| 摘要 |
PURPOSE:To reduce erosion and lower an opening and closing force, by providing a plate-shaped valve element in a valve casing near its one end so that the valve element perpendicularly intersects a fluid passage and can reciprocate and by providing a cylindrical valve seat which can be brought into contact with the plate-shaped valve element and can slide back and forth along the passage. CONSTITUTION:A valve casing 1 is provided with a fluid passage 6 including an inlet port 2 and an outlet port 3. A plate-shaped valve element 4 is provided in the valve casing 1 so that the element can reciprocate perpendicularly to the passage 6. A cylindrical valve seat 5 provided with a through passage 5a is slidably fitted in the passage 6. A flange 20 is formed on the peripheral part of the valve seat 5 so that a piston-cylinder relationship is established between the valve seat and the valve casing 1. To reciprocating the plate-shaped valve element 4, driving liquid is first supplied through a feed/drain port 25 to move the valve seat 5 back out of contact with the valve element and thereafter drive the element forward and backward. After the valve element 4 is moved, driving liquid is supplied again through a feed/drain port 24 to move the valve seat 5 forth into contact with the valve element to perform sealing. |
