prEN 489-1

• Abstract:

  This document specifies requirements and test methods for joint casing systems for single and twin pipes between adjacent factory-made pipe, and/or fitting and/or valve assemblies for buried heating and cooling water networks with rigid pipe systems with metal service pipes in accordance with EN 13941-1 [4] and EN 13941-2 [5] as well as rigid pipe systems with plastic service pipes according to series EN 17415 and flexible pipe systems with metal service pipes according to EN 15632-4 .; NOTE There are no differences in requirements for single and twin pipe joint casing systems.; For bedding materials other than those defined in 5.2.3 additional precautions are defined inEN 13941-2 [5].

• Status: Not Published
• Publication Date: 13-Aug-2028
• ICS: 23.040.07 - Pipeline and its parts for district heat
• ICS: 23.040.60 - Flanges, couplings and joints
• Technical Committee: CEN/TC 107 - Pre-fabricated district heating pipe systems
• Drafting Committee: CEN/TC 107/WG 4 - Joints
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 20-Aug-2026
• Due Date: 29-Mar-2027
• Completion Date: 20-Aug-2026
• Ref Project: oSIST prEN 489-1:2026 - District heating pipes - Bonded single and twin pipe systems for buried hot and coldwater networks - Part 1: Joint casing assemblies and thermal insulation for hot and cold-water networks with metal service pipes in accordance with EN 13941-series

• Revises: EN 489-1:2019 - District heating pipes - Bonded single and twin pipe systems for buried hot water networks - Part 1: Joint casing assemblies and thermal insulation for hot water networks in accordance with EN 13941-1
• Effective Date: 06-Aug-2025

Overview

prEN 489-1:2026 is a draft European standard prepared by CEN/TC 107, focusing on the requirements and testing methods for joint casing assemblies and thermal insulation in bonded single and twin pipe systems. These systems are designed for buried hot and cold-water networks, using metal service pipes in accordance with the EN 13941 series. The standard applies to rigid and flexible district heating and cooling pipe systems and sets out essential guidelines to ensure durability, safety, and energy efficiency in underground networks.

This standard supersedes EN 489-1:2019 and includes updates for flexible pipe systems per EN 15632-4 and systems using plastic service pipes per EN 17415. Its key aim is to promote reliability, watertightness, and strong insulation performance in district heating and cooling infrastructure.

Key Topics

• Scope and Applicability: Specifies requirements for joint casing systems used between factory-made pipe, fitting, and valve assemblies in buried district heating and cooling water networks.
• Joint Casing Assemblies: Details both single and twin pipe joint casing systems, evaluating their mechanical strength and thermal properties.
• Type Testing and Compliance: Defines procedures for type testing, including soil stress, water tightness, stress crack resistance, and thermal insulation properties.
• Installation Guidance: Outlines requirements for installation instructions, including preparation, equipment, and quality assurance checks.
• Product Identification and Marking: Sets marking requirements to ensure traceability and compliance of all components in the pipe systems.
• Test Methods: Includes comprehensive test methods for soil stress, water tightness, foam density, compressive strength, and fusion weld integrity.
• Quality Control: Recommends surveillance systems for monitoring performance and detecting faults or leakage in operational networks.

Applications

prEN 489-1:2026 is crucial in the construction and maintenance of modern district heating and cooling networks. Its implementation delivers practical value in the following ways:

• Infrastructure Longevity: Ensures hermetic joint casing assemblies capable of withstanding soil, temperature fluctuations, and mechanical stress, which results in extended service life of underground pipeline systems.
• Energy Efficiency: Sets requirements for thermal insulation quality (e.g., polyurethane foam) in buried pipes, helping to minimize energy losses from hot and cold-water networks.
• Leak Prevention: Mandates water tightness and robust stress crack resistance, reducing the risk of water ingress and pipe failure-critical for urban heating and cooling systems.
• Safety and Compliance: Provides a framework for mandatory product marking and documentation, supporting regulatory compliance and safety in piping installations.

These requirements benefit a range of stakeholders, including utility providers, pipeline manufacturers, contractors, and engineers working on district energy projects in cities and industrial environments.

Related Standards

• EN 13941-1 & EN 13941-2: Address general requirements and installation techniques for pre-insulated bonded pipe systems for district heating.
• EN 17415-series: Relates to rigid pipe systems with plastic service pipes.
• EN 15632-4: Covers flexible pipe systems with metal service pipes.
• EN 253: Describes specification and test methods for factory-made bonded single pipe systems for directly buried networks.
• EN 14419: Specifies requirements for surveillance systems monitoring district heating pipes.
• ISO 16770, EN ISO 1133-1, EN 12814-1, EN 17248: Provide supplementary guidance on plastics testing, welding, and terminology in pipeline systems.

By adhering to prEN 489-1, stakeholders help ensure safe, reliable, and efficient thermal energy networks-supporting the expansion of sustainable district heating and cooling throughout Europe.

Keywords: prEN 489-1, district heating pipes, bonded pipe systems, joint casing assemblies, thermal insulation, hot and cold-water networks, CEN, EN 13941, quality control, underground piping, energy efficiency, water tightness, installation requirements, compliance testing.

SLOVENSKI STANDARD
01-oktober-2026
Cevi za daljinsko ogrevanje - Predizolirani enocevni ali dvocevni sistemi za
vkopana vročevodna omrežja - 1. del: Spojeni cevni sestavi in toplotna izolacija za
vročevodna in hladnovodna omrežja vezane kovinske cevi v skladu z EN 13941-1
District heating pipes - Bonded single and twin pipe systems for buried hot and coldwater
networks - Part 1: Joint casing assemblies and thermal insulation for hot and cold-water
networks with metal service pipes in accordance with EN 13941-series
Fernwärmerohre - Einzel- und Doppelrohr-Verbundsysteme für erdverlegte Fernwärme-
und Fernkältenetze - Teil 1: Mantelrohrverbindungen und Wärmedämmung für
Fernwärme- und Fernkältenetze mit metallischen Versorgungsleitungen nach EN
13941‑1
Tuyaux de chauffage urbain - Systèmes bloqués de tuyaux monotubes et bitubes pour
les réseaux d'eau chaude et froide enterrés - Partie 1 : Kits de protection et d’isolation
des jonctions de tubes pour les réseaux d'eau chaude et froide avec tubes de service en
acier conformes à la série EN 13941
Ta slovenski standard je istoveten z: prEN 489-1
ICS:
23.040.07 Cevovodi za daljinsko Pipeline and its parts for
ogrevanje in njihovi deli district heat
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2026
ICS 23.040.07; 23.040.60 Will supersede EN 489-1:2019
English Version
District heating pipes - Bonded single and twin pipe
systems for buried hot and coldwater networks - Part 1:
Joint casing assemblies and thermal insulation for hot and
cold-water networks with metal service pipes in
accordance with EN 13941-series.
Tuyaux de chauffage urbain - Systèmes bloqués de Fernwärmerohre - Einzel- und Doppelrohr-
tuyaux monotubes et bitubes pour les réseaux d'eau Verbundsysteme für erdverlegte Fernwärme- und
chaude et froide enterrés - Partie 1 : Kits de protection Fernkältenetze - Teil 1: Mantelrohrverbindungen und
et d'isolation des jonctions de tubes pour les réseaux Wärmedämmung für Fernwärme- und Fernkältenetze
d'eau chaude et froide avec tubes de service en acier mit metallischen Versorgungsleitungen nach EN
conformes à la série EN 13941 13941-1
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 107.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

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. prEN 489-1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Requirements . 6
4.1 General . 6
4.2 General requirements for type testing . 7
4.2.1 General . 7
4.2.2 General requirements for the joint casing system . 7
4.2.3 Installation of the joint casing system . 7
4.3 Requirements for joint casing systems of single and twin pipes . 7
4.3.1 Joint casing . 7
4.3.2 Polyurethane (PUR) foam thermal insulation . 7
4.3.3 Soil stress test . 8
4.3.4 Water tightness . 8
4.3.5 Stress crack resistance (SCR) . 8
4.3.6 Plugs . 8
4.3.7 Melt mass-flow rate (MFR) of welded plug . 8
4.4 Installation instructions . 8
4.4.1 General . 8
4.4.2 Requirements for installation instruction . 9
4.5 Surveillance system . 9
5 Test methods . 9
5.1 Preparation of test specimen . 9
5.2 Soil stress test . 9
5.2.1 General . 9
5.2.2 Sand box . 9
5.2.3 Sand for soil stress test . 11
5.2.4 Test specimens . 11
5.2.5 Sand box test . 12
5.3 Water tightness test . 12
5.4 Stress crack resistance (SCR) test . 12
5.5 Melt mass flow rate (MFR) test . 13
5.6 Joint thermal insulation . 13
5.6.1 Foam density . 13
5.6.2 Compressive strength . 13
5.6.3 Cell structure . 13
5.6.4 Water absorption at elevated temperature . 13
5.7 Bending test on welded plugs . 13
6 Marking . 15
6.1 General . 15
6.2 Joint casing . 15
6.3 Shrink sleeve . 16
6.4 Adhesive strip . 16
6.5 Plugs . 16
7 Reporting . 16
7.1 Test report . 16
7.2 Summary of test results . 17
Annex A (normative) Overview of available joint casing systems . 18
Annex B (informative) Drawings for the principle of joint casing systems . 21
Annex C (informative) Guidelines for inspection and testing . 22
C.1 General . 22
C.2 Manufacturer's type test . 22
C.3 Manufacturer’s quality control . 22
C.4 Additional inspection . 22
Bibliography . 24
European foreword
This document (prEN489-1:2026) has been prepared by Technical Committee CEN/TC"107", the
secretariat of which is held by DS.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 489-1:2019 [1].
In comparison with the previous edition, the following technical modifications have been made:
— The scope was changed to cover also flèxiblè pipe systems according to EN 15632-4 [2] with metal
service pipes;
— editorial adjustments and updates to references throughout the document;
— minimum requirement and evidence of the degree of crosslinking in crosslinked PE-materials was
added in 4.3.1;
— clause 4.3.3 has been reworded to make it clearer;
— clarification of witness during the preparation of the test specimen in 5.1;
— the permissible loss of sand in the sandbox test has been reduced in 5.2.5;
— determination of the dimensions of the joint casings in the SCR test in 5.4;
— joint casing system 1.5 was added to Annex A;
— Schematic drawings of joint casing systems have been newly included in Annex B;
— additions to the inspection of joint casing systems in Annex C.
Introduction
The first edition of EN 489 was approved in 1994 and updated in 2003, 2009 and 2019.
With the 2019 edition, the number of the standard was changed from EN 489 to EN 489-1 in order to
include EN 489-2 for joint casing systems for flèxiblè pipe systems in the same series of standards.
This spècification is part of the series of standards for bonded systems using polyurethane foam thermal
insulation applied to bond to a steel service pipe and a polyethylene casing.
For information on the minimum expected thermal life with operation at various temperatures with
respect to PUR foam performance see FprCEN/TR 18341 [3].
1 Scope
This document spècifiès requirements and test methods for joint casing systems for single and twin
pipes between adjacent factory-made pipe, and/or fitting and/or valve assemblies for buried heating
and cooling water networks with rigid pipe systems with metal service pipes in accordance with EN
13941-1 [4] and EN 13941-2 [5] as well as rigid pipe systems with plastic service pipes according to
series EN 17415 and flèxiblè pipe systems with metal service pipes according to EN 15632-4 .
NOTE There are no differences in requirements for single and twin pipe joint casing systems.
For bedding materials other than those dèfinèd in 5.2.3 additional precautions are dèfinèd inEN 13941-2
[5].
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 16770, Plastics — Determination of environmental stress cracking (ESC) of polyethylene — Full-notch
creep test (FNCT)
EN 253, District heating pipes - Bonded single pipe systems for directly buried hot water networks - Factory
made pipe assembly of steel service pipe, polyurethane thermal insulation and a casing of polyethylene
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 1133-1:2022)
EN ISO 10147, Pipes and fittings made of crosslinked polyethylene (PE-X) - Estimation of the degree of
crosslinking by determination of the gel content (ISO 10147:2011)
EN 12814-1, Testing of welded joints of thermoplastics semi-finished products - Part 1: Bend test
EN 14419, District heating pipes - Bonded single and twin pipe systems for buried hot water networks -
Surveillance systems
EN 17248, District heating and district cooling pipe systems - Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and dèfinitions given in EN 17248 apply.
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4 Requirements
4.1 General
All joints shall fulfil the requirements of Table 1 :
Table 1 — Requirements to be tested on different systems
Joint requirements Welded joint Sealed joint
Soil stress - 4.3.3
Stress Crack Resistance SCR 4.3.5 -
Water tightness 4.3.4 4.3.4
Foam properties 4.3.2 4.3.2
Plug properties 4.3.6 4.3.6
4.2 General requirements for type testing
4.2.1 General
Each joint casing system to be tested shall be provided with product data sheet, installation instruction
and - if relevant - safety data sheet for any major component.
NOTE Annex A gives a categorization of different joint casing systems and Annex B shows these in schematic
drawings.
4.2.2 General requirements for the joint casing system
The joint casing system shall be:
— watertight;
— able to withstand radial forces;
— able to withstand effects of temperature and temperature variations.
4.2.3 Installation of the joint casing system
Each individual step in the installation of a joint shall follow the system supplier's installation
instructions in order to ensure that the joint obtained is equivalent to the joint as previously type-tested.
4.3 Requirements for joint casing systems of single and twin pipes
4.3.1 Joint casing
Joint casings can be made of non-crosslinked (PE) or crosslinked (PE-X) material. Joint casings of PE-X
can be crosslinked along their entire length or only at the ends where the sealings are made. The degree
of cross-linking shall be at least 40% when tested in accordance with EN ISO 10147.
4.3.2 Polyurethane (PUR) foam thermal insulation
4.3.2.1 General
The installation of the on-site fillèd polyurethane foam thermal insulation (PUR) or the pre-fabricated
thermal joint insulation shall be carried out according to the supplier’s installation instruction.
The thermal insulation shall completely fill the joint.
4.3.2.2 Foam density
The requirement for foam density shall be in accordance with EN 253.
4.3.2.3 Compressive strength
The requirement for compressive strength shall be in accordance with EN 253.
4.3.2.4 Cell structure
The requirement for the composition and the cell structure shall be in accordance with EN 253.
4.3.2.5 Water absorption at elevated temperature
The requirement for water absorption at elevated temperature shall be in accordance with EN 253.
4.3.3 Soil stress test
Joint casing systems shall, as mentioned in Table 1, pass the soil stress test in accordance with 5.2.
A soil stress test is considered passed when the water tightness test according to 4.3.4 executed after
the soil stress test shows no water ingress, independently of the visual appearance of the joint.
4.3.4 Water tightness
For all joint casing systems it applies that no water ingress shall be detected after the water tightness
test in accordance with 5.3.
4.3.5 Stress crack resistance (SCR)
Each circumferential and longitudinal weld shall be individually tested for SCR. When tested in
accordance with 5.4 the time until failure shall be at least 115 h.
4.3.6 Plugs
4.3.6.1 General
Joint casing system to be foamed on-site shall have its foaming and venting holes securely closed by:
• plugs sealed by adhesive or similar (sealed plugs);
• plugs fused by welding (welded plugs).
4.3.6.2 Sealed plugs
Sealed plugs shall be tested following the approach of the sealed joint casing system. This means the
sealed plugs shall be present in the soil stress test and water tightness test as part of the joint casing
system.
4.3.6.3 Welded plugs
Welded plugs shall fulfil the requirement of the bending test in accordance with 5.7 and shall be
performed after the water tightness test.
They shall be tested following the approach of the joint casing system in which they are used.
4.3.7 Melt mass-flow rate (MFR) of welded plug
The melt mass-flow rate (MFR) of the welded plug material shall be determined in accordance with
5.5 . The MFR shall be within 0,2 ≤ MFR ≤ 1,0 g/10 min.
4.4 Installation instructions
4.4.1 General
Installation instructions, crucial for the quality of the joint, shall be a part of the manufacturer's
documentation. These installation instructions shall be a part of the type test report.
The installation instructions shall, as a minimum, deal with the topics mentioned in 4.4.2 and shall be
followed at any installation.
4.4.2 Requirements for installation instruction
The intention of the installation instruction is to enable the installer to install the product in a correct
way. It is the responsibility of the supplier to formulate a complete instruction, but it has as a minimum
to deal with the following topics:
a) storage conditions of components, see also EN 13941-2 [5];
b) environmental conditions for installation;
c) idèntification of components;
d) required installation equipment and tools;
e) proper procedures for the cleaning, drying and preparation of surfaces;
f) test procedures for leak-tightness of joint if relevant;
g) recommendation to check the quality and consistency of the foam components;
h) necessary quantity of foaming material for each joint dimension;
i) procedures for on-site inspection.
4.5 Surveillance system
When measuring elements for a surveillance system are installed in the joint, proper procedures for
connecting the surveillance system shall be spècifièd before the assembly takes place. This spècification
shall comply with EN 14419 .
5 Test methods
5.1 Preparation of test specimen
The test specimens, to be used in a type test, shall be prepared under the witness (physical in person
or from a third party accepted by the testing institute) of the testing institute doing the test, in order to
make sure that the installation instructions provided by the manufacturer are followed.
5.2 Soil stress test
5.2.1 General
The soil stress test shall be carried out as follows in 5.2.2 to 5.2.5 .
5.2.2 Sand
...