FLUID CONTROL VALVE

摘要

The invention relates to a gate valve (10) having both visual and electrical position indicating means for signalling when the valve is in the fully open and fully closed conditions. A position indicator housing (50) on the valve body (11) receives and accommodates therein a longitudinal valve stem extension (33) of the gate element (15) as the gate element moves between the open and closed positions. The indicator housing (50) is filled with transparent oil and sealed off from fluid communication with the valve chamber (12) and a diaphragm (135) in the wall of the indicator housing accommodates movement of the gate extension (33) inwardly and outwardly of the indicator housing (50) and is exposed to the fluid environments internal and external of said housing to avoid pressure differentials across the housing wall. A pair of proximity sensors (100, 104) with sensing elements (101, 106) of the electrical impedance type are mounted in the indicator housing (50) adjacent the valve stem extension (33) of the gate element at locations corresponding to the extremities of travel of the gate (15) and extension (33) thereof. The sensors energize associated electrical circuit means (FIG. 6) to signal to a remote monitoring facility (M) when the valve (10) is in the fully open or fully closed position. In addition, a pair of viewports (W) are provided in opposed locations of the indicator housing (50), particularly for subsea applications, to permit visual assessment of valve element position.