DS EN 488:2011 District Heating Pipes - Preinsulated Bonded Pipe Systems For Directly Buried Hot Water Networks - Steel Valve Assembly For Steel Service Pipes, Polyurethane Thermal Insulation And Outer Casing Of Polyethylene Provides 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