SIST EN 12666-1:2026
(Main)Plastics piping systems for non-pressure underground drains and sewers - Polyethylene (PE) - Part 1: Specifications for pipes, fittings and the system
- Abstract
This document specifies definitions and requirements for solid-wall pipes with or without internal skin and smooth internal and external surfaces extruded from the same compound throughout the wall, fittings and the system of polyethylene (PE) piping systems to be intended for use in non-pressure underground drains and sewers for wastewater.
NOTE 1 Products complying with this document can also be used in non-pressure underground drains and sewers for surface water.
This document is applicable to:
a) non-pressure drains and sewers, which are intended to be used buried underground outside the building structure, reflected in the marking of products by “U”;
b) non-pressure drains and sewers, which are intended to be used buried underground both outside (application area code “U”) and within the building structure, reflected in the marking of products by “UD”.
This document specifies test methods referred to in this document and test parameters.
This document is applicable to pipes and fittings with or without an integral socket.
This document covers a range of pipe and fitting sizes, stiffness classes, tolerance classes 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 any relevant national regulations and installation practices or codes.
In conjunction with CEN/TS 12666-2 [1] it is applicable to PE pipes and fittings, their joints and to joints with components of other plastics and non-plastics materials intended to be used for buried piping systems for non-pressure drains and sewers.
The fittings can be manufactured by injection moulding or can be fabricated from pipes and/or mouldings.
This document is applicable to PE pipes and fittings for the following types of joints:
— elastomeric ring seal joints;
— butt fused joints;
— electrofusion joints;
— mechanical joints.
NOTE 3 Pipes, fittings and other components conforming to any of the plastics product standards listed in the Annex C (informative) can be used with pipes and fittings conforming to this document, provided they conform to the requirements for joint dimensions given in Clause 7 and to the requirements of Clause 7 and Table 13.
- Status
- Published
- Public Enquiry End Date
- 25-Jun-2025
- Publication Date
- 15-Jun-2026
- Technical Committee
- PCV - Plastic pipes, fittings and valves
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 10-Jun-2026
- Due Date
- 15-Aug-2026
- Completion Date
- 16-Jun-2026
SIST EN 12666-1:2026 is the Slovenian national standard identical to EN 12666-1:2026, published by CEN. It specifies the definitions, material requirements, dimensions, test methods, performance requirements and marking for polyethylene (PE) pipes, fittings and systems used in non-pressure underground drains and sewers for wastewater. It is aimed at manufacturers, specifiers, purchasers and test laboratories that need to select, make, verify or buy buried PE drainage components.
What does SIST EN 12666-1:2026 specify?
SIST EN 12666-1:2026 sets requirements for solid-wall PE pipes, fittings and the system for buried, non-pressure underground drains and sewers. It also covers the test methods and test parameters used to check those requirements, so the document is useful both for product design and for conformity testing.
The scope includes products for underground use outside the building structure, marked U, and products intended for use both outside and within the building structure, marked UD. It applies to pipes and fittings with or without an integral socket, and to the joint types listed in the document.
| Annex | What it covers |
|---|---|
| Annex A | Utilization of PE recyclates |
| Annex B | General characteristics of PE pipes and fittings |
| Annex C | Product standards of components that can be connected to components conforming to this document |
The document is organized into clauses on scope, normative references, terms and definitions, symbols and abbreviations, material, appearance and colour, geometry, mechanical characteristics, physical characteristics, performance requirements, sealing rings and marking.
What are the key requirements of SIST EN 12666-1:2026?
Clause 5 requires the pipe and fitting compound to be based on PE, with additives allowed when needed to meet the document. SIST EN 12666-1:2026 permits virgin material, reworked material and recyclates, but recyclates must meet Annex A. In practice, the manufacturer has to control the composition of the compound and keep evidence that the selected recyclate level still meets the standard.
Clause 5 also ties conformity to the compound tests listed in Table 1. Those tests cover pressure resistance, melt flow and thermal stability for the compound used in pipes and injection-moulded fittings. For a buyer or quality manager, this means material qualification is not only about appearance - it is verified by defined laboratory methods.
Clause 6 requires smooth, clean internal and external surfaces, cleanly cut pipe ends and square end faces. Colours are to be through the wall, with black preferred or another colour agreed by the manufacturer and purchaser. A co-extruded inner skin may have a different colour if its material also complies with Clause 5. In practice, this helps with visual acceptance and product identification.
Clause 7 controls geometry. SIST EN 12666-1:2026 uses EN ISO 3126 for measurement and then sets dimensions for pipe outside diameter, length, wall thickness, fitting bodies, sockets and spigots. It also allows close-tolerance spigot ends for certain fittings and gives fitting types such as bends, couplers, reducers, branches, plugs and push-fit sockets. This matters because joints only work reliably when the pipe and fitting dimensions match the intended connection method.
Clause 8 links stiffness to use in the ground. Pipes are classified by ring stiffness class, and fittings are classified so their geometry gives stiffness at least comparable to matching pipe sizes. Additional tests cover flexibility or mechanical strength for certain fabricated fittings and impact strength for relevant fabricated parts. In practice, this is the part that tells you whether the selected pipe and fitting combination is suitable for burial loads and handling.
Clause 9 checks physical behaviour after processing and heating. Pipes are tested for longitudinal reversion and for melt mass-flow rate change after conversion into pipe. Fittings are checked for effects of heating, and fabricated fittings are also checked for watertightness. This helps confirm that the manufacturing process has not weakened the component.
Clause 10 checks system performance. Joints and assemblies are tested for tightness under deflection and pressure, and certain components intended for UD use are also tested for elevated temperature cycling. Butt-fused joints are treated separately from the elastomeric ring seal and electrofusion joint checks. This is the part that matters most for installation and service reliability, because it shows whether the joint stays leak-tight when the buried system moves or is loaded.
Clause 11 requires sealing rings to conform to EN 681-1 or EN 681-2, as applicable, and to avoid harmful effects on the pipe or fitting. Clause 12 sets the marking information for pipes and fittings, including the standard reference, application area code, manufacturer identification, nominal size, wall thickness or SDR, material, stiffness class and traceability information. For procurement and quality control, the marking is what links the installed product back to its declared specification.
What terms does SIST EN 12666-1:2026 define?
- Drain - a pipeline, usually underground, that carries wastewater from a source to a sewer.
- Sewer - a pipeline or other construction, usually underground, that carries wastewater from more than one source.
- Wastewater - water made up of domestic, industrial or commercial discharge, surface run-off and possible sewer infiltration water.
- Application area code - the marking code that shows whether a product is intended for U use or for UD use.
- DN/OD - nominal size related to the outside diameter of a component.
- SDR - standard dimension ratio, used to describe pipe series by the relationship between outside diameter and wall thickness.
- SN - nominal ring stiffness class, which indicates the minimum required ring stiffness of the pipe or stiffness of the fitting.
- Recyclate - plastics material resulting from recycling pre-consumer or post-consumer plastics products.
Who uses SIST EN 12666-1:2026?
SIST EN 12666-1:2026 is used by PE pipe and fitting manufacturers, because it defines the materials, dimensions, tests and marking they have to meet. It is also used by recyclate suppliers and manufacturers who want to include recyclates under Annex A.
Specifiers, purchasers and quality managers use SIST EN 12666-1:2026 to choose suitable U or UD products and to check that declared sizes, stiffness classes, joints and marking match the project requirements. Testing and certification bodies use it to verify conformity by the listed test methods. Designers working on buried non-pressure drainage and sewerage systems use it together with the related guidance documents named by CEN.
What changed in SIST EN 12666-1:2026 from the previous edition?
Compared with EN 12666-1:2005+A1:2011, this edition:
- changes the title
- follows a new template
- adds definitions for wastewater and surface water
- updates material definitions in line with EN 14541-1:2022
- rewrites Clause 5 on material
- adds Annex A on the utilization of PE recyclates
- changes the maximum marking interval in Clause 12.2
It also supersedes EN 12666-1:2005+A1:2011.
Which standards are used with SIST EN 12666-1:2026?
| Standard | What it contributes |
|---|---|
| EN 681-1 / EN 681-2 | Material requirements for elastomeric seals used in water and drainage applications |
| EN 12099 | Volatile content determination for PE piping materials and components |
| EN 15346:2024 | Characterization of PVC recyclates, used in recyclate-related characterization work |
| EN ISO 472:2013 | Plastic vocabulary used for terms and definitions |
| EN ISO 1043-1 | Symbols and abbreviated terms for plastics |
| EN ISO 527-2 | Tensile test conditions for moulding and extrusion plastics |
| EN ISO 580 | Visual assessment of heating effects on injection-moulded thermoplastics fittings |
| EN ISO 1133-1 | Melt mass-flow rate and melt volume-flow rate test method |
| EN ISO 1167-1 / EN ISO 1167-2 | Internal pressure test method and preparation of pipe test pieces |
| EN ISO 1183-1 / EN ISO 1183-2 | Density determination methods |
| EN ISO 2505 | Longitudinal reversion test method for thermoplastics pipes |
| EN ISO 3126 | Measurement of plastics component dimensions |
| EN ISO 3451-1 | Ash determination for plastics |
| EN ISO 9969:2016 | Ring stiffness test for thermoplastics pipes |
| EN ISO 11357-6 | Oxidation induction time and temperature by DSC |
| EN ISO 13254 | Watertightness test for non-pressure applications |
| EN ISO 13257:2018 | Resistance to elevated temperature cycling |
| EN ISO 13259 | Leaktightness of elastomeric sealing ring joints |
| EN ISO 13263 | Impact strength of thermoplastics fittings |
| EN ISO 13264 | Mechanical strength or flexibility of fabricated fittings |
| CEN/TS 12666-2 | Guidance for assessment of conformity for the same PE system |
| CEN/TS 1046 | Trench installation guidance |
| CEN/TS 15223:2025 | Structural design guidance for buried thermoplastics piping systems |
| EN 14541-1:2022 | Vocabulary for utilization of thermoplastics recyclates |
| EN 16323:2014 | Glossary source for wastewater engineering terms |
| EN 1401-1 | Reference for compatible PVC-U drainage components and close-tolerance connection details |
| ISO 4065:2018 | Universal wall thickness table for thermoplastics pipes |
| ISO 265-1 | Basic dimensions for fittings used as a design guide |
| ISO 9624 | Mating dimensions for flange adapters and loose backing flanges |
| EN 476 | General requirements for components used in drains and sewers |
| ISO 13967 | Ring stiffness of thermoplastics fittings |
| ISO/TR 10358 / ISO/TR 7620 | Chemical resistance guidance for PE and rubber materials |
| CEN/TS 16010 / CEN/TS 16011 | Sampling and sample preparation guidance for recyclates |
| CEN/TS 14541-2:2022 | Recommendations for relevant recyclate characteristics |
What does the SIST EN 12666-1:2026 document contain?
SIST EN 12666-1:2026 contains tables for compound characteristics, pipe dimensions, wall thicknesses, socket and spigot dimensions, electrofusion socket dimensions, stiffness and test conditions, physical characteristics, performance requirements and marking. It also includes figures that show how lengths and socket or spigot dimensions are measured, and figures for bends, couplers, reducers, branches, plugs and push-fit sockets.
Annex A gives the framework for using PE recyclates, including the agreed specification, the required declaration and the characteristics that should be covered. Annex B summarizes general PE properties such as density, creep ratio, chemical resistance, abrasion resistance, hydraulic roughness and expected diametric deflection. Annex C lists component standards that can be connected to components conforming to this document when the joint dimensions are compatible.
For design, testing and product qualification, the document gives the geometry, test set-ups and marking rules needed to verify that the pipe, fitting and joint system is suitable for buried non-pressure drainage and sewerage use.
Relations
- Effective Date
- 02-Sep-2026
- Effective Date
- 24-Jun-2026
- Effective Date
- 10-Jun-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Referred By
SIST EN 1366-3:2009 - Fire resistance tests for service installations - Part 3: Penetration seals - Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
- Effective Date
- 27-May-2026
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Frequently Asked Questions
SIST EN 12666-1:2026 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Plastics piping systems for non-pressure underground drains and sewers - Polyethylene (PE) - Part 1: Specifications for pipes, fittings and the system". This standard covers: This document specifies definitions and requirements for solid-wall pipes with or without internal skin and smooth internal and external surfaces extruded from the same compound throughout the wall, fittings and the system of polyethylene (PE) piping systems to be intended for use in non-pressure underground drains and sewers for wastewater. NOTE 1 Products complying with this document can also be used in non-pressure underground drains and sewers for surface water. This document is applicable to: a) non-pressure drains and sewers, which are intended to be used buried underground outside the building structure, reflected in the marking of products by “U”; b) non-pressure drains and sewers, which are intended to be used buried underground both outside (application area code “U”) and within the building structure, reflected in the marking of products by “UD”. This document specifies test methods referred to in this document and test parameters. This document is applicable to pipes and fittings with or without an integral socket. This document covers a range of pipe and fitting sizes, stiffness classes, tolerance classes 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 any relevant national regulations and installation practices or codes. In conjunction with CEN/TS 12666-2 [1] it is applicable to PE pipes and fittings, their joints and to joints with components of other plastics and non-plastics materials intended to be used for buried piping systems for non-pressure drains and sewers. The fittings can be manufactured by injection moulding or can be fabricated from pipes and/or mouldings. This document is applicable to PE pipes and fittings for the following types of joints: — elastomeric ring seal joints; — butt fused joints; — electrofusion joints; — mechanical joints. NOTE 3 Pipes, fittings and other components conforming to any of the plastics product standards listed in the Annex C (informative) can be used with pipes and fittings conforming to this document, provided they conform to the requirements for joint dimensions given in Clause 7 and to the requirements of Clause 7 and Table 13.
This document specifies definitions and requirements for solid-wall pipes with or without internal skin and smooth internal and external surfaces extruded from the same compound throughout the wall, fittings and the system of polyethylene (PE) piping systems to be intended for use in non-pressure underground drains and sewers for wastewater. NOTE 1 Products complying with this document can also be used in non-pressure underground drains and sewers for surface water. This document is applicable to: a) non-pressure drains and sewers, which are intended to be used buried underground outside the building structure, reflected in the marking of products by “U”; b) non-pressure drains and sewers, which are intended to be used buried underground both outside (application area code “U”) and within the building structure, reflected in the marking of products by “UD”. This document specifies test methods referred to in this document and test parameters. This document is applicable to pipes and fittings with or without an integral socket. This document covers a range of pipe and fitting sizes, stiffness classes, tolerance classes 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 any relevant national regulations and installation practices or codes. In conjunction with CEN/TS 12666-2 [1] it is applicable to PE pipes and fittings, their joints and to joints with components of other plastics and non-plastics materials intended to be used for buried piping systems for non-pressure drains and sewers. The fittings can be manufactured by injection moulding or can be fabricated from pipes and/or mouldings. This document is applicable to PE pipes and fittings for the following types of joints: — elastomeric ring seal joints; — butt fused joints; — electrofusion joints; — mechanical joints. NOTE 3 Pipes, fittings and other components conforming to any of the plastics product standards listed in the Annex C (informative) can be used with pipes and fittings conforming to this document, provided they conform to the requirements for joint dimensions given in Clause 7 and to the requirements of Clause 7 and Table 13.
SIST EN 12666-1:2026 is classified under the following ICS (International Classification for Standards) categories: 23.040.01 - Pipeline components and pipelines in general; 23.040.05 - Pipeline and its parts for external sewage systems; 91.140.80 - Drainage systems; 93.030 - External sewage systems. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 12666-1:2026 has the following relationships with other standards: It is inter standard links to SIST EN 681-1:2000, SIST EN ISO 472:2014, SIST EN ISO 3451-1:2026, SIST EN 13476-2:2018+A1:2020, SIST EN 13476-2:2007, SIST EN 1366-3:2009, SIST EN 1366-3:2022+A1:2025, SIST EN 13476-2:2025, SIST EN 13476-3:2018+A1:2020, SIST EN 13598-2:2020, SIST EN 13476-3:2025, SIST EN 13598-2:2009, SIST EN 13598-2:2016, SIST EN 13476-3:2007+A1:2009, SIST EN ISO 11300-1:2026. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 12666-1:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2026
Cevni sistemi iz polimernih materialov za odpadno vodo in kanalizacijo, ki delujejo
po težnostnem principu in so položeni v zemljo - Polietilen (PE) - 1. del:
Specifikacije za cevi, fitinge in sistem
Plastics piping systems for non-pressure underground drains and sewers - Polyethylene
(PE) - Part 1: Specifications for pipes, fittings and the system
Kunststoff-Rohrleitungssysteme für erdverlegte Abwasserkanäle und -leitungen -
Polyethylen (PE) - Teil 1: Anforderungen an Rohre, Formstücke und das
Rohrleitungssystem
Systèmes de canalisations en plastique pour les branchements et les collecteurs
d’assainissement enterrés sans pression - Polyéthylène (PE) - Partie 1 : Spécifications
pour les tubes, les raccords et le système
Ta slovenski standard je istoveten z: EN 12666-1:2026
ICS:
23.040.05 Cevovodi za zunanje Pipeline and its parts for
sisteme za odpadno vodo in external sewage systems
njihovi deli
91.140.80 Drenažni sistemi Drainage systems
93.030 Zunanji sistemi za odpadno External sewage systems
vodo
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 12666-1
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2026
EUROPÄISCHE NORM
ICS 93.030 Supersedes EN 12666-1:2005+A1:2011
English Version
Plastics piping systems for non-pressure underground
drains and sewers - Polyethylene (PE) - Part 1:
Specifications for pipes, fittings and the system
Systèmes de canalisations en plastique pour les Kunststoff-Rohrleitungssysteme für erdverlegte
branchements et les collecteurs d'assainissement Abwasserkanäle und -leitungen - Polyethylen (PE) -
enterrés sans pression - Polyéthylène (PE) - Partie 1 : Teil 1: Anforderungen an Rohre, Formstücke und das
Spécifications pour les tubes, les raccords et le système Rohrleitungssystem
This European Standard was approved by CEN on 20 April 2026.
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, Türkiye 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12666-1:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols and abbreviations . 12
4.1 Symbols . 12
4.2 Abbreviations . 12
5 Material . 12
5.1 General. 12
5.2 Compound characteristics of pipe and injection moulded fittings . 13
5.3 Sealing ring retaining components . 14
5.4 Fused or welded joints . 14
6 Appearance and colour . 14
6.1 Appearance . 14
6.2 Colour . 14
7 Geometrical characteristics . 14
7.1 General. 14
7.2 Dimensions of pipes . 15
7.2.1 Outside diameter . 15
7.2.2 Length of pipes . 15
7.2.3 Wall thickness . 16
7.3 Dimensions of fittings . 17
7.3.1 Outside diameter for spigots . 17
7.3.2 Outside diameter for spigots with close tolerances (Type CT) . 17
7.3.3 Design lengths . 18
7.3.4 Wall thicknesses of the body of a fitting . 18
7.4 Dimensions of sockets and spigots . 19
7.4.1 Elastomeric ring seal sockets and spigots . 19
7.4.2 Butt fusion spigot ends . 22
7.4.3 Electrofusion sockets . 22
7.4.4 Flange joints . 23
7.5 Types of fittings . 24
8 Mechanical characteristics . 27
8.1 Mechanical characteristics of pipes . 27
8.2 Mechanical characteristics of fittings . 27
8.2.1 Ring stiffness class . 27
8.2.2 Additional requirements. 28
9 Physical characteristics . 28
9.1 Physical characteristics of pipes . 28
9.2 Physical characteristics of fittings . 29
10 Performance requirements . 30
11 Sealing rings . 31
12 Marking . 31
12.1 General . 31
12.2 Minimum required marking of pipes . 31
12.3 Minimum required marking of fittings . 32
12.4 Additional marking . 32
Annex A (normative) Utilization of PE recyclates . 33
A.1 General . 33
A.2 Agreed specification . 33
A.3 Additional specifications for recyclate and agreed specification . 34
Annex B (informative) General characteristics of PE pipes and fittings . 36
B.1 General . 36
B.2 Material characteristics . 36
B.3 Creep ratio . 36
B.4 Chemical resistance . 36
B.5 Abrasion resistance . 36
B.6 Hydraulic roughness . 37
B.7 Diametric deflection . 37
Annex C (informative) Product standards of components that can be connected to components
conforming to this document . 38
Bibliography . 39
European foreword
This document (EN 12666-1:2026) 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 November 2026, and conflicting national standards shall
be withdrawn at the latest by November 2026.
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 12666-1:2005+A1:2011.
This revision of the EN 12666 series is proposed by CEN/TC 155/WG 13 members in order to improve
the "level of sustainability" and the "environmental impact" of PE piping systems, whilst improving the
recommendations and safe use of recycled material.
Compared to the previous version EN 12666-1:2005+A1:2011, the main changes are listed below:
— the title has been changed;
— the document follows a new template;
— definitions for waste water and surface water have been added;
— material definitions have been updated in line with EN 14541-1:2022;
— the material Clause 5 has been rewritten;
— Annex A, utilization of PE recyclates has been added;
— in 12.2, the maximum marking interval has been changed.
This document is a part of a System Standard for plastics piping systems of particular materials for a
specified application. There are a number of such System Standards.
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).
System Standards are supported by separate standards on test methods to which references are made
throughout the System Standard.
System Standards are consistent with general standards on functional requirements and on
recommended practice for installation.
EN 12666:2026 consists of the following parts under the general Plastics piping systems for non-pressure
underground drains and sewers — Polyethylene (PE)
— Part 1: Specifications for pipes, fittings and the system (this document);
— Part 2: Assessment of conformity (CEN/TS).
This part of EN 12666 includes Annex B (informative) “General characteristics of PE pipes and fittings”.
[11]
For guidance for installation, see CEN/TS 1046 , and for guidance for design, see CEN/TS 15223:2025
[10]
.
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, Türkiye and the United
Kingdom.
1 Scope
This document specifies definitions and requirements for solid-wall pipes with or without internal skin
and smooth internal and external surfaces extruded from the same compound throughout the wall,
fittings and the system of polyethylene (PE) piping systems to be intended for use in non-pressure
underground drains and sewers for wastewater.
NOTE 1 Products complying with this document can also be used in non-pressure underground drains and
sewers for surface water.
This document is applicable to:
a) non-pressure drains and sewers, which are intended to be used buried underground outside the
building structure, reflected in the marking of products by “U”;
b) non-pressure drains and sewers, which are intended to be used buried underground both outside
(application area code “U”) and within the building structure, reflected in the marking of products by
“UD”.
This document specifies test methods referred to in this document and test parameters.
This document is applicable to pipes and fittings with or without an integral socket.
This document covers a range of pipe and fitting sizes, stiffness classes, tolerance classes 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 any relevant national regulations and installation
practices or codes.
[1]
In conjunction with CEN/TS 12666-2 it is applicable to PE pipes and fittings, their joints and to joints
with components of other plastics and non-plastics materials intended to be used for buried piping
systems for non-pressure drains and sewers.
The fittings can be manufactured by injection moulding or can be fabricated from pipes and/or
mouldings.
This document is applicable to PE pipes and fittings for the following types of joints:
— elastomeric ring seal joints;
— butt fused joints;
— electrofusion joints;
— mechanical joints.
NOTE 3 Pipes, fittings and other components conforming to any of the plastics product standards listed in the
Annex C (informative) can be used with pipes and fittings conforming to this document, provided they conform to
the requirements for joint dimensions given in Clause 7 and to the requirements of Clause 7 and Table 13.
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 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 12099, Plastics piping systems — Polyethylene piping materials and components — Determination of
volatile content
EN 15346:2024, Plastics — Recycled plastics — Characterization of poly(vinylchloride) (PVC) recyclates
EN ISO 472:2013, Plastics — Vocabulary (ISO 472:2013)
EN ISO 527-2, Plastics — Determination of tensile properties — Part 2: Test conditions for moulding and
extrusion plastics (ISO 527-2)
EN ISO 580, Plastics piping and ducting systems — Injection-moulded thermoplastics fittings — Methods
for visually assessing the effects of heating (ISO 580)
EN ISO 1043-1, Plastics — Symbols and abbreviated terms — Part 1: Basic polymers and their special
characteristics (ISO 1043-1)
EN ISO 1133-1, Plastics — Determination of the melt mass-flow rate (MFR) and the melt volume-flow rate
(MVR) of thermoplastics — Part 1: Standard method (ISO 1133-1)
EN 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 1167-1)
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 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: lmmersion
method, liquid pycnometer method and titration method (ISO 1183-1)
EN ISO 1183-2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density
gradient column method (ISO 1183-2)
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)
EN ISO 3451-1, Plastics — Determination of ash — Part 1: General methods (ISO 3451-1)
EN ISO 9969:2016, Thermoplastics pipes — Determination of ring stiffness (ISO 9969:2016)
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 13254, Thermoplastics piping systems for non-pressure applications — Test method for
watertightness (ISO 13254)
EN ISO 13257:2018, Thermoplastics piping systems for non-pressure applications — Test method for
resistance to elevated temperature cycling (ISO 13257:2018)
EN ISO 13259, Thermoplastics piping systems for underground non-pressure applications — Test method
for leaktightness of elastomeric sealing ring type joints (ISO 13259)
EN ISO 13263, Thermoplastics piping systems for non-pressure underground drainage and sewerage —
Thermoplastics fittings — Test method for impact strength (ISO 13263)
EN ISO 13264, Thermoplastics piping systems for non-pressure underground drainage and sewerage —
Thermoplastics fittings — Test method for mechanical strength or flexibility of fabricated fittings (ISO
13264)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 472:2013 and EN ISO 1043-
1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
drain
pipeline, usually underground, designed to carry wastewater from a source to a sewer
[SOURCE: EN 16323:2014, 2.2.3.1]
3.2
sewer
pipeline or other construction, usually underground, designed to carry wastewater from more than one
source
[SOURCE: EN 16323:2014, 2.2.3.12]
3.3
wastewater
water composed of any combination of water discharged from domestic, industrial or commercial
premises, surface run-off and accidentally any sewer infiltration water
[SOURCE: EN 16323:2014, 2.3.10.65, modified - sewage (deprecated) deleted]
3.4
surface water
water from precipitation, which has not seeped into the ground and is discharged to the drain or sewer
system directly from the ground or from exterior building surfaces
[SOURCE: EN 16323:2014, 2.1.1.3]
3.5
application area code
code used in the marking of pipes and fittings to indicate the application area(s) for which they are
intended, as follows:
U: for the area more than 1 m from the building to which the buried piping system is connected;
UD: for application area U and the area under and within 1 m from the building where the pipes and the
fittings are buried in ground and are connected to the soil and waste discharge system of the building.
3.6
Geometrical definitions
3.6.1
nominal size
DN
numerical designation of the size of a component, which is a convenient round number approximately
equal to the manufacturing dimension
Note 1 to entry: Nominal size is expressed in millimetres (mm).
Note 2 to entry: This designation is not used for thread components.
3.6.2
nominal size
DN/OD
nominal size, related to the outside diameter
3.6.3
nominal outside diameter
d
n
specified outside diameter assigned to a nominal size DN/OD
Note 1 to entry: Nominal size is expressed in millimetres (mm).
3.6.4
outside diameter
d
e
value of the measurement of the outside diameter through its cross-section at any point of a pipe or spigot
end, rounded up to the next greater 0,1 mm
3.6.5
mean outside diameter
d
em
value of the measurement of the outer circumference of a pipe or spigot end of a fitting in any cross-
section, divided by π (≈ 3,142), rounded up to the nearest 0,1 mm
3.6.6
mean inside diameter of a socket
d
sm
arithmetical mean of a number of measurements of the inside diameter of a socket in the same cross-
section
3.6.7
wall thickness
e
value of the measurement of the wall thickness at any point around the circumference of a component
3.6.8
mean wall thickness
e
m
arithmetical mean of a number of measurements of the wall thickness, regularly spaced around the
circumference and in the same cross-section of a component, including the measured minimum and the
measured maximum values of the wall thickness in that cross-section
3.6.9
pipe series (S)
[2]
number for pipe designation (see ISO 4065 )
Note 1 to entry: It is a dimensionless number.
3.6.10
standard dimension ratio (SDR)
numerical designation of a pipe series which is a convenient round number, approximately equal to the
dimension ratio of the nominal outside diameter, d , and the nominal wall thickness, e
n n
3.7
Mechanical definitions
3.7.1
nominal ring stiffness class (SN)
numerical designation of the ring stiffness of the pipe or fitting, which is a convenient round number,
indicating the minimum required ring stiffness of the pipe or stiffness of the fitting
3.8
Material definitions
3.8.1
virgin material
plastics material in the form of pellets, granules, powder, floc, etc. that has not been subjected to use or
processing other than that required for its initial manufacture
Note 1 to entry: Does not contain any reworked plastics material and/or plastics recyclate.
Note 2 to entry: Sometimes also referred to as “primary material” or “primary plastics feedstock”.
Note 3 to entry: It is understood that the addition of additives such as stabilizers and pigments is still resulting into
a virgin (plastics) material.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.2
reworked material
plastics material from rejected unused products or trimmings capable of being reclaimed within the same
process that generated it
Note 1 to entry: Reworked material does not change the status of the feedstock.
Note 2 to entry: This definition does not cover the conditions for the use of reworked material-which can be found
in the applicable product standard.
Note 3 to entry: Previously referred to as “own reprocessed material”.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.3
recyclate
plastics material resulting from the recycling of pre-consumer and post-consumer plastics products
Note 1 to entry: Also referred to as “secondary raw material” or “recycled plastics” or “regenerate”.
Note 2 to entry: Recycling can be chemical, physical or mechanical.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.4
pre-consumer material
plastics material diverted from the waste stream during a manufacturing process, excluding reworked
(plastics) material
Note 1 to entry: Previously referred to as “post-industrial material”.
Note 2 to entry: Different categories of pre-consumer material may be considered in the applicable product
standard.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.5
post-consumer material
plastics material generated by households or by commercial, industrial and institutional facilities in their
role as end-users of the product which can no longer be used for its intended purpose
Note 1 to entry: This includes returns of material from the distribution chain.
Note 2 to entry: Different categories of post-consumer material may be considered in the applicable product
standard.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.6
compound
clearly defined homogenous mixture of substances used for the manufacture of the product
Note 1 to entry: In general, the term “compound” is used for polyolefins and the term “formulation” for PVC.
Note 2 to entry: For metals and when dealing with water and food contact regulations the term “composition” is
often used instead of compound/formulation.
[20]
[SOURCE: EN 14541-1:2022 ]
3.8.7
agreed specification
specification of the relevant material characteristics agreed between the supplier of the recyclate and the
pipe and/or fitting manufacturer
Note 1 to entry: The agreed specification is often considered in the context of certification by a third party
organization.
4 Symbols and abbreviations
4.1 Symbols
For the purposes of this document, the following symbols apply.
d nominal diameter of the main of a branch
n,1
nominal diameter of the branch of a branch
dn,2
L insert length
Z Z Z design length of a fitting
1, 2, 3
α nominal angle of fitting
4.2 Abbreviations
For the purposes of this document, the following abbreviations apply.
DN nominal size
DN/ID nominal size related to inside diameter
DN/OD nominal size related to outside diameter
PE polyethylene
S pipe series S
SDR standard dimension ratio
SN ring stiffness class
5 Material
5.1 General
The compound for production of pipes and fittings shall be PE-base material to which additives can be
added to enable conformity with the requirements of this document.
PE material may be virgin material, reworked material or recyclates (pre- or post-consumer).
Recyclates are permitted if they comply with Annex A.
The compound (including virgin material, reworked material, recyclates or a mixture, if applicable) shall
comply with the requirements given in 5.2.
The maximum amount of recyclate in the compound is calculated based on the amount of separate
recyclate added to the compound plus the amount of recyclate present in reworked material which is
added to the compound.
Test results with 100 % virgin material and test results with the maximum amount of recyclates with the
same agreed specification shall be taken as proving conformity for all recyclate amounts in between.
NOTE Additional information on general characteristics of PE pipes and fittings is given in informative
Annex B.
5.2 Compound characteristics of pipe and injection moulded fittings
When tested in accordance with the test method as specified in Table 1 using the indicated parameters,
the compound shall have characteristics conforming to the requirements given in Table 1.
Table 1 — Characteristics of PE compound for pipes and injection-moulded fittings
Characteristic Requirements Test parameters Test method
Resistance to No failure during End caps Type A or Type B EN ISO 1167-1
internal pressure the test period and
Test temperature 80 °C
a b
165 h
EN ISO 1167-2
Orientation Free
Number of test 3
pieces
Circumferential 4,0 MPa
stress
Conditioning Shall conform to
period EN ISO 1167-1
Type of test Water-in-water
Test period 165 h
Resistance to No failure during End caps Type A or Type B EN ISO 1167-1
internal pressure the test period and
Test temperature 80 °C
a b
1 000 h
EN ISO 1167-2
Orientation Free
Number of test 3
pieces
Circumferential 2,8 MPa
stress
Conditioning Shall conform to
period EN ISO 1167-1
Type of test Water-in-water
Test period 1 000 h
Melt mass-flow ≤ 1,6 g/10 min Temperature 190 °C EN ISO 1133-1
c
rate
Loading mass 5 kg
Characteristic Requirements Test parameters Test method
Thermal stability, ≥ 20 min Temperature 200 °C EN ISO 11357-6
OIT
Atmosphere Oxygen
a
For the extrusion compound this test shall be carried out in the form of an injection-moulded or extruded sample
of a solid wall pipe made from the relevant compound.
b
For injection-moulding compound, 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 compound.
c
This requirement only applies to pipes and fittings intended to be welded.
5.3 Sealing ring retaining components
It is permitted that sealing rings are retained using components made from any polymer.
5.4 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.
6 Appearance and colour
6.1 Appearance
When viewed without magnification, the following requirements apply:
— internal and external surfaces of pipes and fittings shall be smooth, clean and free from defects likely
to prevent their conformity to this document. The manufacturer shall define acceptance criteria for
visual appearance;
NOTE Examples of defects can be grooving, blistering, impurities or pores.
— pipe ends shall be cleanly cut and the ends of pipes and fittings shall be square to their axis.
Electrofusion fittings may feature exposed metallic components.
6.2 Colour
The pipes and fittings shall be coloured through the wall. The colour should preferably be black or as
agreed between manufacturer and purchaser.
A deviating colour for a co-extruded inner skin is permitted provided the material of this skin conforms
to Clause 5.
7 Geometrical characteristics
7.1 General
Dimensions shall be measured according to EN ISO 3126.
NOTE The figures in Clause 7 are schematic sketches only, to indicate the relevant dimensions. They do not
necessarily represent manufactured components.
7.2 Dimensions of pipes
7.2.1 Outside diameter
The mean outside diameter, d , shall conform to Table 2.
em
Table 2 — Mean outside diameters
Dimensions in millimetres
Nominal size Nominal outside diameter Mean outside diameter
DN/OD
d d d
n em,min em,max
110 110 110,0 111,0
125 125 125,0 126,2
160 160 160,0 161,5
200 200 200,0 201,8
250 250 250,0 252,3
315 315 315,0 317,9
355 355 355,0 358,2
400 400 400,0 403,6
450 450 450,0 454,1
500 500 500,0 504,5
560 560 560,0 565,0
630 630 630,0 635,7
710 710 710,0 716,4
800 800 800,0 807,2
1 000 1 000 1 000,0 1 009,0
1 200 1 200 1 200,0 1 210,0
1 400 1 400 1 400,0 1 410,0
1 600 1 600 1 600,0 1 610,0
7.2.2 Length of pipes
The effective length of a pipe, l, shall be not less than that declared by the manufacturer when measured
as shown in Figure 1.
Figure 1 — Effective length of pipes for single-socketed pipes with ring seal and plain-ended
pipes, both with and without chamfer
7.2.3 Wall thickness
The wall thickness, e, shall conform to Table 3, where a maximum wall thickness at any point of 1,25e
min
is permitted provided that the mean wall thickness, e , is less than or equal to the specified e . The e
m m,max m
value needs not to be determined if the e value is less than or equal to e in Table 3.
max m,max
Table 3 — Wall thicknesses
Dimensions in millimetres
a
Nominal Nominal Wall thickness
size outside
DN/OD diameter
b
SN 2 SN 4 SN 8 SN 16
b
S 16 S 12,5 S 10 S 8
b
SDR 33 SDR 26 SDR 21 SDR 17
c c c c
d e e e e e e e e
n min m,max min m,max min m,max min m,max
d d
110 110 – – 4,2 4,9 5,3 6,1 6,6 7,5
d d
125 125 – – 4,8 5,5 6,0 6,9 7,4 8,4
d d
160 160 – – 6,2 7,1 7,7 8,7 9,5 10,7
d d
7,7 8,7 9,6 10,8 11,9 13,3
200 200 – –
250 250 7,7 8,7 9,6 10,8 11,9 13,3 14,8 16,5
315 315 9,7 10,9 12,1 13,6 15,0 16,8 18,7 21,7
355 355 10,9 12,2 13,6 15,2 16,9 19,7 21,1 24,5
400 400 12,3 13,8 15,3 17,1 19,1 22,2 23,7 27,5
450 450 13,8 15,4 17,2 20,0 21,5 24,8 26,7 30,9
500 500 15,3 17,1 19,1 22,2 23,9 27,4 29,7 34,4
560 560 17,2 20,0 21,4 24,9 26,7 30,9 33,2 38,4
630 630 19,3 22,5 24,1 28,0 30,0 34,7 37,4 43,3
710 710 21,8 25,3 27,2 31,5 33,9 39,2 42,1 48,7
800 800 24,5 28,4 30,6 35,4 38,1 44,1 47,4 54,8
1 000 1 000 30,6 35,4 38,2 44,2 47,7 55,1 - -
1 200 1 200 36,7 42,4 45,9 53,0 57,2 66,0 - -
1 400 1 400 42,9 49,6 53,5 61,8 – – - -
1 600 1 600 49,0 56,6 61,2 70,6 – – - -
a [13]
The tolerances for wall thicknesses conform to ISO 11922-1 grade W for wall thickness equal to or less than
16 mm and grade X for wall thickness larger than 16 mm.
b
SN 2, S 16 and SDR 33 are applicable for application area “UD” only”.
c [2]
The e -values are in conformance with ISO 4065:2018 .
min
d [19]
For sizes DN 110 to 200 in SN 2 reference is made to EN 1519-1:2019, Table 3 and Table 4 , pipe series S16.
Such pipes may be used outside the application area B when encased in concrete or laid in ducts.
7.3 Dimensions of fittings
7.3.1 Outside diameter for spigots
The mean outside diameter, d , of the spigot shall conform to Table 2.
em
7.3.2 Outside diameter for spigots with close tolerances (Type CT)
For the purposes of this document in addition to the dimensions and tolerances given in Table 2 for spigot
ends of fittings, tolerances that are in accordance with EN 1401-1 may be used.
If these tolerances, classified as close tolerances (CT), are required the mean outside diameter, d , of the
em
spigot and the tolerances shall conform to Table 4.
Table 4 — Mean outside diameters for spigots with close tolerances type CT
Dimensions in millimetres
Nominal size Nominal outside Mean outside diameter
diameter
DN/OD d d d
n em,min em,max
110 110 110,0 110,3
125 125 125,0 125,3
160 160 160,0 160,4
200 200 200,0 200,5
250 250 250,0 250,5
315 315 315,0 315,6
355 355 355,0 355,7
400 400 400,0 400,7
450 450 450,0 450,8
500 500 500,0 500,9
630 630 630,0 631,1
Spigot ends of fittings with mean outside diameters conforming to Table 4 may be used with pipes and
fittings conforming to EN 1401-1 provided that the socket(s) for these pipes and fittings are intended to
be used with elastomeric ring seal joints.
NOTE Spigots ends of fittings with mean outside diameters conforming to Table 4 are normally injection-
moulded or machined.
7.3.3 Design lengths
The design lengths, Z , shall be declared by the manufacturer.
d
The design lengths (see the dimensions Z in Figures 8 to 12 and Figures 15 to 20) are intended to assist
d
[3]
in the design of moulds and are not intended to be used for quality control purposes. ISO 265-1 may be
used as a guideline.
7.3.4 Wall thicknesses of the body of a fitting
7.3.4.1 The minimum wall thickness, e , of the body or the spigot of a fitting shall conform to
min
Table 3, except that a reduction of 5 % resulting from core shift is permitted. In such a case, the mean of
two opposite wall thicknesses shall be equal to or exceed the values given in this table.
7.3.4.2 Where a fitting or adaptor provides for a transition between two nominal sizes, the wall
thickness of each connecting part shall conform to the requirements for the applicable nominal size. In
such a case the wall thickness of the fitting body is permitted to change gradually from one wall thickness
to the other.
7.3.4.3 The wall thickness of fabricated fittings, except for spigot and socket, may be changed locally
by the fabrication process, provided that the minimum wall thickness of the body conforms to e as
3,min
given in Table 6 for the size and pipe series concerned.
7.4 Dimensions of sockets and spigots
7.4.1 Elastomeric ring seal sockets and spigots
7.4.1.1 Diameters and lengths
The diameters and lengths of elastomeric ring seal sockets and lengths of spigots shall conform to Table 5
(see Figures 2, 3, 4 or 5, as applicable).
Where sealing rings are firmly retained, the dimensions for the minimum value for A and the maximum
value for C shall be measured to the effective sealing point (see Figure 4) as specified by the manufacturer.
This point shall give a full sealing action.
Different designs of elastomeric ring seal sockets are permitted, provided they conform to the
requirements given in Table 12.
Table 5 — Socket diameters and lengths of sockets and spigots
Dimensions in millimetres
Nominal size Nominal Socket Spigot
DN/OD outside
diameter
a
d d A C L
n sm,min min max 1,min
110 110 111,1 40 40 62
125 125 126,3 43 43 68
160 160 161,6 50 50 82
200 200 201,9 58 58 98
250 250 252,4 68 68 118
315 315 318,0 81 81 144
355 355 358,3 89 89 160
400 400 403,7 98 98 178
450 450 454,2 108 108 198
500 500 504,6 118 118 218
560 560 565,1 130 130 242
630 630 635,8 144 144 270
a
The socket is designed for an effective length of pipe of 6 m.
,
For sockets and spigots that have a nominal outside diameter greater than 630 mm, the values of dsm,min
A , C and L shall be calculated using the following equations:
min max 1,min
A = (0,2d + 18) mm;
min n
C = (0,2d + 18) mm;
max n
d = 1,0092d mm;
sm,min n
L = (0,4d + 18) mm.
1,min n
For pipe lengths longer than 6 m the length of engagement, A, in the socket shall be calculated from the
formula: A = (0,2d + 3 × l) mm, where l is the pipe length, in metres.
n
Ring seal socket
with chamfer
Ring seal socket
without chamfer
Figure 2 — Dimensions of sockets for elastomeric ring seal joints
Figure 3 — Typical groove designs for elastomeric ring seal sockets
Figure 4 — Example for measuring the effective sealing point
Figure 5 — Spigot lengths
7.4.1.2 Wall thicknesses of sockets
The wall thicknesses of sockets, e and e (see Figure 2), except the socket mouth, shall conform to
2 3
Table 6.
A reduction of 5 % of e2 and e3 resulting from core shift is permitted. In such a case the mean of two
opposite wall thicknesses shall be equal to or exceed the applicable values given in Table 6.
Table 6 — Wall thicknesses of sockets
Dimensions in millimetres
Nominal Nominal Wall thickness
size outside
a
SN 2 SN 4 SN 8 SN 16
DN/OD diameter
a
S 16 S 12,5 S 10 S 8
a
SDR 33 SDR 26 SDR 21 SDR 17
d e e e e e e e e
n 2,min 3,min 2,min 3,min 2,min 3,min 2,min 3,min
110 110 - - 3,8 3,2 4,8 4,0 6,0 5,0
125 125 - - 4,4 3,6 5,4 4,5 6,7 5,6
160 160 - - 5,6 4,7 7,0 5,8 8,6 7,2
200 200 - - 7,0 5,8 8,7 7,2 10,8 9,0
250 250 7,0 5,8 8,7 7,2 10,8 9,0 13,4 11,1
315 315 8,8 7,3 10,9 9,1 13,5 11,3 16,9 14,1
355 355
...