When handle 1 is turned clockwise about fixed axis A, valve 5 is opened. At this, fluid, delivered by the pump to port 6, opens check valve 7 and is admitted to the working main through port 3. When handle 1 is turned counterclockwise, valve 2 is opened. At this, fluid from the working main is drained through ports 3 and 4 to the tank.
$3922$LHP,FC$