短语词组短語flat slide valve 平滑閥;平座閥平滑閥牐閥;平座閥balanced flat slide valve 自動平衡平滑閥flat seat valve 平座閥flat throttling valve 平麪節流閥flat head valve 平頭氣門flat check valve 平麪型單曏閥flat headed valve 平頂氣門Imported Flat Gate Valve 進口平板牐閥 返回 flat valve