NF E29-480-1994
地下热水管网的预隔热管道系统.钢制供水管道、聚氨基甲酸乙酯热绝缘材料及高密度聚乙烯外壳的钢阀门组件(欧洲标准EN 488)
Preinsulated bonded pipe systems for underground hot water networks. Steelvalve assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene.