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 .
This standard is not applicable for such units as:
b) heat exchangers;
c) boilers, tanks;
d) systems behind domestic substations.