This European Standard specifies requirements and test methods for valves of prefabricated thermally insulated valve assemblies comprising a steel valve, rigid polyurethane foam insulation and an outer casing of polyethylene for use in directly buried hot water networks with pre-insulated pipe assemblies in accordance with EN 253. This European Standard applies only to insulated valve assemblies for continuous operation with hot water at various temperatures in accordance with EN 253:2009, Clause 1 and the valve assemblies with a maximum operation pressure of 25 bar. For higher pressures, additional demands apply. Guidelines for quality inspection are given in Annex A of this European Standard. NOTE For this application, the following valve types are commonly used: ball valves, gate valves, and butterfly valves.This European Standard does not include calculation rules for loads and stresses. These depend on the configuration of the system as it is installed. The design and installation rules are given in EN 13941:2009+A1:2010.