Hydraulic control device for an emergency stop valve of a steam turbine and steam turbine arrangement

A hydraulic control device for an emergency stop valve of a steam turbine, comprising:

• a module for reducing a hydraulic pressure by rapid opening of an outflow valve and/or changing a load on an actuator for actuating the emergency stop valve;
• a control valve arrangement with at least three safety valves provided in an operating medium supply and/or conducting system, said at least three safety valves being hydraulically interconnected to open the outflow valve or change a load on the actuator only when a safety circuit by way of at least two safety valves of said control valve arrangement have assumed an emergency stop position;
• at least three precontrol valves, with a respective said precontrol valve hydraulically connected upstream, in a flow direction from a pressure source towards a pressure sink, of each said safety valve and independent from remaining said safety valves, wherein the respective said safety valve that is connected downstream of a respective said precontrol valve can be hydraulically decoupled from the respective said precontrol valve during operation, and wherein said three precontrol valves are connected in parallel.