Gas or steam valves that are actuated by hydraulic actuators for example, are installed in turbines to regulate and control process procedures. A steam turbine, unlike a gas turbine, can use the valves to control the entire thermal energy of the turbine; in a gas turbine, only the quantity of fuel supplied is regulated as it is reflected by the dimensions of these actuators. The hydraulic actuators are offered in different versions for turbine power ranges of 25 to 1,600 MW for steam turbines and 25 to 375 MW for gas turbines, depending on the customer's needs.