DIN EN 253:2009

District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene; German and English version EN 253:2009 (Foreign Standard)

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 20 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 varioustemperatures up to 120 C and occasionally with a peak temperature up to 140 C. The estimation of expected thermal life withcontinuous operation at various temperatures is outlined in annex B.