ÖNORM EN 448

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 standard covers the following fittings: bends, T-pieces, reducers and anchors. This standard applies only to insulated fitting assemblies for continuous operation with hot water at various temperatures in accordance with clause 1 of EN 253:2003. Guidelines for quality inspection are given in annex A of this standard. Procedures for PE-welding are given in annex B of this standard. NOTE This standard does not include rules for calculation of loads and stresses.