| 摘要 |
<p>An irrigation system flushing valve comprising a housing, a coupling inlet of said housing for coupling to an end of an irrigation line, a flushing valve outlet of said housing, a valve seating formed in said housing communicating with said inlet and with said outlet, valve obturating means juxtaposed with respect to said seating and displaceable with respect thereto from a sealing position wherein said inlet is closed with respect to said outlet to an open position wherein said inlet communicates with said outlet; an extensible membrane mounted in said housing and defining with said obturating means a valve enclosure located within said housing and sealed with respect to said outlet by said obturating means and flow restricting means effecting flow communication between said inlet and said valve enclosure; the arrangement being such that the hydraulic pressures in said valve enclosure and said inlet respectively act on opposite surfaces of said obturating means and when the hydraulic pressure in said valve enclosure equals or exceeds that in said inlet said obturating means is biased into said sealing position.</p> |
