| 摘要 |
<p>A valve has a valve member 17 moveable along an axis in a valve chamber between open and closed positions. In the open position the valve member 17 is displaced from its valve seat 21 such that a fluid inlet 3 is connected to a fluid outlet 2. In the closed position the valve member is sealed against the valve seat 21 to close the fluid path. First 12 and second 46 opposed stacks of disc springs apply unequal loading resulting in a biasing force that biases the valve member 17 towards its closed position. A first piston member 15 is movable in a bore 14 relative to the valve member for moving the valve member in a first direction along the axis. A second piston member 16 is movable in the bore 14 relative to the valve member for moving the valve member along the axis in a second direction opposite to the first direction. A first pressure compensation passage 71 extends between the fluid inlet 3 and the bore 14 such that the first piston member 15 is acted on by the fluid pressure in the fluid inlet 3. A second pressure compensation passage 70 extends between the fluid outlet 2 and the bore 14 such that the second piston member 16 is acted on by the fluid pressure in the fluid outlet 2. An actuator (50, Fig. 2) may manually move the valve member 17 from the closed position to the open position.</p> |
