scope:

This European Standard specifies requirements and test methodsfor fittings of prefabricated thermally insulated pipe-in-pipeassemblies comprising a steel service fitting from DN 20 to DN1200, rigid polyurethane foam insulation and an outer casing ofpolyethylene for use in directly buried hot water networks withpreinsulated pipe assemblies in accordance with EN 253. ThisEuropean Standard covers the following fittings: bend, tee,reducer, single use compensator and anchor. This European Standardapplies only to factory made prefabricated fitting assemblies andsingle use compensators for continuous operation with hot water atvarious temperatures in accordance with EN 253. This EuropeanStandard applies to fitting assemblies with a minimum designpressure of 16 bar (overpressure) complying with EN 13941. ThisEuropean Standard does not include calculation rules for loads andstresses. The design and installation rules, for the system, aregiven in EN 13941.