Since the electric butterfly valve is composed of a butterfly valve and an electric device, how to correctly select the electric device after the electric butterfly valve is determined is an important factor related to whether the actual needs can meet the engineering needs. In the selection of electric devices, not only the aforementioned working environment, electrical control and general technical performance should be considered, but also the comprehensive technical performance of the electric butterfly valve device should be fully considered.
1, the allowable value of the stem diameter
The lift rod valve should be selected from the electric device to 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 lever valves are not equipped with a stem cover.
2. Connection between valve and electric device
The connection type and size of the valve and the electric device should conform to the national standard: GB/T12222-1989 connection of the multi-turn valve drive device, GB/T12223-1989 part of the rotary valve drive device connection.
3. 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 butterfly 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 choose the output torque margin too large. If you can't open the valve in actual work, it is unreasonable.