Hydraulic valves are manufactured in a variety of styles to function in different applications. Valves are used to manipulate the flow of hydraulic fluid within a hydraulic circuit and are activated either mechanically or electronically. Directional Control Valves are the most commonly used valve in a hydraulic system. Control valves direct the flow of hydraulic fluid from the pump to the actuators or other sections of the hydraulic circuit. Control valves are returned to their neutral state with a spring or held in each position with a detent mechanism. These valves are generally used to control the direction of a hydraulic motor or cylinder; they can also perform other functions in a circuit.