A useful application of servo valves is power generating plants, such as a dam or a nuclear power plant. These facilities have thousands of pipes carrying water and steam. If humans constantly had to turn valves on and off, hundreds of people would be needed. By placing servos and sending units on top of valves, an operator can see all the valves on a computer screen. He can tell if a valve is on or off. From his seat, he issues commands to the servos to turn valves on or off.
A servo valve is used for hydraulic motor control, according to the Georgia Institute of Technology. A hydraulic motor uses flowing hydraulic fluid to generate a spinning motion on the shaft. A servo valve controls the flow of the fluid, so that the motor can spin in either direction. The operator simply pushes a button, and the valve directs the flow of the fluid, thus controlling the direction of spin.
An automated assembly line often has thousands of hydraulic mechanisms, all controlled by servo valves. For example, a part is lifted up by a hydraulic piston. A valve is needed to control the extension or retraction of the piston. Without computerized control, the precise movements needed would be impossible. The computer controls the servo, and the servo turns the valves on and off to control the movement of the pistons.