The model B TA-711, one way Altitude valve controls the high water level in elevated Tanks or reservoirs. The altitude pilot senses the hydrostatic head of the reservoir to close on high water level. When the water level drops below the predetermined set point the valve opens to fill the reservoir. Supply pressure is greater than static head pressure. Tank discharge is by separate line.
This is a hydraulically operated and pilot controlled valve which operates on the differential in forces between a spring load and the water level in the reservoir. The desired high water level is set by adjusting the spring force. The pilot control measures the head through a sensing line directly connected to the reservoir.