Page 33 - PNEUMATIC AND HYDRAULIC

2.3 Directional Control Valve

Directional control valves are essentially used for distribution of energy in a fluid

power system. They establish the path through which a fluid traverses a given circuit.

For example, they control the direction of motion of a hydraulic cylinder or motor.
These valves are used to control the start, stop and change in direction of flow of

pressurized fluid. Pressure may gradually build up due to decrease in fluid demand or
due to sudden surge as valves opens or closes. Pressure control valves protect the

system against such overpressure. Table 2.2 is the classification of valve by

port/position count and Table 2.3 common spool type valve and the usage.

Table 2.2: Classification by Port / Position Count

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