District heating pipes - Bonded twin pipe systems for directly buried hot water networks - Part 2: Factory made fitting and valve assemblies of steel service pipes@ polyurethane thermal insulation and one casing of polyethylene
This document specifies requirements and test methods for fittings of factory made thermally insulated bonded twin pipe assemblies for hot water networks in accordance with prEN 13941-1@ comprising two steel service fittings and/or valves@ rigid polyurethane foam insulation and one casing of polyethylene. The pipe assembly can also include the following additional elements: Measuring wires@ spacers and diffusion barriers. This document covers the following assemblies: ?? fittings: bends@ T-pieces@ reducers and anchors; ?? valves constructions. This document applies to fitting and valve assemblies with a minimum design pressure of 16 bar (overpressure).