To introduce one kind of ball valve sealing structures which is formed through bringing pressure on the seat ring while the ball or disc is rolling towards the seat ring parallelly.是什么意思_To introduce one kind of ball valve sealing structures which is formed through bringing pressure on the seat ring while the ball or disc is rolling towards the seat ring parallelly.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句