Directional control valves are one of the most fundamental parts in hydraulic machinery. They allow fluid flow into different paths from one or more sources. They usually consist of a piston inside a cylinder which is mechanically or electrically controlled. The movement of the cylinder restricts or permits the flow, thus it controls the fluid flow.

Directional Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening or closing in response to signals received from controllers that compare a “setpoint” to a “process variable” whose value is provided by sensors that monitor changes in such conditions.

Directional and 4 way control valves: Directional control valves usually means to control the direction of the the actuator. If you have a hyd. motor, the valve would control which rotation it would use, such as forward and reverse or clockwise and counter clockwise. If you are controlling a cylinder, the valve would control it to extend and retract. Directional control valve also could mean to control which way the pump flow goes. A selector valve, for example, controls the flow from the pump to one line or another, giving the system an extra circuit to be used from the same pump. 4-way control valves are essentially the directional control valve. Controlling pump flow direction from the control valve to the actuator and allowing return flow to go through the control valve and back to the tank. In one spool position of the valve, the flow from the pump is ported from the inlet port to the A work port (which then goes to the actuator) and (coming from the actuator) to the B work port the flow is ported to the outlet port. Flow passes throught the valve twice. In the opposite spool position, the flow is ported from the inlet to the B work port (which then goes to the actuator) and (coming from the actuator) to the A work port the flow is ported to the outlet port. Flow passes thought the valve twice. With the 2 postions of the spool, the flow passes throught the valve 4 times – 4 way valve.

	V20 Directional Control Valve
	DVA20/DVG20 Directional Control Valve
	DVA35/DVG35 Directional Control valve
	DVG80 Directional Control Valve
	V90 Directional Control Valve