As the electric butterfly valve is compose of butterfly valve and electric device. How to select the electric device correctly after the butterfly valve is determine is an important factor related to whether it can meet the needs of the project in actual use. When selecting the electric device, not only the working environment, electrical control and general technical performance mentioned above shall consider. But also the comprehensive technical performance of the electric device shall comprehensively consider.

1. Allowable valve stem diameter:

When selecting the electric device for the lifter valve, pay attention to the allowable valve stem diameter, which must be less than the value. In addition, for multi turn electric device, the height of the valve stem cover should also require (related to the valve diameter). Rotary stem valve can not be equipped with stem cover.

2. Connection between valve and electric device:

The connection type and size of the valve and the electric device shall conform to the national standard: the connection of the multi turn valve driving device and the connection of the part of the turn valve driving device in GB / t12223-1989.

3. Output torque and speed of electric device:

The output torque value is one of the important technical parameters of the electric device. And also an important parameter to be selected in use. If the output torque of the electric device used in assembling the electric valve is too large or insufficient, it is not advisable. Generally speaking, the electric device manufacturer needs to test and adjust the output torque value when the product leaves the factory. Which is relatively accurate.

4. Allowable maximum thrust of electric device:

If the axial force of the valve is borne by the electric device. The thrust value shall not exceed the allowable value of the electric device.

5. Maximum turns of stem nut:

When selecting the electric device of multi turn valve, it is necessary to state the maximum number of turns of the stem nut when the valve is working. So that the gear speed ratio of the position indication mechanism in the electric device can be correctly selected. So that the position indication has enough accuracy to meet the observation of the opening and closing degree of the valve during the operation of the valve. Otherwise it is easy to cause illusion and affect the normal operation.