短语词组短語diaphragm valve spring seat [鉄路]膜片閥彈簧座valve -seat cutter 氣門座銑刀valve spring seat pin 氣門彈簧座銷ventilator valve spring seat 通風閥簧座butterfly valve valve seat 蝶閥閥座Safety valve spring seat 安全閥彈簧座 返回 valve seat