DIN EN 448 District heating pipes - Bonded single pipe systems for directly buried hot water networks - Factory made fitting assemblies of steel service pipes, polyurethane thermal insulation and a casing of polyethylene; German and English version prEN 448:2023 ...*, 2023-08-01 Update
DVS 2207-5-1993 history
1993DVS 2207-5-1993 Welding of thermoplastics - Welding of PE casing pipes - Tubes and tubular components