| 摘要 |
<p>The valve device disclosed includes first, second and third user ports. A pressure accumulator connects with the first user port. With the accumulator fully charged, a pressure port connected to a pump communicates with the second user port. With the accumulator evacuated, the pressure port communicates with the first user port. In the event of a fluid demand at the third user port connected to a closed-center user component, the pressure port will be connected to the third user port via a control valve.</p> |
