| 摘要 |
PURPOSE:To prevent a seal member for a valve element from being deteriorated due to contact with corrosive gas in a vacuum gate valve device in which the seal member is made into close contact with a seat surface on a valve housing so as to close an opening, by feeding inert gas to the seal member through a gas passage formed in the valve housing. CONSTITUTION:A valve housing 1 provided being connected to a chamber in a semiconductor manufacturing device, is formed therein with an opening 2, and is coupled in its upper part with a valve plate drive device such as a hydraulic cylinder through the intermediary of a bonnet flange 4. When the valve plate drive device is operated, a trapezoidal valve plate 6 is elevated through the intermediary of a valve rod 5 so as to open and close the opening 2. A seal member 8 such as an O-ring is provided on an outer surface 6a of the valve plate 6 which faces a seat surface 7a of a valve seat 7 on the valve housing 1, and a gap 9 defined between the outer surface 6a of the valve plate 6 and the inner surface of the valve seat 7 and is communicated with a plurality of gas passages 10 through which inert gas is introduced so as to prevent corrosive gas from making contact with the seal member 8. |
