Student Engineer  


Directional Control Valves

Directional control valves are an integral part of pneumatic systems, they can change the direction of flow to it's outputs in a split second.

Directional control valves can be operated in number of different ways, the most common in industry today is via solenoid, this allows valves to be operated electronically by computer programs (PLC) enabling accurate timing of valve control down to milliseconds.

Below is a diagram of a 5 port / 3 position directional control valve. 5 ports because there are a combined total of 5 inputs/outputs and 3 functioning positions of the valve, one will direct flow to (A) and one to (B) the shuttle, which is the stem through the middle of the valve will when centralised close all ports on the right hand side of the valve, effectively blocking any flow of air through the valve. (see fig. 2)

Operation of directional control valve
Figure 1


A directional control valve in a centralised position
Figure 2

<<< Back © 2010