NF E39-017-1:2009 District heating pipes - Preinsulated bonded twin pipe systems for directly buried hot water networks - Part 1 : twin pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene.
2009NF E39-017-1:2009 District heating pipes - Preinsulated bonded twin pipe systems for directly buried hot water networks - Part 1 : twin pipe assembly of steel service pipe, polyurethane thermal insulation and outer casing of polyethylene.