Abstract: An electrohydraulic compact drive for turbomachine valves includes: a device for supplying electric power, receiving electrical addressing signals and converting the signals into positioning and control variables; an hydraulic supply system including a fluid tank, pump, motor, accumulator and manifold; an hydraulic power piston/cylinder system including a piston rod connected to a valve, and a spring biasing the piston; an electrohydraulic addressing system generating a pressurized fluid flow opening the valve spindle against the spring dependent upon the variables; control members of the addressing system, the power system and the supply system forming a compact drive block at a valve; the pump being switched as a function of a pressure limit by intermittent charging and discharging operations between the charging pressures; the pump charging the accumulator in charging operation until the upper pressure is reached and, after being switched, returning the fluid to the tank in substantially pressureless circu

Abstract: An electrohydraulic actuating drive for a valve is constructed as a compact drive block which is mounted on the housing of the valve. The drive block includes a support structure which supports other components of the actuating drive on the valve housing and which includes a storage receptacle for a low-pressure hydraulic fluid.

Abstract: Monitoring device for steam-turbine valves having respective electrohydraulic servocontrol devices for directly controlling the valves individually, including means for monitoring operability of the respective servocontrol devices, the operability monitoring means including means for comparing a value of a variable of each one of the servocontrol devices determining a setting of the respective valve with a mean value of corresponding variables of others of the servocontrol devices determining respective settings of valves associated with the other servocontrol devices and for establishing from the comparison if a permissible deviation from the mean value is exceeded by the variable value of the respective one of the servocontrol devices, and means for controlling a valve drive associated with the respective valve controlled by the respective one of the servocontrol devices for driving it in closing direction thereof when the permissible deviation from the mean value is exceeded.