Methods of actuation

The methods of actuation of pneumatic directional control valves is dependent upon the requirements of the task. The types of actuation vary, e.g.
- manually actuated
- mechanically actuated
- pneumatically actuated
- electrical and
- combined actuation.
The symbols for the methods of actuation are detailed in DIN ISO 1219.

When applied to a directional control valve, consideration must be given to the method of initial actuation of the valve and also the method of return actuation. Normally these are two separate methods. They are both shown on the symbol either side of the position boxes. There may also be additional methods of actuation such as manual overrides, which are separately indicated.