District heating pipes - Bonded twin pipe systems for directly buried hot water networks - Part 1: Factory made twin pipe assembly of steel service pipe@ polyurethane thermal insulation and a casing of polyethylene
This document specifies requirements and test methods for straight lengths of factory made thermally insulated bonded twin pipe assemblies for directly buried hot water networks in accordance with prEN 13941-1@ comprising two steel service pipes@ 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.