The butterfly valve used for the electric butterfly valve of the butterfly valve shall meet those requirements: the butterfly valve used for the electric butterfly valve of the butterfly valve shall meet the following conditions: the radius of the butterfly valve shall be four times greater than the zero point of its height under the rated load; The additional stroke of butterfly valve shall be at least equal to 50% of the rated static deflection; The number of butterfly valve coils shall not be too small, generally not less than six;