What is Electric Actuator

What is a Electric Actuator ?

Electric actuator is a commonly used electromechanical device in the field of automatic control. Its broad definition is: a driving device that can provide linear or rotational motion. It uses a certain driving energy and works under a certain control signal.. Actuators use liquid, gas, electricity or other energy and convert it into driving action through motors, cylinders or other devices.

The advantages:

1. Higher control accuracy: Since the electrical signal directly controls the movement of the electric actuator, its control accuracy is higher, and more precise flow and pressure control can be achieved, which is suitable for occasions that require high-precision control.

2. More environmentally friendly and energy-saving: Electric actuators do not require the use of gas sources and matching pneumatic components, avoiding environmental pollution problems such as gas leakage, and have better energy utilization efficiency, which can reduce energy consumption costs.

3. Wider application scope: The application of pneumatic actuators is limited in high temperature, high pressure, corrosive media and explosive environments, while electric actuators can be applied to more complex and harsh working conditions, such as chemical industry, Oil, natural gas, nuclear power and other fields.

4. Longer life and reliability: The mechanical part of the electric actuator has a simple structure and is easy to maintain. At the same time, the electrical components adopt advanced technology, with high stability and low failure rate, which can greatly improve the reliability and life cycle of the equipment.

Types:

There are two types of electric actuators, generally divided into Part-Turn Electric Valve Actuator and Multi-Turn Electric Valve Actuator. The former mainly controls valves that require partial rotation, such as: Ball valves, butterfly valves, etc., the latter require multiple rotations of valves, such as gate valves, etc.

How to choose a suitable actuator?

Driving energy

The most commonly used driving energy is power or fluid source. If power is selected as the driving energy, three-phase power supply is generally used for large-size valves, and single-phase power supply can be used for small-size valves. Generally, electric actuators have a variety of power supply types to choose from.

Valve type

 

When selecting an actuator for a valve, it is important to know the type of valve so that the correct actuator type can be selected.

Torque size

For valves with 90-degree rotation, such as ball valves, butterfly valves, and plug valves, it is best to obtain the corresponding valve torque from the valve manufacturer. Most valve manufacturers test the operating torque required by the valve under rated pressure. They will torque is provided to the customer.

 

The situation is different for multi-turn valves. These valves can be divided into: reciprocating (lifting) movement - the valve stem does not rotate, reciprocating movement - the valve stem rotates, non-reciprocating - the valve stem rotates. The valve stem must be measured. Diameter, the size of the valve stem connection thread determines the actuator specifications.

Actuator selection

Once the actuator type and the required driving torque of the valve are determined, the selection can be made using the data sheet or selection software provided by the actuator manufacturer. Sometimes the speed and frequency of valve operation also need to be considered.

Fluid-driven actuators have adjustable stroke speed, but electric actuators with three-phase power only have fixed stroke times.

 

Some small-sized DC electric single-turn actuators can adjust the stroke speed.