Actuator
Actuator turns up in 2 fields: valves, electrotechnology. Here is what it means to the people in each one.
Actuator in valves
The powered device that opens, closes or positions a valve using air, hydraulic oil or an electric motor.
Linear actuators push a stem, from spring-and-diaphragm units on control valves to large pistons on gate valves; rotary actuators turn a shaft through 90 degrees via scotch yoke, rack and pinion or vane mechanisms. Electric actuators use a motor and gearbox with torque and limit switches. An actuator is sized for the worst-case thrust or torque with margin, including breakaway torque after the valve has sat for months.
"Actuator's sized for clean gas, but that ball valve sat six months in the dirt, it needs another 30 percent breakaway torque."
Actuator in electrotechnology
The physical mechanism that drives the contacts of a switch or breaker.
The mechanical device that physically moves the heavy contacts inside switchgear or a circuit breaker. Actuators rely on stored energy from charged springs, compressed air, or magnetic coils to open or close the contacts with enough speed to extinguish electrical arcs.
"The breaker failed to close because the spring charging motor on the actuator burned out."