Pneumatic stirrers are preferred for the above applications because :
They do not get damaged even though there is any excess load. They simply get stalled temporarily and start normal working when the excess load is removed
Their speed can be varied step-lessly by using simple pneumatic valves. No complicated circuits or control panels are required.
There is no fear of electrical shocks. Therefore, they can be used even in wet surroundings.
They are light in weight and compact in size. This saves space.
Because of light weight, some models can be used as portable hand held stirrers which can be moved anywhere in the factory and can be used for different applications
They can be used with gearboxes to give higher torques at lower speeds
Bearing support can be provided to the stirrer rod to prevent oblong running of the stirrer