Actuator

An actuator is an important component in industrial automation and process control. Its task is to operate the actuating element of a valve or other control component (e.g., throttle body, slide valve) in order to precisely control physical variables such as pressure, temperature, or flow. The actuator receives a control signal from the controller and converts it into a mechanical movement that opens, closes, or gradually regulates the actuator accordingly.

Design and function

An actuator typically consists of an actuator (e.g., electrically, pneumatically, or hydraulically operated) that converts the signal from the controller into motion. The most common types of actuators in industry are:

• Pneumatic actuators: Use compressed air to control the movement of the actuator. They are fast and robust, making them suitable for many industrial applications.
• Electric actuators: Use electric motors to change the valve position. They offer high precision and are often used in applications with moderate speeds.
• Hydraulic actuators: These actuators work with hydraulic fluids and offer high power transmission for applications with high pressures and large actuating forces.

The actuator receives a control signal (e.g., 4-20 mA for electric systems or 0.2-1.0 bar for pneumatic systems) and positions the actuator (e.g., control valve) accordingly to achieve the desired process state.

Areas of application

Actuators are used in a wide range of industries and processes, including:

• Chemical and petrochemical industry: For controlling reaction processes and flow rates.
• Power generation: For controlling steam valves and boiler controls.
• Pharmaceutical and food industry: For precise control of sterile processes.

Advantages of the actuator

• High precision: Actuators enable exact control of the actuator, which ensures precise control of process variables.
• Fast response time: Pneumatic actuators in particular offer fast control responses, which is advantageous in dynamic processes.
• Robustness: Actuators are designed for use in demanding environments where high temperatures, pressures, or aggressive media prevail.

Summary

The actuator is a central element of process control that converts the control signal from the controller into mechanical movement in order to control the process safely and efficiently. Its adaptability to different drive types and its high precision make it indispensable in industrial automation.