阀门用烧结阀座的PTFE和RPTFE的美标标准号或国标标准号？ASTM D4894-07 Standard Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials. 问：阀门用烧结阀座的PTFE和RPTFE的美标标准号或国标标准号？答：ASTM D4894-07 Standard Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials.聚四氟乙烯