How to select the electric actuator for an electric butterfly valve?

1. The allowable value of the valve stem diameter

For the selection of an electric actuator for a lift stem valve, attention should be paid to the allowable diameter of the valve stem that can pass through it.For the selection of an electric actuator for a lift stem valve, attention should be paid to the allowable valve stem diameter value that the actuator can pass through. The valve stem diameter must be less than this value. The valve stem diameter must be less than this value. Additionally, for multi-turn electric actuators, requirements for the height of the valve stem cover should also be specified when choosing. Additionally, for multi-turn electric actuators, requirements for the height of the valve stem cover should also be specified when choosing. For rotary stem valves, a valve stem cover is not necessary.

2.The connection between the valve and the electric actuator

The connection type and size of the valve and the electric actuator should comply with standards.

3. The output torque and speed of the electric actuator

The output torque value is one of the important technical parameters of the electric actuator and is also an important parameter to be selected during use.The output torque value is one of the important technical parameters of the electric actuator and is also an important parameter to be selected during use. If the output torque of the selected electric actuator for assembling the electric valve is too large or too small, it is not advisable. If the output torque of the selected electric actuator for assembling the electric valve is too large or too small, it is not advisable. Because generally, the output torque value of the electric actuator needs to be tested and adjusted before leaving the factory, which is relatively accurate. Because generally, the output torque value of the electric actuator needs to be tested and adjusted before leaving the factory, which is relatively accurate. If an excessive output torque margin is selected, it will make the electric valve have a great potential danger. If an excessive output torque margin is selected, it will make the electric valve have a great potential danger. In case of control and protection failure, it will easily cause valve damage (valve stem bending, valve body cracking), and easily cause pipeline system accidents. In case of control and protection failure, it will easily cause valve damage (valve stem bending, valve body cracking), and easily cause pipeline system accidents. Therefore, choosing an excessively large output torque margin is not advisable. Therefore, choosing an excessive output torque margin is not advisable. If the valve cannot be opened in actual work, it also belongs to an unreasonable selection.

Because unnecessary high speed, under the same torque requirement, will increase the motor power.Because unnecessary high speed, under the same torque requirement, will increase the motor power. This not only wastes energy, increases the engineering cost, but also makes the electric actuator larger in size, causing various wastages.

4. The allowable maximum thrust of the electric actuator

If the axial force of the valve is borne by the electric actuator (that is, the valve stem nut is in the electric actuator), the thrust value must not exceed the allowable value of the electric actuator.

5. The maximum number of turns of the valve stem nut

When selecting a multi-turn electric actuator for a valve, the maximum number of turns of the valve stem nut during the valve's operation must be specified.When selecting a multi-turn electric actuator for a valve, the maximum number of turns of the valve stem nut during the valve's operation must be specified. This can correctly select the relevant gear ratio of the position indication mechanism in the electric actuator to ensure sufficient accuracy of the position indication for observing the opening and closing degree of the valve during its operation. Otherwise, it is likely to cause illusion and affect normal operation.

At present, some rotary valve electric actuators have mechanical limiters to prevent the inability to determine the valve disc position.At present, some rotary valve electric actuators have mechanical limiters to prevent the inability to determine the valve disc position. The corresponding relationship between the connection holes and key slots between such valves and electric actuators requires strict requirements. The corresponding relationship between the connection holes and key slots between such valves and electric actuators requires strict requirements.