Historical
BS 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 (British 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 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.
British Standards Institution [bsi]