SIST EN 488-1:2025
(Main)District heating pipes - Bonded single pipe systems for directly buried hot water networks - Part 1: Factory made steel valve assembly for steel service pipes, polyurethane thermal insulation and a casing of polyethylene
District heating pipes - Bonded single pipe systems for directly buried hot water networks - Part 1: Factory made steel valve assembly for steel service pipes, polyurethane thermal insulation and a casing of polyethylene
This document specifies requirements and test methods for factory made thermally insulated bonded steel shut-off valve assemblies for hot water networks in accordance with EN 13941-1, comprising a steel valve, valve extension pipes, polyurethane (PUR) foam thermal insulation and a casing of polyethylene.
This document applies to steel valve assemblies with an internal pressure of maximum 2,5 MPa.
The principles of this document can be applied to thermal insulated bonded steel valve assemblies with internal pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure.
The steel shut-off valve assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
Fernwärmerohre - Einrohr-Verbundsysteme für direkt erdverlegte Fernwärmenetze - Teil 1: Werkmäßig gefertigte Stahlarmaturenbaueinheit für Stahl-Mediumrohre, Wärmedämmung aus Polyurethan und einer Ummantelung aus Polyethylen
Dieses Dokument legt die Anforderungen und Prüfverfahren für werkseitig hergestellte, wärmegedämmte Verbund Absperrarmaturbaueinheiten aus Stahl für Fernwärmenetze in Übereinstimmung mit EN 13941 1 fest, die aus einer Stahl-Armatur, Armatur-Verlängerungsrohren, einer Wärmedämmung aus Polyurethan-Schaum (PUR) und einer Ummantelung aus Polyethylen bestehen.
Dieses Dokument gilt für Absperrarmaturbaueinheiten aus Stahl mit einem Innendruck von höchstens 2,5 MPa.
Die in diesem Dokument dargelegten Grundsätze können auf wärmegedämmte Verbund-Armatur-baueinheiten aus Stahl mit einem Innendruck von mehr als 2,5 MPa angewendet werden, sofern den Auswirkungen des Drucks besondere Aufmerksamkeit geschenkt wird.
Die Absperrarmaturbaueinheit aus Stahl kann darüber hinaus die folgenden zusätzlichen Bauteile umfassen: Messdrähte, Abstandhalter und DiffusionsbarrierenN1).
Tuyaux de chauffage urbain - Systèmes bloqués monotubes pour les réseaux d'eau chaude enterrés directement - Partie 1 : Assemblages d'appareils de robinetterie en acier manufacturés pour tubes de service en acier, isolation thermique en polyuréthane et enveloppe en polyéthylène
Le présent document définit les exigences et les méthodes d’essais applicables aux assemblages d’appareils de robinetterie d'arrêt en acier manufacturés bloqués isolés thermiquement pour les réseaux d’eau chaude conformément à l’EN 13941-1, comprenant un appareil de robinetterie en acier, des tubes d’extension, une isolation thermique en mousse de polyuréthane (PUR) et une enveloppe en polyéthylène.
Le présent document s'applique aux assemblages d'appareils de robinetterie en acier avec une pression interne maximale de 2,5 MPa.
Les principes du présent document peuvent s'appliquer aux assemblages d'appareils de robinetterie en acier bloqués isolés thermiquement avec des pressions internes supérieures à 2,5 MPa, à condition qu'une attention particulière soit accordée aux effets de la pression.
L’assemblage d’appareils de robinetterie d'arrêt en acier peut également comprendre les éléments supplémentaires suivants : câbles de mesure, entretoises et barrières anti-diffusion.
Cevi za daljinsko ogrevanje - Poviti enocevni sistemi za neposredno vkopana vročevodna omrežja - 1. del: Tovarniško izdelan sestav jeklenih ventilov za jeklene delovne cevi, obdane s poliuretansko toplotno izolacijo in zaščitnim plaščem iz polietilena
Ta dokument določa zahteve in preskusne metode za tovarniško izdelane toplotno izolirane sestave povitih jeklenih zapornih ventilov za vročevodna omrežja v skladu s standardom EN 13941-1, ki so sestavljeni iz jeklenih ventilov, podaljškov za ventile, poliuretanske (PUR) toplotne izolacije in zaščitnega plašča iz polietilena (PE). Ta dokument se uporablja za sestave jeklenih ventilov z največjim notranjim tlakom 2,5 MPa. Načela tega dokumenta je mogoče uporabljati za toplotno izolirane sestave povitih jeklenih ventilov z notranjimi tlaki, višjimi od 2,5 MPa, če je posebna pozornost namenjena učinkom tlaka. Sestav jeklenih zapornih ventilov lahko vključuje tudi naslednje dodatne elemente: merilne žice, distančnike in difuzijske pregrade.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2025
Cevi za daljinsko ogrevanje - Poviti enocevni sistemi za neposredno vkopana
vročevodna omrežja - 1. del: Tovarniško izdelan sestav jeklenih ventilov za jeklene
delovne cevi, obdane s poliuretansko toplotno izolacijo in zaščitnim plaščem iz
polietilena
District heating pipes - Bonded single pipe systems for directly buried hot water networks
- Part 1: Factory made steel valve assembly for steel service pipes, polyurethane thermal
insulation and a casing of polyethylene
Fernwärmerohre - Einrohr-Verbundsysteme für direkt erdverlegte Fernwärmenetze - Teil
1: Werkmäßig gefertigte Stahlarmaturenbaueinheit für Stahl-Mediumrohre,
Wärmedämmung aus Polyurethan und einer Ummantelung aus Polyethylen
Tuyaux de chauffage urbain - Systèmes bloqués monotubes pour les réseaux d'eau
chaude enterrés directement - Partie 1 : Assemblages d'appareils de robinetterie en
acier manufacturés pour tubes de service en acier, isolation thermique en polyuréthane
et enveloppe en polyéthylène
Ta slovenski standard je istoveten z: EN 488-1:2025
ICS:
23.040.07 Cevovodi za daljinsko Pipeline and its parts for
ogrevanje in njihovi deli district heat
23.060.01 Ventili na splošno Valves in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 488-1
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 23.060.01; 23.040.07 Supersedes EN 488:2019
English Version
District heating pipes - Bonded single pipe systems for
directly buried hot water networks - Part 1: Factory made
steel shut-off valve assembly for steel service pipes,
polyurethane thermal insulation and a casing of
polyethylene
Tuyaux de chauffage urbain - Systèmes bloqués Fernwärmerohre - Einrohr-Verbundsysteme für direkt
monotubes pour les réseaux d'eau chaude enterrés erdverlegte Fernwärmenetze - Teil 1: Werkmäßig
directement - Partie 1 : Assemblage d'appareils de gefertigte Stahlabsperrarmaturenbaueinheit für Stahl-
robinetterie d'arrêt en acier manufacturés pour tubes Mediumrohre, Wärmedämmung aus Polyurethan und
de service en acier, isolation thermique en einer Ummantelung aus Polyethylen
polyuréthane et enveloppe en polyéthylène
This European Standard was approved by CEN on 27 January 2025.
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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 488-1:2025 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 . 7
4.1 General . 7
4.2 Pressure ratings for valves . 7
4.2.1 General . 7
4.2.2 Valves without indicated flow direction . 7
4.3 Service temperatures for valves . 7
4.4 Steel parts . 7
4.4.1 Specification . 7
4.4.2 Valve. 7
4.4.3 Valve extension pipes . 8
4.4.4 Surface condition . 8
4.4.5 Welding of steel parts . 8
4.5 Casing . 8
4.6 Polyurethane foam thermal insulation . 8
4.6.1 General . 8
4.6.2 Minimum thickness of thermal insulation . 8
4.7 Valve assembly . 8
4.7.1 General . 8
4.7.2 Thermal insulation series . 8
4.7.3 Ends of valve assembly . 8
4.7.4 Polyethylene welding . 9
4.7.5 End of stem construction . 9
4.7.6 Tolerances of main dimensions .10
4.7.7 Expected thermal life and long term temperature resistance .10
4.7.8 Thermal conductivity .10
4.7.9 Surface conditions at delivery .10
4.7.10 Measuring wires for surveillance systems .10
4.8 Installation, operation and maintenance .10
4.8.1 Installation .10
4.8.2 Operation .10
4.8.3 Maintenance .11
4.9 Resistance to axial forces and bending moments.11
5 Test methods .11
5.1 General conditions and test specimens .11
5.2 Test specimens .11
5.2.1 Type testing of steel parts of the valve .11
5.2.2 Test specimens from casings and polyurethane foam thermal insulation .12
5.3 Steel parts .12
5.3.1 Type test of the steel parts .12
5.3.2 Production testing of valves .15
6 Marking . 16
6.1 General . 16
6.2 Valve . 16
6.3 Valve extension pipes. 16
6.4 Casing . 16
6.5 Valve assembly . 16
Annex A (informative) Guidelines for inspection and testing . 18
Annex B (normative) Resistance to axial force and bending moment . 20
Annex C (normative) Resistance to bending forces . 22
Annex D (informative) Waste treatment and recycling . 27
Bibliography . 28
European foreword
This document (EN 488-1:2025) has been prepared by Technical Committee CEN/TC 107 “District
heating and cooling systems”, 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 September 2025, and conflicting national standards shall
be withdrawn at the latest by September 2025.
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 488:2019.
— alignment with the structure of EN 253;
— the valves shall be designed for an operating pressure of 2,5 MPa in accordance with 4.2.1;
— the requirements for the valve extension pipes are specified in 4.4.3;
— for the leak-tightness of the seat of the unloaded steel valves up to DN 400, a distinction is no longer
made between different leakage rates, see 5.3.1.3;
— added requirement: Before measuring the torque, the valve shall be closed for 24 h, see 5.3.1.4;
— when marking the valve assemblies, information about the diffusion barrier is also to be provided,
see 6.5.
The EN 488 series is currently composed of the following parts:
— EN 488-1, District heating pipes – Bonded single pipe systems for directly buried hot water networks –
Part 1: Factory made steel shut-off valve assembly for steel service pipes, polyurethane thermal
insulation and a casing of polyethylene (this document);
— EN 488-2, District heating and district cooling pipes – Bonded pipe systems for directly buried hot and
cold water networks – Part 2: Factory made steel service valve assembly for steel service pipes,
polyurethane thermal insulation and a casing of polyethylene.
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.
Introduction
Other standards from CEN/TC 107 are:
— 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 448, District heating pipes — Bonded single pipe systems for directly buried hot water networks —
Factory made fitting assemblies of steel service pipes, polyurethane thermal insulation and a casing of
polyethylene
— EN 488-2, District heating and district cooling pipes — Bonded pipe systems for directly buried hot and
cold water networks — Part 2: Factory made steel valve assembly for draining and venting,
polyurethane thermal insulation and a casing of polyethylene
— EN 489-1, 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
— EN 13941-1, District heating pipes — Design and installation of thermal insulated bonded single and
twin pipe systems for directly 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 directly buried hot water networks — Part 2: Installation
— EN 14419, District heating pipes — Bonded single and twin pipe systems for buried hot water networks
— Surveillance systems
— EN 15632 (all parts), District heating pipes — Factory made 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 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
— EN 17248, District heating and district cooling pipe systems — Terms and definitions
— EN 17414 (all parts), District cooling pipes — Factory made flexible pipe systems
— EN 17415 (all parts), District cooling pipes — Bonded single pipe systems for directly buried cold water
networks
— EN 17878 (all parts), District heating pipes — Factory made flexible pipe systems with a lower
temperature profile
Waste management and recycling of materials is dealt with in Annex D.
1 Scope
This document specifies requirements and test methods for factory made thermally insulated bonded
steel shut-off valve assemblies for hot water networks in accordance with EN 13941-1, comprising a steel
valve, valve extension pipes, polyurethane (PUR) foam thermal insulation and a casing of polyethylene.
This document applies to steel valve assemblies with an internal pressure of maximum 2,5 MPa.
The principles of this document can be applied to thermal insulated bonded steel valve assemblies with
internal pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure.
The steel shut-off valve assembly can also include the following additional elements: measuring wires,
spacers and diffusion barriers.
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 19, Industrial valves — Marking of metallic valves
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 448, District heating pipes — Bonded single pipe systems for directly buried hot water networks —
Factory made fitting assemblies of steel service pipes, polyurethane thermal insulation and a casing of
polyethylene
EN 736-1, Valves — Terminology — Part 1: Definition of types of valves
EN 736-3, Valves — Terminology — Part 3: Definition of terms
EN 10204, Metallic products — Types of inspection documents
EN 12266-1, Industrial valves — Testing of metallic valves — Part 1: Pressure tests, test procedures and
acceptance criteria — Mandatory requirements
EN 13941-1, District heating pipes — Design and installation of thermal insulated bonded single and twin
pipe systems for directly buried hot water networks — Part 1: Design
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 definitions given in EN 736-1, EN 736-3 and EN 17248
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
4 Requirements
4.1 General
Unless otherwise specified, the requirements shall be valid for each single measurement.
For information on suitable guidelines for inspection and testing see Annex A.
For reasons of readability, the term shut-off steel valve is referred to in the following text as (steel) valve.
4.2 Pressure ratings for valves
4.2.1 General
The valves shall be designed for use in pipe systems with a maximum internal pressure of 2,5 MPa.
NOTE For pressure testing of the pipe systems, see EN 13941-2.
4.2.2 Valves without indicated flow direction
Valves without an indicated flow direction shall support the pressure load in both directions.
4.3 Service temperatures for valves
The valves shall be able to withstand continuous operation with hot water at various temperatures in
accordance with EN 13941-1 and at a minimum water temperature of 1 °C.
The p/T-rating of the manufacturer shall be considered.
4.4 Steel parts
4.4.1 Specification
Steel grades are specified in EN 13941-1.
All valves, valve extension pipes and steel components used for manufacturing of valve assemblies under
the scope of this document shall as a minimum be delivered to the manufacturer with an inspection
certificate 3.1 according to EN 10204. The inspection certificate shall on request be passed on to the
customer.
In case a material related inspection certificate 3.1 according to EN 10204 is required by the customer
who orders the valve assembly, this request shall be given whilst placing the order with the manufacturer
of the valve assemblies.
Any later request for provision of such documentation could be too late and possibly can't be met by the
manufacturer, since the manufacturer organizes the assignment of inspection certificates 3.1 to the steel
extension pipes and shell of the valves before starting the production.
NOTE For cold-formed valve bodies, the material inspection certificates 3.1 according to EN 10204 apply to
the values of the chemical composition, but not to the values of the mechanical properties.
All components shall be designed in accordance with EN 13941-1, for the actions and stresses that
normally occur during the service life of the valve assembly (or of the component).
4.4.2 Valve
The shell of the valve shall be fully welded. Detachable joints, such as flanged or screwed connections,
except sealing system at the stem, shall not be used in the pressurized area.
The quality of the shell of the valve shall match with the quality of the valve extension pipe.
4.4.3 Valve extension pipes
Subject to design considerations other wall thicknesses than those given in EN 253 may be used, but in
no case shall these be less than the minima indicated in EN 253.
The nominal diameter, the outside diameter, the tolerances on the diameter of the pipe ends and the wall
thickness shall be the same as for the service pipes in accordance with EN 253.
4.4.4 Surface condition
The surface conditions of the steel service pipe and the valve body shall be in accordance with EN 253.
4.4.5 Welding of steel parts
Fusion welding between the valve and the valve extension pipes also as the pressurized parts of the valve
shall be carried out in accordance with EN 448.
4.5 Casing
Material and casing properties shall be as specified in EN 253.
The polyethylene welding shall be in accordance with EN 448.
4.6 Polyurethane foam thermal insulation
4.6.1 General
The PUR shall be in accordance with EN 253.
Test specimens from fitting assemblies to establish foam properties shall be taken in accordance with
EN 448.
4.6.2 Minimum thickness of thermal insulation
The minimum thickness of polyurethane foam thermal insulation shall be in accordance with EN 448.
4.7 Valve assembly
4.7.1 General
All requirements are valid including the diffusion barrier, if any.
4.7.2 Thermal insulation series
The thermal insulation series shall be in accordance with EN 253.
The minimum thickness of the polyurethane (PUR) foam thermal insulation shall be in accordance with
EN 448.
4.7.3 Ends of valve assembly
4.7.3.1 Pipe ends without thermal insulation
The ends of the extension pipes shall be free from insulation according to EN 253.
The ends of the extension pipes shall be prepared for welding according to EN 448.
4.7.3.2 Diameter and wall thickness of the casing
The outside diameter and the minimum wall thickness after manufacturing of the valve assemblies shall
be in accordance with EN 253.
4.7.3.3 Centre line deviation
The distance between the centre lines of the valve extension pipes and the casing at the ends of the valve
assembly shall not exceed the limits given in EN 253.
The centre line deviation shall be measured between the centre lines with the largest deviation.
4.7.3.4 Angular deviation between valve extension pipes and casing
The angular deviation between the centre lines of the of the valve extension pipes and the casing shall
not exceed the limits given in EN 448.
The angular deviation shall be measured between the centre lines at the welding end of the valve
assembly.
4.7.3.5 Minimum length of casing
The length of the casing at the ends of the valve assembly shall not be less than the limit given in EN 448.
4.7.4 Polyethylene welding
The polyethylene welding shall be in accordance with EN 448.
4.7.5 End of stem construction
To ensure a long service life of the end stem passing through the shrinking sealing, the end of stem
construction shall withstand the aggressive underground condition such as heat, cold, moisture, ground
and salty water. Where the stem construction passes the casing there shall be an arrangement to protect
against water ingress to the thermal insulation.
The following properties shall be ensured and considered:
— The stem construction outside the thermal insulation shall be made from stainless steel with at least
16 % of chromium. Factors influencing the corrosion probability of the stainless steel construction can
be assessed according to EN 12502-4.
— Specifically used steel type is documented by appropriate quality management system;
— Under specific installation and operation conditions a chrome content of 16 % alone might not be
sufficient, so that other alloy elements are then recommended.
The protection by corrosion resistant material shall be added at the length of at least 100 mm from the
top of the ‘stem house’, see Figure 1.
Key
L length
H height offset
1 minimum length for corrosion resistant material (100 mm)
2 shrinking sealing
Figure 1 — Main dimensions and corrosion protection
4.7.6 Tolerances of main dimensions
The main dimensions of the valve assembly H and L are shown in Figure 1. The values of L and H shall be
declared by the manufacturer. The tolerances of H and L shall be in accordance with Table 1.
Table 1 — Toleranc
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