LST EN 488-2011+A1-2014 区域供暖管道. 直埋式热水供应网用预隔热连接管道系统. 聚氨酯隔热和聚乙烯外部护套钢制给水管的钢阀门配件
District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Steel valve assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene