Which type of valve should be used to change the direction of motion of the cylinder in a hydraulic system?

A directional control valve is specifically designed to manage the flow of hydraulic fluid in a system, allowing for the control of the direction of motion in actuators, such as cylinders. When this valve is actuated, it changes the path that the hydraulic fluid takes, redirecting it to either extend or retract the cylinder accordingly. This function is essential for controlling the movements of hydraulic machinery effectively.

In contrast, a pressure relief valve is meant to prevent excessive pressure in the system by diverting fluid back to the reservoir, while a flow control valve regulates the speed of the actuator by controlling the flow rate of the fluid. A regulating valve typically maintains a preset pressure level in the system rather than directing fluid flow. Thus, these other types of valves do not fulfill the specific requirement to change the direction of motion like the directional control valve does.