Directional control valves are used in hydraulic systems to change the direction or open and close the flow path, and in general a directional control valve controls the direction of the oil in the communication paths of the hydraulic system.

Directional control valves are used in all hydraulic systems and are installed on the hydraulic block to determine the direction of fluid movement. In control valves, it moves in the direction of a spool inside a cylinder and opens or closes the path of the oil.

The importance and difference of good or bad hydraulic valves in flow control is in the accuracy of construction and observance of geometric and dimensional tolerances. If the steering control valve does not work well in a hydraulic system, the whole system will fail, such as one jack after moving a certain course and another jack will do the rest if the steering control valve for that jack is broken and stuck or leaking The jack will have less or more courses, which will damage the system.