Electric actuators are crucial devices in industrial automation control systems. Their core function can be summarized as: receiving command signals from the control system and converting them into corresponding linear or rotary mechanical motion to drive final control elements such as valves, dampers, and baffles, thereby achieving precise regulation or on/off control of process parameters such as flow rate, pressure, temperature, and liquid level.
Key Points for Electric Actuator Selection
When selecting an electric actuator, the following key parameters must be considered:
1. Output Type: Angular stroke, multi-turn, or linear stroke?
2. Torque/Thrust Value: This is the most critical parameter. It must be greater than the maximum torque/thrust required for valve operation, with a safety margin (usually 1.5 times).
3. Operating Speed: The time required for the valve to go from fully closed to fully open.
4. Control Signal: Are the input and feedback signals 4-20mA, or is it bus communication?
5. Power Supply Voltage: AC220V, AC380V, or DC24V?
6. Protection Rating: IP67 or IP68, etc., selected according to the installation environment.
7. Explosion-proof Rating: If used in flammable and explosive environments, such as the petroleum and chemical industries, an explosion-proof type (e.g., ExdIIB T4Gb) must be selected.
8. Interface with Valves: Complies with international standards such as ISO and DIN, or matches the valve manufacturer's specifications.
Main Application Areas of Electric Actuators
Electric actuators are widely used in almost all industrial fields requiring automated control:
* Petrochemical Industry: Reactor, pipeline valves, storage tank control.
* Power Industry: Boiler feedwater, steam regulation, flue gas desulfurization systems.
* Water Treatment: Water pump control, chemical dosing valves, large pipeline valves.
* Metallurgical Industry: Blast furnace, heating furnace gas and air regulation.
* Pharmaceutical and Food Industry: Sanitary process control.
Building automation: Control of air dampers and water valves in central air conditioning systems.
