美利体育登录入口官网:BS EN 489:2009 区域供热管道.直埋热水网络预装管道系统.供热钢管道,聚氨酯保温层及聚乙烯外层的联合装配
District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Joint assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene