GB/T 38105-2019城镇供热钢外护管真空复合保温预制直埋管及管件国家标准
英文:Urban heating—Steel jacket prefabricated directly buried pipes and fittings with vacuum insulating layers GB/T 38105-...
英文:Urban heating—Steel jacket prefabricated directly buried pipes and fittings with vacuum insulating layers GB/T 38105-...