The selection of electric control valve mainly needs to consider the following four factors:

1. The main control parameters of the electric control valve are: nominal diameter, design nominal pressure, medium allowable temperature range, flow coefficient, etc.

2 for the requirements of flow and open height into direct proportion of the strict occasion, should choose a special regulating valve. Ball and butterfly valve general coarse adjustment can be selected.

3. The sealing performance of the valve is one of the main indicators to evaluate the quality of the valve. Valve sealing performance mainly includes two aspects, namely, leakage and leakage. Internal leakage refers to the sealing degree between the valve seat and the closing part to the medium. Leakage refers to the leakage of stem packing, gasket and valve body caused by casting defects. Leakage is not allowed to happen.

4. The selection of the nominal diameter of the regulating valve shall be determined according to the required valve flow capacity. Regulator nominal diameter should not be too large or too small. Too large, increase the engineering cost, and the valve is in a low percentage range, the adjustment precision is reduced, so that the control performance is poor. If the valve is too small, it will increase the resistance of the system. Even when the valve is fully open, the system still cannot meet the set capacity requirements.