GD high vacuum flapper valve is used to put through or cut off the airflow in vacuum pipeline. Applicable medium can be pure airnoncorrosive gases. According to its shaft seal structure, high vacuum flapper valve is classified into GD-J rubber shaft seal typeGD-J(b)bellows shaft seal type. According to its put-through type, it is classified into GD-J angle typeGD-S three-way type with prepumping.