| 摘要 |
<p>A differential-pressure valve is described including a valve passageway formed through a fixed wall and closable by a valve member displaceable by a differential-pressure sensor biassed to close the valve passageway and subjected to the differential pressure such that the higher pressure tends to open the valve passageway and the lower pressure tends to close the valve passageway. The valve further includes an annular sealing surface between the sensor and the fixed wall through which the valve passageway is formed, which sealing surface circumscribes the valve passageway such that when the sensor is in its closed position, the annular sealing surface seals off a portion of the high-pressure face of the sensor from the high-pressure thereby increasing the differential pressure required to actuate the sensor to open the valve passageway, and when the sensor is in its open position the annular sealing surface exposes said portion of the high-pressure face of the sensor to the high-pressure thereby decreasing the differential pressure required to actuate the sensor to close the valve passageway.</p> |
