Rotary member 1 of the valve is forced into its seat in body 2 by helical springs 3 and has four passages and ports. In the position shown, the pump is connected through ports a and d to the working end of the power cylinder, and the tank through ports b and e to the low-pressure line. If member 1 is turned through 90°, the pump is connected through ports a and b to the high-pressure line and through ports d and e to the low-pressure line.
$3660$SHP,FC$