EN 13941-1:2019+A1:2021
(Main + Amendment)District heating pipes - Design and installation of thermal insulated bonded single and twin pipe systems for directly buried hot water networks - Part 1: Design
General Information
- Abstract
This European Standard specifies requirements for design, calculation and installation of factory made thermal insulated bonded single and twin pipe systems for directly buried hot water networks for continuous operation with treated hot water at various temperatures up to 120 ºC and occasionally with peak temperatures up to 140 ºC and maximum internal pressure 2,5 MPa. Flexible pipe systems according to EN 15632 are not under the scope of this standard.
The standard EN 13941, Design and installation of thermal insulated bonded single and twin pipe systems for directly buried hot water networks consists of two parts:
a) prEN 13941-1: Design;
b) prEN 13941-2: Installation.
The requirements and stipulations in this part: EN 13941-1, form an unbreakable unity with those of prEN 13941-2. This part shall therefore exclusively be used in combination with prEN 13941-2.
The principles of the standard may be applied to thermal insulated pipe systems with pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure.
Adjacent pipes, not buried, but belonging to the network (e. g. pipes in ducts, valve chambers, road crossings above ground etc.) may be designed and installed according to this standard.
This standard presupposes the use of treated water, which by softening, demineralisation, de-aeration, adding of chemicals, or otherwise has been treated to effectively prevent internal corrosion and deposits in the pipes.
NOTE For further information on water qualities to be used in district heating pipe systems see also [1].
This standard is not applicable for such units as:
a) pumps;
b) heat exchangers;
c) boilers, tanks;
d) systems behind domestic substations.
- Status
- Published
- Publication Date
- 14-Dec-2021
- Withdrawal Date
- 29-Jun-2022
- Technical Committee
- CEN/TC 107 - Pre-fabricated district heating pipe systems
- Drafting Committee
- CEN/TC 107 - Pre-fabricated district heating pipe systems
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 16-Jan-2025
- Completion Date
- 17-Sep-2026
Overview
EN 13941-1:2019+A1:2021 (EN 13941-1) is the European design standard for thermal insulated bonded single and twin pipe systems used in directly buried hot water district heating networks. It sets requirements for design, calculation and related installation provisions for factory-made bonded pipe assemblies intended for continuous operation with treated hot water up to 120 °C (occasional peaks to 140 °C) and a maximum internal pressure of 2.5 MPa. This Part 1 (Design) is intended to be used together with Part 2 (Installation); the two parts form an integral whole.
Key topics and technical requirements
- Scope and exclusions: Applies to bonded single/twin pipes for buried networks; excludes flexible systems covered by EN 15632 and equipment such as pumps, heat exchangers, boilers, tanks and systems behind domestic substations.
- Materials & components: Requirements for steel service pipes, polyurethane (PUR) foam insulation, outer casings, field joint materials, valves, expansion cushions and markings.
- Design & calculations: Procedures for global analysis, cross‑sectional stresses, deflection, bends, T‑pieces, reducers and compensators; determination of stresses, strains and fatigue.
- Pipe–soil interaction: Detailed modelling of axial friction, lateral soil reaction, combined stiffness of steel/PUR/soil, settlement and soft soil provisions.
- Actions & loads: Temperature variations, top soil loads, traffic loads, and load combinations relevant for buried networks.
- Limit states & service life: Serviceability, plastic deformation, fatigue, instability and compressive/shear limits for materials (steel, PUR, PE).
- Project planning & QA: Risk assessment, project classes, route selection, minimum distances, venting/draining, procurement, quality control and required design documentation.
Practical applications & users
This standard is essential for:
- District heating designers and civil/mechanical engineers preparing pipe system specifications and stress analyses.
- Pipe and fittings manufacturers producing factory‑made bonded assemblies and documentation.
- Construction contractors and installers responsible for buried pipeline alignment, jointing and QA (in conjunction with EN 13941-2).
- Network owners, asset managers and authorities specifying performance, service life and inspection criteria. Use cases include design of new hot water distribution mains, pipeline replacements, road crossings, valve chambers and above‑ground sections belonging to the network.
Related standards (if applicable)
- EN 13941-2 - Installation (must be used together with EN 13941-1)
- EN 15632 - Flexible pipe systems (outside scope)
- National codes and water‑quality guidance referenced in the standard for treated water requirements
Keywords: district heating pipes, thermal insulated bonded pipe systems, directly buried hot water networks, EN 13941-1, pipeline design, pipe-soil interaction, polyurethane insulated pipes, buried hot water networks.
Relations
- Effective Date
- 19-Jan-2023
- Effective Date
- 19-Jan-2023
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
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Frequently Asked Questions
EN 13941-1:2019+A1:2021 is a standard published by the European Committee for Standardization (CEN). Its full title is "District heating pipes - Design and installation of thermal insulated bonded single and twin pipe systems for directly buried hot water networks - Part 1: Design". This standard covers: This European Standard specifies requirements for design, calculation and installation of factory made thermal insulated bonded single and twin pipe systems for directly buried hot water networks for continuous operation with treated hot water at various temperatures up to 120 ºC and occasionally with peak temperatures up to 140 ºC and maximum internal pressure 2,5 MPa. Flexible pipe systems according to EN 15632 are not under the scope of this standard. The standard EN 13941, Design and installation of thermal insulated bonded single and twin pipe systems for directly buried hot water networks consists of two parts: a) prEN 13941-1: Design; b) prEN 13941-2: Installation. The requirements and stipulations in this part: EN 13941-1, form an unbreakable unity with those of prEN 13941-2. This part shall therefore exclusively be used in combination with prEN 13941-2. The principles of the standard may be applied to thermal insulated pipe systems with pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure. Adjacent pipes, not buried, but belonging to the network (e. g. pipes in ducts, valve chambers, road crossings above ground etc.) may be designed and installed according to this standard. This standard presupposes the use of treated water, which by softening, demineralisation, de-aeration, adding of chemicals, or otherwise has been treated to effectively prevent internal corrosion and deposits in the pipes. NOTE For further information on water qualities to be used in district heating pipe systems see also [1]. This standard is not applicable for such units as: a) pumps; b) heat exchangers; c) boilers, tanks; d) systems behind domestic substations.
This European Standard specifies requirements for design, calculation and installation of factory made thermal insulated bonded single and twin pipe systems for directly buried hot water networks for continuous operation with treated hot water at various temperatures up to 120 ºC and occasionally with peak temperatures up to 140 ºC and maximum internal pressure 2,5 MPa. Flexible pipe systems according to EN 15632 are not under the scope of this standard. The standard EN 13941, Design and installation of thermal insulated bonded single and twin pipe systems for directly buried hot water networks consists of two parts: a) prEN 13941-1: Design; b) prEN 13941-2: Installation. The requirements and stipulations in this part: EN 13941-1, form an unbreakable unity with those of prEN 13941-2. This part shall therefore exclusively be used in combination with prEN 13941-2. The principles of the standard may be applied to thermal insulated pipe systems with pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure. Adjacent pipes, not buried, but belonging to the network (e. g. pipes in ducts, valve chambers, road crossings above ground etc.) may be designed and installed according to this standard. This standard presupposes the use of treated water, which by softening, demineralisation, de-aeration, adding of chemicals, or otherwise has been treated to effectively prevent internal corrosion and deposits in the pipes. NOTE For further information on water qualities to be used in district heating pipe systems see also [1]. This standard is not applicable for such units as: a) pumps; b) heat exchangers; c) boilers, tanks; d) systems behind domestic substations.
EN 13941-1:2019+A1:2021 is classified under the following ICS (International Classification for Standards) categories: 23.040.07 - Pipeline and its parts for district heat; 23.040.10 - Iron and steel pipes; 91.140.10 - Central heating systems. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 13941-1:2019+A1:2021 has the following relationships with other standards: It is inter standard links to EN 13941-1:2019/prA1, EN 13941-1:2019, EN 13480-3:2024, EN 17248:2019, EN 15698-2:2025, EN ISO 1856:2018, EN 10216-2:2024, EN 10253-2:2021+A1:2025, EN 14419:2019, EN 10217-2:2019, EN 253:2019+A1:2023, EN 10204:2004, EN 13941-2:2019+A1:2021, EN 489-1:2019, EN 15698-1:2025. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
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