| 摘要 |
<p>A ball valve disclosed herein is low cost and offers a fast and reliable valve operation. Furthermore, the actuating force the ball valve requires, when it is shut off, is small. The ball valve is capable of fine adjustment of the flow. The ball valve comprises a valve casing (20) defining a flow path (20) of a fluid, a valve seat (6) disposed in the midway of the flow path, a valve element (5) which is in engagement with the valve seat or out of engagement with the valve seat, to shut off the flow path or to regulate the flow rate in the flow path, a control rod (7) inserted into the valve casing and movable upward and downward, and a connecting rod (9), one end of which is rotatably supported at the inner end of the control rod, and the other end of which is connected to the valve element. The valve element comprises a communication path which communicates with both the upstream side of the flow path and the downstream side of the flow path and an on-off means for opening or closing the communication path. <IMAGE></p> |
