此閥為各系統儀表安裝的專用產品，閥門打開，進氣口與出氣口接通，排氣口關閉。當手輪旋轉90°，進氣口與出氣口切斷，出氣口與排氣口接通，排出測量儀表氣體。 It is a special product of various gauge installions. While the vavle opening,the admissior is connected with the oatlet and exhaust is closed when the handle is turned 90°,the admission abd outlet are cut off but the outlet is connected with the exhaust and the gauge gas is exhauster.
