Electro-Hydraulic Valves
                An Electro-Hydraulic Servo Valve or EHSV is an electrically operated 
                
valve that controls how hydraulic fluid is ported to an actuator. 
                
Servo valves and Servo-Proportional Valves operate by transforming 
                
a changing analogue or digital input signal into a smooth set of movement 
                
in a hydraulic cylinder. Servo valves can provide precise control of 
                
position, velocity, pressure and force with good post movement damping characteristics.