District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene; German version EN 253:2009+A2:2015— 56 стр.
District heating pipes - Pre-insulated flexible pipe systems - Part 1: Classification, general requirements and test methods; German version EN 15632-1:2009+A1:2014— 33 стр.
