| 摘要 |
<p>A relief and make-up valve assembly is connected to first and second fluid pressure passages in a fluid pressure device. The valve assembly includes a housing of a hollow cylindrical form which communicates with the passages, a valve axially movable in the housing, a piston partitioning the interior of the housing into a low pressure chamber and a back pressure chamber, and a plunger biased by the piston against the valve to move the valve to an opened position away from a valve seat. The valve assembly controls the level of pressure in the first pressure passage by unseating the valve to relieve a preselected pressure from the first pressure passage or alternately to build up a pressure therein.</p> |
