GB/T 34611-2017硬质聚氨酯喷涂聚乙烯缠绕预制直埋保温管国家标准
英文:Rigid polyurethane spray polyethylene winding prefabricated directly buried insulating pipes GB/T 34611-2017介绍: 国家标准《...
英文:Rigid polyurethane spray polyethylene winding prefabricated directly buried insulating pipes GB/T 34611-2017介绍: 国家标准《...