4/3-way proportional valve

By use of a twin-channel proportional amplifier, the proportional valve transforms an analog electrical input signal into corresponding opening cross-sections at the outputs. The setpoint signal must be within the range -10 V to +10 V. At 0 V the hydraulic mid-position is adopted and the valve stops the flow (in relation to the null overlap).

The cross section area of the flow opening widens by increasing slide distance. How far the area, and with it the flow at the valve, changes depends on the shape and form of the control notches. A triangular shaped notch results in a progressive flow behavior, a rectangular shaped notch in a linear flow behavior.

The hydraulic resistance relates to a completely opened leading edge and the internal leakage relates to one leading edge as appropriate. The overlaps of the leading edges can be specified relative to the maximal slide distance. Two different overlaps can be specified for the leading edges of P and T.