The most common applications in valves are, for stem material in butterfly valves, and backseat bushings and wedges in cast steel valves.是什么意思_The most common applications in valves are, for stem material in butterfly valves, and backseat bushings and wedges in cast steel valves.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句