What is the proper name for the operator of steam valves?

The proper name for the operator of steam valves is an actuator. Actuators are devices that convert a control signal into mechanical motion, which in the case of steam valves means they operate the valve itself to control the flow of steam. Actuators can be powered by various means, such as electrical, pneumatic, or hydraulic systems. They play a crucial role in automation, allowing for precise control of temperature, pressure, and flow in steam systems.

The other options correspond to different functionalities in a control system. The controller typically refers to a device or software that processes input signals and sends commands to the actuator based on pre-set parameters. A regulator is responsible for maintaining a certain set point, such as pressure, often using feedback but does not directly operate the valve. Lastly, a sensor detects specific parameters like temperature or pressure but does not perform any action or control the valve directly. Hence, actuator is the accurate term for the operator of steam valves.