CEN/TC 107 - Pre-fabricated district heating pipe systems

This document specifies classification, general requirements and test methods for flexible, factory made, buried district heating pipe systems.
This document is intended to be used only in conjunction with EN 17878-2 or EN 17878-3, as applicable.
This document is applicable to a maximum operating temperature of 80 °C and a maximum operating design pressure up to 1,0 MPa.
The pipe systems are designed for a service life of at least 50 years. For pipe systems with plastic service pipes, the respective temperature profiles are specified in EN 17878-2:2024 and EN 17878-3:2024.
For the transport of other liquids, for example potable water, additional requirements can be applicable.

This document specifies requirements and test methods for flexible, factory made, buried district heating pipe systems with plastic service pipes and bonding between the layers of the pipe assemblies.
It is only applicable in conjunction with EN 17878-1.
This document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district heating installations.
This document is applicable to a maximum operating temperature of 80 °C and maximum operating design pressure up to 1,0 MPa for a design service life of at least 50 years.
This document does not apply to cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing are needed. Such requirements are not specified in this document.

This document specifies requirements and test methods for flexible, factory made, buried district heating pipe systems with plastic service pipes and no bonding between the layers of the pipe assemblies.
It is only applicable in conjunction with EN 17878-1.
This document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district heating installations.
This document is applicable to a maximum operating temperature of 80 °C and maximum operating design pressure up to 1,0 MPa for a design service life of at least 50 years.
This document does not apply to cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing are needed. Such requirements are not specified in this document.

This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded single pipe assemblies for hot water networks in accordance with EN 13941-1, comprising a steel service pipe, polyurethane foam thermal insulation and a casing of polyethylene.
The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.

This document specifies requirements and test methods for flexible, factory made, buried district heating pipe systems with plastic service pipes and bonding between the layers of the pipe assemblies.
It is only applicable in conjunction with part 1.
This document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district heating installations.
This document is applicable to a maximum operating temperature of 95 °C and maximum operating design pressure up to 1,0 MPa for a design service life of at least 30 years.
This document does not apply to cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this document.

This document specifies classification, general requirements and test methods for flexible, factory made, buried district heating pipe systems.
This document is intended to be used in conjunction with part 2, 3 or 4, as applicable.
Depending on the pipe assembly (see Table 4), this document is applicable to a maximum operating temperature of 95 °C (part 2 and 3) and a maximum operating temperature of 120 °C (for part 4) and design pressures of 0,6 MPa to 2,5 MPa.
The pipe systems are designed for a service life of at least 30 years. For pipe systems with plastic service pipes, the respective temperature profiles are specified in EN 15632-2 and EN 15632-3.
NOTE   For the transport of other liquids, for example potable water, additional requirements can be applicable.

This document specifies requirements and test methods for flexible, factory made, buried district heating pipe systems with plastic service pipes and no bonding between the layers of the pipe assemblies.
It is only applicable in conjunction with part 1.
This document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district heating installations.
This document is applicable to a maximum operating temperature of 95 °C and maximum operating design pressure up to 1,0 MPa for a design service life of at least 30 years.
This document does not apply to cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this document.

This document specifies requirements and test methods for flexible, factory made, buried district heating pipe systems with metallic service pipes and bonding between the layers of the pipe assemblies and thermal insulation materials of polyurethane or polyisocyanurate foam, the casing being made of polyethylene.
It is only applicable in conjunction with part 1.
This document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district heating installations.
This document is applicable to a continuous operating temperature up to 120 °C and a maximum operating temperature of 140 °C for maximum 300 h/a, and a design pressure up to 2,5 MPa for a design service life of at least 30 years.
This document does not apply to cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this document.

This European Standard specifies requirements for design, calculation and installation of factory made thermal insulated bonded single and twin pipe systems for directly buried 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)   EN 13941-1: Design;
b)   EN 13941-2: Installation.
The requirements and stipulations in this part: prEN 13941-2, form an unbreakable unity with those of prEN 13941-1. This part shall therefore exclusively be used in combination with prEN 13941-1.
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.
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.

This document specifies requirements, design and test methods for factory made thermally insulated bonded valve assemblies for directly buried district cooling distribution systems, comprising a steel valve from DN 15 to DN 1200, rigid polyurethane foam insulation and a casing of polyethylene.
The valve assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document applies only to insulated valve assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar.
The design is based on an expected service life with continuous operation of a minimum 50 years.
NOTE   An expected service life of 50 years presupposes that treated water is used.

This document specifies requirements, design and test methods for factory made thermally insulated bonded fitting assemblies for directly buried district cooling distribution systems, comprising a service fitting from DN 15 to DN 1200, rigid polyurethane foam insulation and a casing of polyethylene.
The fitting assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document covers the following fitting assemblies: bend, tee, reducer, cap and anchor.
This document applies only to insulated fitting assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar.
The design is based on an expected service life with continuous operation of a minimum 50 years.
NOTE   An expected service life of 50 years presupposes that treated water is used.

This document specifies requirements, design and test methods for straight lengths of factory made thermally insulated pipe-in-pipe assemblies for directly buried district cooling distribution systems, comprising a service pipe from DN 15 to DN 1200, rigid polyurethane foam insulation and a casing of polyethylene. The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document applies only to insulated pipe assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar.
The design is based on an expected service life with continuous operation of a minimum 50 years.

This document specifies requirements and test methods for factory made thermally insulated bonded flexible pipe-in-pipe assemblies for directly buried district cooling distribution systems, comprising a service pipe and a casing of polyethylene. The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document is intended to be used in conjunction with EN 17414 1.
This document applies only to insulated pipe assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar dependent on material specified.
The design is based on an expected service life with continuous operation of a minimum 50 years.
This document does not cover surveillance systems.
In conjunction with the other parts of EN 17414, this document is applicable to pipes, fittings, their joints and to joints with components made of non-plastics materials intended to be used for district cooling installations.
NOTE   For the transport of other liquids, for example potable water, additional requirements could be applicable.

This document specifies requirements and test methods for factory made thermally insulated flexible pipe-in-pipe assemblies for directly buried district cooling distribution systems, comprising a service pipe and a casing of polyethylene. The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document is intended to be used in conjunction with EN 17414‑2 or EN 17414‑3.
This document applies only to insulated pipe assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar dependent on material specified.
The design is based on an expected service life with continuous operation of a minimum 50 years. For pipe systems with plastic service pipes, the respective temperature profiles are defined in EN 17414‑2 and EN 17414‑3.
NOTE For the transport of other liquids, for example potable water, additional requirements could be applicable.

This document specifies requirements and test methods for factory made thermally insulated non bonded flexible pipe-in-pipe assemblies for directly buried district cooling distribution systems, comprising a service pipe from DN 15 to DN 200 and a casing of polyethylene. The pipe assembly may also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document is intended to be used in conjunction with prEN 17414-1 ).
This document applies only to insulated pipe assemblies, for continuous operation with water at various temperatures (1 to 30) °C and a maximum operation pressure of 25 bar dependent on material specified.
The design is based on an expected service life with continuous operation of a minimum 50 years.
This document does not cover surveillance systems.
NOTE   For the transport of other liquids, for example potable water, additional requirements may be applicable.

This document specifies requirements and test methods for fittings of factory made thermally insulated bonded twin pipe assemblies for hot water networks in accordance with EN 13941 1, comprising two steel service fittings and/or valves, polyurethane foam thermal insulation and one casing of polyethylene.
The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document covers the following assemblies:
-   fittings: bends, T-pieces and reducers;
-   valve construction.
This document applies to fitting and valve assemblies with a minimum design pressure of 1,6 MPa (overpressure).

This document specifies requirements and test methods for surveillance systems for directly buried hot water networks in accordance with EN 13941 1 and EN 13941 2.
This document specifies requirements for the manufacture of measuring elements, for the manufacture of factory made bonded pipe, fitting and valve assemblies with measuring elements as well as for the assembly of the measuring elements in the field.
All requirements and recommendations described in this document are based on the experience gained with existing surveillance systems and their principle function.
The specific requirements given are only valid for electrical wire based surveillance systems forming an integral part of the pipes, valves, fittings and joints.

This document specifies requirements and test methods for factory made thermally insulated bonded valve assemblies for hot water networks in accordance with EN 13941 1, comprising a steel valve, rigid polyurethane foam thermal insulation and a casing of polyethylene.
The valve assembly could also include the following additional elements: measuring wires, spacers and diffusion barriers.

This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded twin pipe assemblies for directly buried hot water networks in accordance with EN 13941 1, comprising two steel service pipes, rigid polyurethane foam thermal insulation and one casing of polyethylene.
The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.

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.

This document compiles a vocabulary of terms, with their definitions, applied in the field of district heating and district cooling pipe systems with factory made system components. Only terms which are particular to the pertinent field in CEN/TC 107 are included.

This document specifies requirements and test methods for factory made thermally insulated bonded fitting assemblies for hot water networks in accordance with EN 13941 1, comprising a steel service fitting, rigid polyurethane foam thermal insulation and a casing of polyethylene.
The fitting assembly could also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document covers the following fitting assemblies: bend, tee, reducer, single use compensator and anchor.
This document applies to fitting assemblies with a minimum design pressure of 1,6 MPa (overpressure).

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.

This document specifies requirements and test methods for fitting and steel valve assemblies of factory made thermally insulated bonded twin pipe assemblies for hot water networks in accordance with EN 13941-1, comprising two steel service pipes, in most cases steel fittings and/or steel valves, steel components, polyurethane (PUR) foam thermal insulation and one casing of polyethylene.
NOTE   Steel components can be e.g. fixing bars.
The twin pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document covers the following assemblies:
-   fittings: bends, T-pieces and reducers;
-   valves for main line.
This document applies to fitting assemblies with an internal pressure of at least 1,6 MPa and steel valve assemblies with a maximum internal pressure of 2,5 MPa.

This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded twin pipe assemblies for directly buried hot water networks in accordance with EN 13941-1, comprising two steel service pipes, polyurethane (PUR) foam thermal insulation and a casing of polyethylene.
The twin pipe assembly can also include the following additional elements: Measuring wires, spacers and diffusion barriers.

This document specifies requirements for factory made thermally insulated bonded steel service valve assemblies for filling, draining, venting and operation purposes for directly buried hot and cold water networks in accordance with EN 13941-1, comprising a steel service valve, steel service pipe, polyurethane (PUR) foam thermal insulation and a casing of polyethylene (PE).
This document applies of steel service valve assemblies with an internal pressure of maximum 2,5 MPa.
The principles of this document can be applied to thermal insulated bonded steel service valve assemblies with internal pressures higher than 2,5 MPa, provided that special attention is paid to the effects of pressure.
The steel service valve assembly can also include the following additional elements: measuring wires, spacers, and diffusion barriers.

This document specifies requirements and test methods for factory made thermally insulated bonded fitting assemblies for hot water networks in accordance with EN 13941-1, comprising a steel service pipe, in most cases a steel fitting, polyurethane (PUR) foam thermal insulation and a casing of polyethylene.
The fitting assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.
This document specifies the characteristics of the following fitting assemblies:
-   bends, T-pieces, and reducers.
This document applies to fitting assemblies with a design pressure of at least 1,6 MPa.

This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded single pipe assemblies for hot water networks in accordance with EN 13941-1, comprising a steel service pipe, polyurethane foam thermal insulation and a casing of polyethylene.
The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.

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 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)   EN 13941-1: Design;
b)   EN 13941-2: Installation.
The requirements and stipulations in this part: prEN 13941-2, form an unbreakable unity with those of prEN 13941-1. This part shall therefore exclusively be used in combination with prEN 13941-1.
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.
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 and test methods for straight lengths of prefabricated thermally insulated pipe-in-pipe assemblies for directly buried hot water networks, comprising a steel service pipe from DN 15 to DN 1200, rigid polyurethane foam insulation and an outer casing of polyethylene. The pipe assembly may also include the following additional elements: measuring wires, spacers and diffusion barriers.
This standard applies only to insulated pipe assemblies, for continuous operation with hot water at various temperatures up to 120 °C and occasionally with a peak temperature up to 140 °C.
The estimation of expected thermal life with continuous operation at various temperatures is outlined in Annex B.

This European Standard specifies rules for design, calculation and installation for preinsulated bonded pipe systems for buried hot water distribution and transmission networks (cf. figure 2) with pipe assemblies in accordance with EN 253, for continuous operation with hot water at various temperatures up to 120ºC and occasionally with peak temperatures up to 140ºC and maximum internal pressure 25 bar (overpressure).
Application rule:
For larger pipe dimensions and pressures below 25 bar wall thickness bigger than specified in EN 253 can be required for straight pipes, bends and tees.
The principles of the standard can be applied to preinsulated pipe systems with pressures higher than 25 bar, provided that special attention is paid to the effects of pressure. Adjacent pipes belonging to the network (e.g. pipes in ducts, valve chambers, road crossings above ground etc.) can be designed and installed according to this standard.
The standard assumes use of treated water, which by softening, demineralisation, deaeration, adding of chemicals, or otherwise has been treated to prevent internal corrosion and deposits in the pipes.
This standard is not applicable for such units as:
a) pumps,
b) exchangers,
c) boiler installations, tank installations,
d) consumer installations.
However, the full functional ability and durability of such units should be ensured in consideration of the impacts from the district heating system and other impacts occurring from the conditions under which they have been installed.
Guidelines for product quality inspection and in situ tests of joints are given in Annex A of EN 448:2009, Annex D of EN 253:2009, Annex A of EN 488:2009 and Annex B of EN 489:2009.
Guidelines for welding of polyethylene casing are given in Annex B of EN 448:2009.
The estimation of expected life with continuous operation at various temperatures is outlined in Annex B of EN 253:2009.

This European Standard specifies requirements and test methods for valves of prefabricated thermally insulated valve assemblies comprising a steel valve, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with pre-insulated pipe assemblies in accordance with EN 253. This standard applies only to insulated valve assemblies for continuous operation with hot water at various temperatures in accordance with EN 253, Clause 1 and the valve assemblies with a maximum operation pressure of 25 bar. For higher pressures additional demands apply. Guidelines for quality inspection are given in Annex A of this standard. NOTE   For this application the following valve types are commonly used: ball valves, gate valves, and butterfly valves. This standard does not include calculation rules for loads and stresses. These depend on the configuration of the system as it is installed. The design and installation rules are given in EN 13941.

This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded single pipe assemblies for hot water networks in accordance with EN 13941-1, comprising a steel service pipe, polyurethane foam thermal insulation and a casing of polyethylene.
The pipe assembly can also include the following additional elements: measuring wires, spacers and diffusion barriers.

This European Standard provides requirements and test methods for flexible, pre-insulated, directly buried heating pipes with plastics service pipes and bonding between the layers of the pipes.
This European Standard is valid for maximum operating temperatures of 95 °C and maximum operating pressures up to 10 bar for a design lifetime of at least 30 years.
This European Standard does not cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this European Standard.

This European Standard provides requirements and test methods for flexible, pre-insulated, direct buried district heating pipes with plastic service pipes and no bonding between the layers of the pipes.
This European Standard is valid for maximum operating temperatures of 95 °C and maximum operating pressures up to 10 bar for a design lifetime of at least 30 years.
This European Standard does not cover surveillance systems.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this European Standard.

This European Standard provides classification, general requirements and test methods for flexible, pre-insulated, directly buried district heating pipe systems.
It is intended to be used in conjunction with parts 2, 3, 4, and 5.
Depending on the pipe assembly (see Table 4), this European Standard is valid for maximum operating temperatures of 95 °C to 140 °C and operating pressures of 6 bar to 25 bar.
The pipe systems are designed for a lifetime of 30 years. For pipe systems with plastic service pipes, the respective temperature profiles are defined in EN 15632-2 and EN 15632-3.
NOTE   For the transport of other liquids, for example potable water, additional requirements may be applicable.

This European Standard provides requirements and test methods for flexible, pre-insulated, directly buried district heating pipe assemblies with metallic service pipes and bonding between the layers of the pipes and thermal insulation materials of polyurethane or polyisocyanurate foam. Casing pipe shall be made from polyethylene.
This European Standard is valid for maximum operating temperatures up to 140 °C and pressures up to 25 bar for a design lifetime of at least 30 years.
NOTE   For higher temperatures or for the transport of other fluids, for example potable water, additional requirements and testing is needed. Such requirements are not specified in this European Standard.

This European Standard specifies requirements for design, calculation and installation of factory made thermal insulated bonded single and twin pipe systems for directly buried 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)   EN 13941-1: Design;
b)   EN 13941-2: Installation.
The requirements and stipulations in this part: prEN 13941-2, form an unbreakable unity with those of prEN 13941-1. This part shall therefore exclusively be used in combination with prEN 13941-1.
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.
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.

This European Standard specifies requirements and test methods for fittings of prefabricated thermally insulated pipe-in-pipe assemblies comprising a steel service fitting from DN 20 to DN 1200, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with preinsulated pipe assemblies in accordance with EN 253.
This European Standard covers the following fittings: bend, tee, reducer, single use compensator and anchor.
This European Standard applies only to factory made prefabricated fitting assemblies and single use compensators for continuous operation with hot water at various temperatures in accordance with EN 253.
This European Standard applies to fitting assemblies with a minimum design pressure of 16 bar (overpressure) complying with EN 13941.
This European Standard does not include calculation rules for loads and stresses. The design and installation rules, for the system, are given in EN 13941.

This European Standard specifies requirements and test methods for valves of prefabricated thermally insulated valve assemblies comprising a steel valve, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with pre-insulated pipe assemblies in accordance with EN 253.
This European Standard applies only to factory made prefabricated insulated valve assemblies for continuous operation with hot water at various temperatures in accordance with EN 253:2009+A1:2013, Clause 1 and the valve assemblies with a maximum operation pressure of 25 bar. For higher pressures, additional demands apply.
NOTE   For this application, the following valve types are commonly used: ball valves, gate valves, and butterfly valves.
This European Standard does not include calculation rules for loads and stresses. These depend on the configuration of the system as it is installed. The design and installation rules are given in EN 13941.

This European Standard specifies requirements and test methods for straight lengths of prefabricated thermally insulated pipe-in-pipe assemblies for directly buried hot water networks, comprising a steel service pipe from DN 15 to DN 1200, rigid polyurethane foam insulation and an outer casing of polyethylene. The pipe assembly may also include the following additional elements: measuring wires, spacers and diffusion barriers.
This standard applies only to insulated pipe assemblies, for continuous operation with hot water at various temperatures up to 120 °C and occasionally with a peak temperature up to 140 °C.
The estimation of expected thermal life with continuous operation at various temperatures is outlined in Annex B.

This European Standard specifies requirements and test methods for fittings of prefabricated thermally insulated twin pipe assemblies comprising steel service fittings and/or valves from DN 15 to DN 250, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with preinsulated twin pipe assemblies in accordance with EN 15698 1:2009.
This European Standard covers the following:
-   fitting assemblies, such as T-pieces, reducers and anchors;
-   valve assemblies.
This European Standard applies only to insulated fitting assemblies for continuous operation with hot water at various temperatures in accordance with the scope EN 15698 1:2009.
This European Standard applies to fitting and valve assemblies with a minimum design pressure of 16 bar (overpressure) complying with EN 13941.
Guidelines for quality inspection and testing of fitting assemblies are given in EN 448:2015, Annex A and EN 15698 1:2009, Annex A.
Guidelines for quality inspection and testing of valve assemblies are given in EN 488:2015, Annex A and EN 15698  1:2009, Annex A.
Procedures for PE-welding are given in EN 448:2015, Annex B.
NOTE   This European Standard does not include rules for calculation of loads and stresses.

This European Standard specifies requirements for joints made under field conditions between adjacent preinsulated pipes and/or fittings in district heating networks. The specified general requirements are also valid for field-made T branches, bends, reducers, caps, etc.
This European Standard covers jointing of steel service pipes by means of fusion welding, the connecting of casing ends with joint casings and the thermal insulation with poured rigid PUR foam or prefabricated PUR-foam insulation.
This European Standard specifies methods for type tests of complete joints and PUR-foam for joints under laboratory conditions.
The requirements of this European Standard can also be applied to casing pipe weldings/connections of on site made fittings.
The requirements of this European Standard aim to obtain a technical life of the joints of at least 30 years.

This European Standard specifies basic functional requirements for surveillance systems for district heating pipe systems, specific requirements for measuring elements and their installation within preinsulated bonded pipes, valves and fittings, and the field assembly of these measuring elements in pipe joints.
This standard specifies requirements for the manufacture of measuring elements, for the manufacture of preinsulated bonded pipe elements with measuring elements and for the assembly of the measuring elements in the field.
All requirements and recommendations described in this standard are based on the experience gained with existing surveillance systems and their principal function, cf. Annex A.
The specific requirements given are only valid for electrical wire based surveillance systems forming an integral part of the pipes, valves, fittings and joints.

This European Standard for District Heating Twin Pipes, specifies requirements and test methods for straight lengths of prefabricated thermally insulated pipe-in-pipe assemblies for directly buried hot water networks, comprising two steel service pipes from DN 15 to DN 250, rigid polyurethane foam insulation and one cylindrical outer casing of polyethylene. The pipe assembly may also include the following additional elements: Measuring wires, spacers and diffusion barriers.
This standard applies only to insulated twin pipe assemblies, for continuous operation with hot water at various temperatures up to 120 °C and occasionally with a peak temperature up to 140 °C.
The estimation of expected thermal life with continuous operation at various temperatures is outlined in Annex B of EN 253:2003.

This European Standard specifies rules for design, calculation and installation for preinsulated bonded pipe systems for buried hot water distribution and transmission networks (cf. Figure 2) with pipe assemblies in accordance with EN 253, for continuous operation with hot water at various temperatures up to 120ºC and occasionally with peak temperatures up to 140ºC and maximum internal pressure 25 bar (overpressure).
Application rule:
For larger pipe dimensions and pressures below 25 bar wall thickness bigger than specified in EN 253 can be required for straight pipes, bends and tees.
The principles of the standard can be applied to preinsulated pipe systems with pressures higher than 25 bar, provided that special attention is paid to the effects of pressure. Adjacent pipes belonging to the network (e.g. pipes in ducts, valve chambers, road crossings above ground etc.) can be designed and installed according to this standard.
The standard assumes use of treated water, which by softening, demineralisation, deaeration, adding of chemicals, or otherwise has been treated to prevent internal corrosion and deposits in the pipes.
This standard is not applicable for such units as:
a)   pumps,
b)   exchangers,
c)   boiler installations, tank installations,
d)   consumer installations.
However, the full functional ability and durability of such units should be ensured in consideration of the impacts from the district heating system and other impacts occurring from the conditions under which they have been installed.
Guidelines for product quality inspection and in situ tests of joints are given in Annex A of EN 448:2009, Annex D of EN 253:2009, Annex A of EN 488:2009 and Annex B of EN 489:2009.
Guidelines for welding of polyethylene casing are given in Annex B of EN 448:2009.
The estimation of expected life with continuous operation at various temperatures is outlined in Annex B of
EN 253:2009.

This European Standard specifies requirements and test methods for valves of prefabricated thermally insulated valve assemblies comprising a steel valve, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with pre-insulated pipe assemblies in accordance with EN 253.
This European Standard applies only to insulated valve assemblies for continuous operation with hot water at various temperatures in accordance with EN 253:2009, Clause 1 and the valve assemblies with a maximum operation pressure of 25 bar. For higher pressures, additional demands apply.
Guidelines for quality inspection are given in Annex A of this European Standard.
NOTE   For this application, the following valve types are commonly used: ball valves, gate valves, and butterfly valves.
This European Standard does not include calculation rules for loads and stresses. These depend on the configuration of the system as it is installed. The design and installation rules are given in EN 13941:2009+A1:2010.