermoplastics piping systems for non-pressure applications — Test method for watertightness
2 © ISO 2020 – All rights reserved

ISO 13259:2018, Thermoplastics piping systems for underground non-pressure applications — Test method
for leaktightness of elastomeric sealing ring type joints
ISO 13260:2010, Thermoplastics piping systems for non-pressure underground drainage and sewerage —
Test method for resistance to combined temperature cycling and external loading
ISO 13262, Thermoplastics piping systems for non-pressure underground drainage and sewerage —
Thermoplastics spirally-formed structured-wall pipes — Determination of the tensile strength of a seam
ISO 13265, Thermoplastics piping systems for non-pressure underground drainage and sewerage — Joints
for buried non-pressure applications — Test method for the long-term sealing performance of joints with
elastomeric seals by estimating the sealing pressure
ISO 13968, Plastics piping and ducting systems — Thermoplastics pipes — Determination of ring flexibility
ISO 18373-1, Rigid PVC pipes — Differential scanning calorimetry (DSC) method — Part 1: Measurement of
the processing temperature
ISO 21138-1, Plastics piping systems for non-pressure underground drainage and sewerage — Structured-
wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene
(PE) — Part 1: Material specifications and performance criteria for pipes, fittings and the system
ISO 21138-3, Plastics piping systems for non-pressure underground drainage and sewerage — Structured-
wall piping systems of unplasticized poly(vinyl chloride) (PVC-U), polypropylene (PP) and polyethylene
(PE) — Part 3: Pipes and fittings with a non-smooth external surface, Type B
ISO 22088-3, Plastics — Determination of resistance to environmental stress cracking (ESC) — Part 3:
Bent strip method
EN 681-1, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 1: Vulcanized rubber
EN 681-2, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 2: Thermoplastic elastomers
EN 681-4, Elastomeric seals — Materials requirements for pipe joint seals used in water and drainage
applications — Part 4: Cast polyurethane sealing elements
EN 10204:2004, Metallic products — Types of inspection documents
EN 12099, Plastics piping systems — Polyethylene piping materials and components — Determination of
volatile content
EN 15344, Plastics — Recycled plastics — Characterisation of polyethylene) (PE) recyclates
EN 15345, Plastics — Recycled plastics — Characterisation of polypropylene) (PP) recyclates
EN 15346:2014, Plastics — Recycled plastics — Characterisation of poly(vinyl chloride) (PVC) recyclates
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21138-1 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
3.2 Symbols
A length of engagement, or maximum pull-out whilst maintaining tightness
A minimum value of A
min
C depth of sealing zone
C maximum value of C
max
D inside diameter of a socket
i
D minimum mean inside diameter of a socket
im, min
d outside diameter (of a pipe or a spigot)
e
d maximum value of the mean d
em, max e
d minimum value of the mean d
em, min e
d inside diameter of a pipe
i
d maximum value of the mean d
im, max i
d minimum value of the mean d
im, min i
e wall thickness (at any point)
e construction height
c
e wall thickness of the socket
e wall thickness of the groove
e wall thickness of the inside layer (waterway wall thickness)
e wall thickness of the inside layer under a hollow section
l effective length of a pipe
3.3 Abbreviated terms
CaCO calcium carbonate
CT close tolerance
DSC differential scanning calorimetry
MgCO magnesium carbonate
MFR melt mass-flow rate
OIT oxidation induction time
TIR true impact rate
TPE thermoplastic elastomer
VST Vicat softening temperature
4 © ISO 2020 – All rights reserved

4 Material
4.1 General
The material shall be one of the following: unplasticized poly (vinyl chloride) (PVC-U), polypropylene
(PP) or polyethylene (PE) to which are added those additives that are needed to facilitate the
manufacture of components conforming to this document, including the relevant annexes.
4.2 Unplasticized poly (vinyl chloride) (PVC-U)
4.2.1 General
The raw material shall be PVC-U to which are added those additives that are needed to facilitate the
manufacture of components conforming to the requirements of this document (see also Annex A).
NOTE Additional information on the characteristics of PVC-U material or components made thereof is given
in ISO 21138-1:2020, Annex A.
4.2.2 Pipe and fitting material characteristics
When tested in accordance with the test method specified in Table 1, using the indicated parameters,
the material shall have characteristics conforming to the requirements given in Table 1.
Table 1 — Material characteristics of PVC-U pipes and injection-moulded fittings
Characteristic Requirements Test parameters Test
method
Resistance to internal No failure during Test temperature 60 °C ISO 1167-1
a,b,c
pressure the test period
Circumferential stress  ISO 1167-2
—  pipe material 10 MPa
—  fitting material 6,3 MPa
Test period 1 000 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
a
For extrusion compounds, this test shall be carried out in the form of a solid-wall pipe made from the relevant extrusion
material.
b
For injection-moulding compounds, this test shall be carried out in the form of an injection-moulded or extruded
sample in solid-wall pipe form made from the relevant material.
c
Not required for the intermediate layer of Type A1 pipes.
4.2.3 Utilization of non-virgin materials
For the utilization of non-virgin PVC-U materials, conditions and requirements are given in Annex B,
and the non-virgin materials shall conform to the characterization specified in EN 15346.
NOTE Annex G gives a survey of the possible uses of reprocessed and recycled materials.
4.3 Polypropylene (PP)
4.3.1 General
The base material shall be polypropylene (PP) to which are added those additives that are needed to
facilitate the manufacture of components conforming to the requirements of this document (see also
Annex C).
NOTE Additional information on the characteristics of PP material or components made thereof is given in
ISO 21138-1:2020, Annex A.
4.3.2 Pipe and fitting material characteristics
When tested in accordance with the test methods specified in Table 2, using the indicated parameters,
the material shall have characteristics conforming to the requirements given in Table 2.
Table 2 — Material characteristics of PP pipes and injection-moulded fittings
Characteristic Requirements Test parameters Test
method
Resistance to internal No failure during Test temperature 80 °C ISO 1167-1
a,b,c
pressure 140 h the test period
Circumferential stress 4,2 MPa ISO 1167-2
Test period 140 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Resistance to internal No failure during Test temperature 95 °C ISO 1167-1
a,b,c
pressure 1 000 h the test period
Circumferential stress 2,5 MPa ISO 1167-2
Test period 1 000 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Melt mass-flow rate ≤1,5 g/10 min Temperature 230 °C ISO 1133-1
(MFR)
Loading mass 2,16 kg
Thermal stability, ≥8 min Temperature 200 °C ISO 11357-6
(OIT)
a
For extrusion compounds, this test shall be carried out in the form of a solid-wall pipe made from the relevant extrusion
material.
b
For injection-moulding compounds, this test shall be carried out in the form of an injection-moulded or extruded
sample in solid-wall pipe form made from the relevant material.
c
Not required for the intermediate layer of Type A1 pipes.
6 © ISO 2020 – All rights reserved

4.3.3 Melt mass-flow rate classification
Materials for pipes and fittings intended for jointing in the field by fusion or welding shall be designated
by the following MFR classes:
— Class A:  MFR ≤ 0,3 g/10 min;
— Class B:  0,3 g/10 min < MFR ≤ 0,6 g/10 min;
— Class C:  0,6 g/10 min < MFR ≤ 0,9 g/10 min;
— Class D:  0,9 g/10 min < MFR ≤ 1,5 g/10 min.
In the case where a raw material, because of its MFR tolerance, arbitrarily falls in one of two adjacent
classes, the manufacturer of the components may mark the MFR class on the product as follows:
— for an MFR value across the border between A and B it is permitted to classify as class A;
— for an MFR value across the border between B and C it is permitted to classify as class C;
— for an MFR value across the border between C and D it is permitted to classify as class D.
4.3.4 Utilization of non-virgin materials
For the utilization of non-virgin PP materials, conditions and requirements are given in Annex D, and
the non-virgin materials shall conform to the characterization specified in EN 15345.
NOTE Annex G gives a survey of the possible uses of reprocessed and recycled materials.
4.4 Polyethylene (PE)
4.4.1 General
The base material shall be polyethylene (PE) to which are added those additives that are needed to
facilitate the manufacture of components conforming to this document. See also Annex E.
NOTE Additional information on the characteristics of PE material or components made thereof is given in
ISO 21138-1:2020, Annex A.
4.4.2 Material characteristics of pipes and injection-moulded fittings
When tested in accordance with the test method specified in Table 3, using the indicated parameters,
the material shall have characteristics conforming to the requirements given in Table 3.
Table 3 — Material characteristics of PE pipes and injection-moulded fittings
Characteristic Requirements Test parameters Test
method
Resistance to internal No failure during Test temperature 80 °C ISO 1167-1
a,b,c
pressure 165 h the test period
Circumferential stress 4,0 MPa ISO 1167-2
Test period 165 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Resistance to internal No failure during Test temperature 80 °C ISO 1167-1
a,b,c
pressure 1 000 h the test period
Circumferential stress 2,8 MPa ISO 1167-2
Test period 1 000 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Melt mass-flow rate ≤1,6 g/10 min Temperature 190 °C ISO 1133-1
(MFR)
Loading mass 5 kg
Thermal stability ≥20 min Temperature 200 °C ISO 11357-6
(OIT)
d 3
Reference density ≥930 kg/m ISO 1183-1 ISO 1183-1
a
For extrusion compounds, this test shall be carried out in the form of a solid-wall pipe made from the relevant extrusion
material.
b
For injection-moulding compounds, this test shall be carried out in the form of an injection-moulded or extruded
sample in solid-wall pipe form made from the relevant material.
c
Not required for the intermediate layer of Type A1 pipes.
d
To be measured on the base polymer.
4.4.3 Material characteristics of rotational-moulded fittings
When tested in accordance with the test methods specified in Table 4, using the indicated parameters,
the material shall have characteristics conforming to the requirements given in Table 4.
8 © ISO 2020 – All rights reserved

Table 4 — Material characteristics of PE rotational-moulded fittings
Characteristic Requirements Test parameters Test
method
Resistance to internal No failure during Test temperature 60 °C ISO 1167-1
a
pressure 165 h the test period
Circumferential stress 3,9 MPa ISO 1167-2
Test period 165 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Resistance to internal No failure during Test temperature 60 °C ISO 1167-1
a
pressure 1 000 h the test period
Circumferential stress 3,2 MPa ISO 1167-2
Test period 1 000 h
Type of test Water-in-water
End caps Type A or B
Orientation Free
Number of test pieces 3
Conditioning period In accordance with
ISO 1167-1
Melt mass-flow rate 3 g/10 min ≤ MFR Temperature 190 °C ISO 1133-1
(MFR) ≤16 g/10 min
Loading mass 5 kg
Thermal stability, ≥10 min Temperature 200 °C ISO 11357-6
(OIT)
b 3
Reference density ≥925 kg/m Temperature (23 ± 2) °C ISO 1183-1
a
This test shall be carried out in the form of an injection-moulded or extruded sample in solid-wall pipe form made from
the relevant material.
b
To be measured on the base polymer.
4.4.4 Utilization of non-virgin materials
For the utilization of non-virgin PE materials, conditions and requirements are given in Annex F, and
the non-virgin materials shall conform to the characterization specified in EN 15344.
NOTE Annex G gives a survey of the possible uses of reprocessed and recycled materials.
4.5 Sealing ring retaining components
It is permitted that sealing rings be retained using components made from any polymer.
4.6 Sealing rings
The sealing ring material shall conform to EN 681-1, EN 681-2 or EN 681-4, as applicable.
The sealing ring shall have no detrimental effects on the properties of the components and shall not
cause the test assembly to fail the performance requirements given in Clause 10.
4.7 Fused or welded joints
The design of fused or welded joints together with the manufacturer's instructions for the jointing
process shall not cause the test assembly to fail the performance requirements given in Clause 10.
4.8 Adhesives for PVC-U
The adhesive for solvent cement jointing of PVC-U shall be solvent cement and shall be as specified by
the manufacturer of the pipes or fittings, where appropriate.
The adhesive shall have no detrimental effects on the properties of components and shall not cause the
test assembly to fail the performance requirements given in Clause 10.
5 Designation of wall construction and examples of typical jointing methods
NOTE The figures are schematic sketches only to indicate the relevant dimensions. They do not necessarily
represent the manufactured components.
5.1 Wall constructions designated as Type A
5.1.1 Multilayer construction or hollow-wall construction with axial hollow sections, Type A1
constructions
A pipe or fitting with smooth inside and outside surfaces and in which the outer and inner walls are
connected by internal axial ribs or a foamed or non-foamed intermediate layer of thermoplastics shall
be designated Type A1. Typical examples of Type A1 constructions are shown in Figure 1.
Figure 1 — Typical examples of wall construction Type A1
5.1.2 Hollow-wall construction with spirally or radially formed hollow sections, Type A2
constructions
A pipe or fitting with smooth inside and outside surfaces and in which the outer and inner walls are
connected by internal spirally or radially formed ribs shall be designated Type A2. A typical example of
Type A2 constructions is shown in Figure 2.
10 © ISO 2020 – All rights reserved

Figure 2 — Typical example of wall construction Type A2
5.1.3 Typical jointing methods for Type A structured-wall pipes
Relevant dimensions for typical joints of Type A pipes are shown in Figure 3. When factory-mounted
sealing rings are used, the dimensions A and C may be defined relative to the effective sealing point.
Figure 3 — Typical examples of joints for Type A constructions
5.2 Designation and design of joints
Pipes and fittings may be designed with spigot ends and sockets of another construction than the pipe
or fitting body. Such constructions may be Type A1, Type A2 or Type B or solid wall. For definitions and
specifications for Type B, see ISO 21138-3.
NOTE Joints with elastomeric sealing rings are designed either with the sealing ring positioned on the spigot
or in the socket. See Figure 3.
6 General characteristics for pipes and fittings — Colour
Colour and appearance are specified in ISO 21138-1.
7 Geometrical characteristics
7.1 General
All dimensions shall be measured in accordance with ISO 3126.
7.2 Dimensions
7.2.1 Designation
Pipes and fittings are sized according to their outside diameter (DN/OD series) and/or according to
their inside diameter (DN/ID series).
7.2.2 Lengths of pipe
The effective length of pipe, l, shall be not less than that specified by the manufacturer when measured
as shown in Figure 3.
7.2.3 Diameters of Type A pipes and Type A spigots of pipes or fittings
The outside diameters and the tolerances of Type A pipes and plain spigots for DN/OD series of pipes
and fittings intended to have jointing dimensions conforming to ISO 4435, ISO 8772 or ISO 8773 for
PVC, PE or PP respectively, shall conform to Table 5.
The nominal sizes and minimum mean inside diameters are specified in Table 9.
Dimensions lower than DN/ID 100 and DN/OD 110 are not permitted.
Other dimensions greater than DN/OD 110 and not included in Table 5 are permitted and shall be
selected from ISO 161-1. The minimum inside diameter, d , shall be linearly interpolated between
im,min
the adjacent values specified in Table 9.
Table 5 — Mean outside diameters and tolerances
Dimensions in millimetres
Nominal size Mean outside diameter
a
Close tolerances (CT) Enlarged tolerances
DN/OD d d d
em,min em,max em,max
110 110,0 110,3 111,0
125 125,0 125,3 126,2
160 160,0 160,4 161,5
200 200,0 200,5 201,8
250 250,0 250,5 252,3
315 315,0 315,6 317,9
400 400,0 400,7 403,6
500 500,0 500,9 504,5
630 630,0 631,1 635,7
800 800,0 801,3 807,2
1 000 1 000,0 1 001,6 1 009,0
1 200 1 200,0 1 202,0 1 210,0
a
Enlarged tolerances are permitted for PP for DN/OD ≥ 200 and for DN/OD ≥ 110 for PE.
12 © ISO 2020 – All rights reserved

7.2.4 Diameters and jointing dimensions of sockets and spigots
Diameters and jointing dimensions of sockets and spigots shall conform to Table 6, Table 7 and Table 8
as appropriate.
Table 6 — Diameters and lengths of elastomeric ring seal sockets and spigots of PVC-U pipes
and fittings
Dimensions in millimetres
Nominal
Nominal
outside Socket Spigot
size
diameter
DN/OD d D A C L
n im,min min max 1,min
110 110,0 110,4 32 26 60
125 125,0 125,4 35 26 67
160 160,0 160,6 42 32 81
200 200,0 200,6 50 40 99
250 250,0 250,8 55 70 125
315 315,0 316,0 62 70 132
400 400,0 401,2 70 80 150
a
500 500,0 501,5 80 80 160
a
630 630,0 631,9 93 95 188
a
800 800,0 802,4 110 110 220
a
1 000 1 000,0 1 003,0 130 140 270
1 200 1 200,0 — 150 — —
a
Higher values for C are allowed, provided the manufacturer states in his documentation the actual value of L
1,min
required by the formula L = A + C.
1,min min
Other dimensions are permitted and shall be selected from ISO 161-1.
Table 7 — Diameters and lengths of elastomeric ring seal sockets and spigots of PP pipes
and fittings
Dimensions in millimetres
Nominal
Nominal
outside Socket Spigot
size
diameter
a b
DN/OD d D A C L
n im,min min max 1,min
110 110,0 110,4 40 22 62
125 125,0 125,4 43 26 68
160 160,0 160,5 50 32 82
200 200,0 200,6 58 40 98
250 250,0 252,4 68 50 118
315 315,0 318,0 81 63 144
400 400,0 403,7 98 80 178
500 500,0 5
...