Actuators are used for the automation of industrial valves and can be found in all kinds of technical process plants: they are used in wastewater treatment plants, power plants and even refineries. This is where they play a major part in automating process control.
The valve parts through which force is applied to move or position flow-directing elements.
void: an empty area or space; "the huge desert voids"; "the emptiness of outer space"; "without their support he'll be ruling in a vacuum"
A space or container from which the air has been completely or partly removed
the absence of matter
A space entirely devoid of matter
A gap left by the loss, death, or departure of someone or something formerly playing a significant part in a situation or activity