Five parameters of the butterfly valve electric head must be introduced

Since the electric butterfly valve is composed of a butterfly valve and an electric actuator, how to correctly select the electric actuator after the butterfly valve is determined is an important factor related to whether the actual needs can meet the engineering needs. In the selection of butterfly valve electric actuators, not only the aforementioned working environment, electrical control and general technical performance should be considered, but also the comprehensive technical performance of the electric device should be considered.

1. Connection of valve and electric device

The connection type and size of the valve and electric device should conform to the national standard: GB/T12222-1989 connection of multi-turn valve drive device, GB/T12223-1989 part of rotary valve drive unit

2. Allowable value of stem diameter

The lift rod valve selection electric device should pay attention to the stem diameter value that it is allowed to pass, and the stem diameter must be less than this value. In addition, for multi-turn electric devices, the height of the stem cover should be raised when selecting (related to the valve pain path). Rotary rod valves are not equipped with a stem cover.

3. The maximum thrust allowable value of the electric device

If the axial force of the valve is borne by the electric device (ie the stem nut is in the electric device), the thrust value must not exceed the permissible value of the electric device.

4. Output torque and speed of electric device


The output torque value is one of the important technical parameters of the electric device, and it is also an important parameter that needs to be selected during use. If the output torque of the electric device selected when the electric valve is assembled is too large or insufficient, it is not preferable. Because of the general situation, the electric device manufacturer needs to test and adjust the output torque value when the product leaves the factory, which is relatively accurate. If the excessive output torque margin is selected, the electric valve will have great potential danger. Once the control protection failure occurs, the valve will be easily damaged (the valve stem is bent and the valve body is broken), which is easy to cause. Pipeline system accident. Therefore, it is not advisable to select the output torque margin too large. If you can't open the valve in actual work, it is unreasonable.

Regarding the determination of the output speed of the electric device, when the valve is not strictly required for its opening and closing time, the slower speed should be selected as much as possible.

Because of the unnecessarily fast speed, the motor power will be increased under the same torque requirement, which not only wastes energy, increases engineering cost, but also causes the electric device to increase in volume and cause various wastes.

At present, the electric devices developed and developed in China have a small number of motor specifications designed in each frame number (generally 2-3 specifications), and the speed ratio range of the gear pair and the worm gear pair in the main transmission is limited. Therefore, there is not much torque binning and speed binning for each frame number.

5. The number of large turns of the stem nut