The biggest difference between the ball valve and butterfly valve is opening and closing part. Butterfly valve opening and closing member is a plate, and the ball valve is a ball.
Butterfly structure principle is particularly suitable for production of large diameter, butterfly plate of butterfly valve installed in the pipe diameter direction. Ball valve are usually suitable for not particles of impurities liquid, the loss of fluid pressure is small, ball valve has good sealing performance.
Characteristics of butterfly valves is open and close fast, simple structure, low cost, but the rigor and bearing capacityis not good. Ball valve is difficult to achieve large-caliber by volume and resistance limits. Ball valve seal is a long-term squeeze on the sphere of the valve seat, ball valve sealing usually use flexible material, it is difficult to use in high temperature and pressure pipe. Butterfly valve seal is a rubber as an intermediary, they are large difference in ball valve, gate valve metal seal performance. Opening and closing process of ball valve can operate by the force of both ends of the valve seat, the butterfly valve opening and closing is achieved to overcome the deformation of rubber, greater torque.