These directional valves control the oil flow in combination with hydraulic power packs (YHH-4/3 with
hand pumps).
All valves have 3 lever positions to control movement
of the connected hydraulic cylinder:
1. left: cylinder advance.
2. middle: cylinder neutral (pressureless circuit).
3. right: cylinder retracts.
In the middle position (hold) the piston of the cylinder stops and the oil flow is guided in a circuit back to the reservoir (P to T). The valves can be flanged directly onto power packs or remote connected by using hydraulic piping.

In addition all valves are equipped with a second
pressure oil port P at the back of the valve base. This
port can easily be used to connect a pressure gauge
and a pressure relief valve (e.g. VPR-1). The oil port T
shall always be connected to the reservoir without any
back pressure.