Hydraulic Directional Control Valves

Directional control valves are one of the most important parts of hydraulic and pneumatic machines. They allow fluid flow to the different paths from one or more sources.
Directional valves usually consist of a moving spool inside a cylinder. The liquid flow is controlled by the position of the spool which restricts or permits the flow. The spool can be controlled manual, hydraulic, pneumatic or electrical/solenoid.