(1) Forced sealing of the butterfly valve.
1) Elastic sealing butterfly valve: The sealing specific pressure is generated when the valve plate is pressed by the valve seat, the valve seat or the valve plate is elastic when the valve is closed.
2) External torque sealing butterfly valve: The sealing specific pressure is generated by the torque applied to the valve shaft.
(2) Pressure-filled sealing butterfly valve: The sealing specific pressure is generated by the pressure of the elastic sealing element on the valve seat or the valve plate.
(3) Automatic sealing butterfly valve: The sealing specific pressure is automatically generated by the medium pressure.
