Hydraulic (pressurised) actuation of a valve by a small, directly solenoid actuated valve (pilot valve). Here the pilot valve is mostly directly on the main valve (Figure E 19). With this combination it is also possible to control large valves with low electrical power (gain factor up to 105), which can be undertaken as quickly or, by installing a throttle valve in between, as slowly as required. On the usage of proportional solenoids the main valve can follow any ramp.
Figure E 19: Electro-hydraulically actuated directional valve