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

This document specifies requirements and test methods for joints between adjacent factory made pipe, and/or fitting and/or valve assemblies for buried hot water networks in accordance with EN 13941-1.

Fernwärmerohre - Einzel- und Doppelrohr-Verbundsysteme für erdverlegte Fernwärmenetze - Teil 1: Mantelrohrverbindungen und Wärmedämmung für Fernwärmenetze nach EN 13941-1

Dieses Dokument legt Anforderungen und Prüfverfahren für Verbindungen zwischen angrenzenden werkseitig hergestellten Rohr- und/oder Formteil- und/oder Armaturenbaugruppen für erdverlegte Heißwasser-Fernwärmenetze nach EN 13941-1 fest.

Tuyaux de chauffage urbain - Systèmes bloqués de tuyaux monotubes et bitubes pour les réseaux d'eau chaude enterrés - Partie 1 : Assemblage des joints de tube de protection pour les réseaux d'eau chaude conformes à l'EN 13941-1

Le présent document spécifie les prescriptions et les méthodes d'essai s’appliquant aux assemblages de tuyaux et/ou raccords et/ou robinets préisolés adjacents réalisés en usine pour réseaux d'eau chaude enterrés conformes à l’EN 13941-1.

Cevi za daljinsko ogrevanje - Predizolirani enocevni ali dvocevni sistemi za vkopana vročevodna omrežja - 1. del: Spojeni cevni sestavi in toplotna izolacija za vročevodna omrežja v skladu z EN 13941-1

Ta evropski standard določa zahteve in preskusne metode za spoje med bližnjimi tovarniško izdelanimi cevmi in/ali sestave fitingov in/ali ventilov za vkopana vročevodna omrežja v skladu s standardom EN 13941-1.

General Information

• Status: Published
• Publication Date: 15-Oct-2019
• Withdrawal Date: 29-Apr-2020
• 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: 9092 - Decision on results of review/2YR ENQ - revise - Review Enquiry
• Start Date: 01-Aug-2025
• Completion Date: 23-Sep-2025
• Ref Project: SIST EN 489-1:2020 - 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

Relations

• Replaces: EN 489:2009 - District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Joint assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene
• Effective Date: 21-Jun-2017

Overview

EN 489-1:2019 (CEN) specifies requirements and test methods for joint casing assemblies and thermal insulation used in bonded single and twin pipe systems for buried hot water district heating networks in accordance with EN 13941-1. It covers factory-made joints between adjacent pipes, fittings and valves and is applicable to systems using polyurethane (PUR) foam insulation bonded to a steel service pipe and a polyethylene casing.

Key topics and technical requirements

• Scope & applicability: Applies to joints in buried hot water networks (single and twin pipe systems); supersedes EN 489:2009.
• Watertightness: All joint casing systems must be watertight - no water ingress after the specified water‑tightness test.
• Mechanical performance: Joints must withstand longitudinal forces, radial forces and bending moments, and effects of temperature variation.
• Polyurethane (PUR) foam: Foam density, compressive strength, average cell size and water absorption requirements reference EN 253.
• Soil stress test: Joints are tested in a sand box under defined loading conditions; test specimens (minimum 2.5 m length) include at least 160 mm and 250 mm casing diameters.
• Stress crack resistance (SCR): Each circumferential and longitudinal weld shall pass an SCR test with a minimum time‑to‑failure of 300 h; if SCR testing is not possible, the soil stress test is used instead.
• Plugs: Requirements for on‑site foaming plugs (sealed or welded) are specified. Welded plug material MFR must be between 0.2 and 1.0 g/10 min; welded plugs undergo a bending test after watertightness testing.
• Type testing & test specimen preparation: Specimens must be prepared under the witness of the testing institute following the supplier’s installation instructions.
• Documentation & marking: Manufacturers must supply installation instructions, product data sheets and relevant safety information; marking requirements for joints are included.

Practical applications and users

This standard is essential for:

• Manufacturers of bonded district heating pipes, joint casings, fittings and valves - for product design, type testing and CE/national compliance.
• Designers and engineers specifying buried hot water networks to ensure joint integrity and long‑term thermal performance.
• Installation contractors - to follow approved installation procedures that reproduce type-tested joints.
• Test laboratories and certification bodies - to perform soil stress, watertightness, SCR and plug tests.
• Asset owners and operators seeking assurance of leak tightness, mechanical resilience and insulation performance.

Related standards

• EN 13941-1 (design of systems)
• EN 253 (PUR foam properties for district heating pipes)
• EN 13941-2 (installation)
• EN 17248 (terms and definitions)
• EN 14419 (surveillance systems)

Keywords: EN 489-1:2019, district heating pipes, joint casing assemblies, bonded single and twin pipe systems, thermal insulation, PUR foam, soil stress test, stress crack resistance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2020
Nadomešča:
SIST EN 489:2009
Cevi za daljinsko ogrevanje - Predizolirani enocevni ali dvocevni sistemi za
vkopana vročevodna omrežja - 1. del: Spojeni cevni sestavi in toplotna izolacija za
vročevodna omrežja v skladu z EN 13941-1
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
Fernwärmerohre - Einzel- und Doppelrohr-Verbundsysteme für erdverlegte Heißwasser-
Fernwärmenetze - Teil 1: Mantelrohrverbindungen und Wärmedämmung für Heißwasser-
Fernwärmenetze nach EN 13941-1
Tuyaux de chauffage urbain - Systèmes bloqués de tuyaux monotubes et bitubes pour
les réseaux d'eau chaude enterrés - Partie 1 : Assemblage des joints de tube de
protection pour les réseaux d'eau chaude conformes à l'EN 13941-1
Ta slovenski standard je istoveten z: EN 489-1:2019
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
91.140.65 Oprema za ogrevanje vode Water heating equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 489-1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2019
EUROPÄISCHE NORM
ICS 23.040.07; 23.040.60 Supersedes EN 489:2009
English Version
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
Tuyaux de chauffage urbain - Systèmes bloqués de Fernwärmerohre - Einzel- und Doppelrohr-
tuyaux monotubes et bitubes pour les réseaux d'eau Verbundsysteme für erdverlegte Heißwasser-
chaude enterrés - Assemblage des joints de tube de Fernwärmenetze - Teil 1: Mantelrohrverbindungen
protection pour les réseaux d'eau chaude conformes à und Wärmedämmung für Heißwasser-
l'EN 13941-1 Fernwärmenetze nach EN 13941-1
This European Standard was approved by CEN on 12 August 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 489-1:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Requirements . 6
5 Test methods . 9
6 Marking . 15
7 Reporting . 16
Annex A (normative) Overview of available joint casing systems . 18
Annex B (informative) Guidelines for inspection and testing . 23
Bibliography . 25
European foreword
This document (EN 489-1:2019) has been prepared by Technical Committee CEN/TC 107 “District
heating and cooling”, the secretariat of which is held by DS.
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 April 2020, and conflicting national standards shall be
withdrawn at the latest by April 2020.
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 489:2009.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Introduction
The first edition of EN 489 was approved in 1994 and updated in 2003 and 2009. The main areas of this
revision are the following:
— Terms and definitions has been moved to EN 13941-1;
— Ageing resistance test for PUR foam has been removed;
— requirements to plugs have been added;
— requirements and test methods for PUR foam properties are back in EN 253;
— requirements for marking of joints have been added;
— preparation of test specimen, under supervision of the test institute, has been added;
— it is valid for twin-pipe systems as well;
— Annex C was moved to EN 13941-2;
— concerning the soil stress test - the possibility of either overfill with 1 m sand or use of a rigid plate
was removed and is replaced by a total load of a rigid plate plus 0,3 m of sand to a total of 18 kN/m ;
— larger pipe diameters may be tested in soil stress test.
This specification 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 EN 253.
Other standards from TC 107 are:
— EN 253, District heating pipes — Bonded single pipe systems for buried hot water networks — Factory
made pipe assembly of a steel service pipe, polyurethane foam thermal insulation and a casing of
polyethylene;
— EN 448, District heating pipes — Bonded pipe systems for buried hot water networks — Factory made
fitting assemblies of steel service pipes, polyurethane thermal insulation and a casing of polyethylene;
— EN 488, District heating pipes — Bonded single pipe systems for directly buried hot water networks —
Factory made steel valve assembly for steel service pipes, polyurethane foam thermal insulation and a
casing of polyethylene;
— EN 13941-1, District heating pipes — Design and installation of thermal insulated bonded single and
twin pipe systems for buried hot water networks — Part 1: Design
— EN 13941-2, District heating pipes — Design and installation of thermal insulated bonded single and
twin pipe systems for buried hot water networks — Part 2: Installation
— EN 17248, District heating and district cooling pipe systems - Terms and definitions
— EN 14419, District heating pipes — Bonded single and twin pipe systems for directly buried hot water
networks — Surveillance systems.
— EN 15632 (all parts), District heating pipes - Pre-insulated flexible pipe systems
— EN 15698-1, District heating pipes — Bonded twin pipe systems for directly buried hot water networks
— Part 1: Factory made twin pipe assembly of steel service pipes, polyurethane foam thermal insulation
and one casing of polyethylene
— EN 15698-2, District heating pipes — Bonded twin pipe systems for directly buried hot water networks
— Part 2: Factory made fitting and valve assemblies of steel service pipes, polyurethane thermal
insulation and one casing of polyethylene
1 Scope
This document specifies requirements and test methods for joints between adjacent factory made pipe,
and/or fitting and/or valve assemblies for buried hot water networks in accordance with EN 13941-1.
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 253:2019, District heating pipes — Bonded single pipe systems for buried hot water networks — Factory
made pipe assembly of a steel service pipe, polyurethane foam thermal insulation and a casing of
polyethylene
EN 12814-1, Testing of welded joints of thermoplastics semi-finished products — Part 1: Bend test
EN 13941-2, District heating pipes — Design and installation of thermal insulated bonded single and twin
pipe systems for directly buried hot water networks — Part 2: Installation
EN 17248, District heating and district cooling pipe systems — Terms and definitions
EN 14419, District heating pipes — Bonded single and twin pipe systems for directly buried hot water
networks — Surveillance systems
ISO 16770, Plastics — Determination of environmental stress cracking (ESC) of polyethylene — Full-notch
creep test (FNCT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 17248 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 https://www.iso.org/obp
4 Requirements
4.1 General
Requirements which shall be fulfilled for all joints:

Under preparation. Stage at the time of publication: ISO/DIS 16770
Table 1 — Requirements to be tested on different systems
Joint requirements Welded joint Sealed joint
Soil stress if SCR is not possible 4.3.4
4.3.4
Stress Crack Resistance 4.3.6 -
SCR
Water tightness 4.3.5 4.3.5
Foam properties 4.3.3 4.3.3
Plug properties 4.3.7 4.3.7.2
4.2 General requirements for type testing
4.2.1 General
The assumptions of EN 13941-1 have been taken as the base for these requirements.
On testing each joint casing system and all relevant products shall be provided with installation
instructions, product data sheet and, if relevant, safety datasheet.
NOTE Annex A gives a categorization of different joint casing systems.
4.2.2 General requirements for the joint
The joint shall be:
— watertight;
— able to withstand longitudinal forces initiated by longitudinal movements of the pipe in the ground;
— able to withstand radial forces and bending moments;
— able to withstand effects of temperature and temperature variations.
4.2.3 Installation of the joint
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 joints of single and twin pipes
4.3.1 General
There are no differences in requirements for single and twin pipe joints.
4.3.2 Welding of steel service pipes
Welds between steel service pipes shall be made in conformance with EN 13941-2.
4.3.3 Polyurethane (PUR) foam thermal insulation
4.3.3.1 General
The installation of the on-site filled insulation or the pre-fabricated thermal joint insulation shall be
carried out according to the supplier’s installation instruction.
The insulation shall completely fill the joint.
4.3.3.2 Foam density
The requirement for foam density shall be in accordance with EN 253.
4.3.3.3 Compressive strength
The requirement for compressive strength shall be in accordance with EN 253.
4.3.3.4 Cell size
The requirement for the average cell size in radial direction shall be in accordance with EN 253.
4.3.3.5 Water absorption at elevated temperature
The requirement for water absorption at elevated temperature shall be in accordance with EN 253.
4.3.4 Soil stress test
Joints shall, as mentioned in Table 1, pass the soil stress test in accordance with 5.2.
4.3.5 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.
4.3.6 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 300 h.
If SCR test is not possible the soil stress test according to 5.2 shall be performed.
4.3.7 Plugs
4.3.7.1 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).
4.3.7.2 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. The definitions of single sealed, double sealed or multiple sealed are given in Annex A together
with the tests that shall be carried out.
4.3.7.3 Welded plugs
Welded plugs shall fulfil the requirement of the bending test in accordance with 5.7.
They shall be tested following the approach of the joint casing system in which they are used.
The bending test of the welded plug according to 5.7 is to be performed after the watertightness test
4.3.8 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, in g/10 min, 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 and for achieving the expected lifetime, 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;
b) environmental conditions for installation;
c) identification of components;
d) required installation equipment and tools;
e) proper procedures for the cleaning, drying and preparation of surfaces;
f) relevant test procedures for leak-tightness of joint shall be described;
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 testing.
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 specified before the assembly takes place. This specification
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 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 box
A box with minimum dimensions as shown in Figure 1 shall be used. The box shall be provided with a
rigid compression plate that covers the entire box.
Dimensions in millimetres
Key
1 Sand
2 joint casing
Figure 1 — Minimum dimensions of sand box
5.2.3 Sand for soil stress test
Natural sand in air-dried condition with a moisture content of maximum 0,5 % (mass fraction), at room
temperature with a grain distribution as shown in Figure 2 shall be used.

Key
x grain size in mm
y accumulated weight in %
Figure 2 — Grain size distribution of test sand
The sand within the sandbox shall be removed in its entirety, remixed and refilled for every specimen
tested.
Sand grain size distribution and moisture content shall be verified and reported for every test specimen.
5.2.4 Test specimens
Two test specimens of minimum length 2,5 m with a joint casing in the middle shall be used.
One test specimen shall be made of a pipe with casing diameter 160 mm and one specimen shall be made
of a pipe with casing diameter 250 mm. In case of a product which is available for a certain diameter
range, two specimens may be tested on two different diameters within this range.
a) 160 mm diameter pipe: sandbox and water tightness according Annex A.
b) 250 mm diameter pipe: sandbox and water tightness according Annex A.
5.2.5 Sand box test
The following test parameters shall be used:
— service pipe temperature of (120 ± 2) °C with a liquid maintained for 24 h before and during testing;
+100
— sand overfill of 300 mm, measured from the top of the casing pipe, plus a pressure with a rigid
plate up to a total of (18 ± 1) kN/m ; including the weight of the rigid plate;
+100
— the length from the end of the joint casing to the inside of the sand box wall shall be 500 mm;
— one rigid flat plate that covers the whole surface of the sand overfill with a max. gap of 50 mm on all
four sides. The plate shall not bend more than 3 mm/m;
— before positioning the rigid plate the sand shall be levelled horizontally with a tolerance of ± 20 mm;
— displacement of 75 ± 2 mm in continuous motion;
— pushing speed of 10 ± 1 mm/min;
— pulling speed of 50 ± 1 mm/min;
— 100 cycles, where a cycle is defined as one pushing (75 mm) and one pulling (75 mm) movement
without pause. A cycle starts with pushing;
— the pipe g
...