| 摘要 |
<p>A valve, for diverting a flow of water to be passed in one direction or the reverse through a water rejuvenation bed (such as a filter for trapping detritus or organisms, or an ion exchange bed) comprises a ported tubular body within which a free spool carrying a plurality of partitioning seals may slide between a first position and a second position by hydraulic pressure applied to the seal at one end or the other of the spool. The hydraulic pressure from a pilot line, is applied momentarily through a solenoid valve actuator sealed over at each end of the tubular body in a "push-push" symmetrical configuration and driven by a controller according to a timer; optionally also supplied with bed performance signals (such as trans-filter pressure). The solenoids themselves require little driving power and the valve is simple in construction.</p> |
