The main difference between butterfly valves and ball valves is that the closure member of butterfly valves which is a plate while butterfly valves adopt a ball. Both disc of butterfly valves and core of ball valves rotate with their own axis. The disc of gate valves lifts with axis. Butterfly valves and gate valve can control flow by opening, while ball valves cannot be used for controlling flow. The sealing face of ball valves is sphere and the sealing face of butterfly valves is circular cylinder. Butterfly valves have the advantages of rapid on-off, simple structure and low cost. But butterfly valves have poor sealing and loading capacity. The characteristics of ball valves are similar to that of gate valves. Nevertheless, diameters of butterfly valves are limited by volumes and on-off resistance.
 
The structure is quite suitable for large diameter butterfly valves installed at horizontal direction. Inside cylindrical channel of butterfly valves, disc rotates with axis. Rotating angle ranges from 0 to 90 degrees. When disc turns to 90 degrees, the valves are opened completely. Butterfly valves have simple structure, low cost and wide range. Ball valves are suitable for liquid and gas without particle impurities, having less fluid pressure losses, good sealing and high cost. Compared with butterfly valves, ball valves have better sealing. The sealing face of ball valves is made of soft materials so ball valves cannot be used for high temperature and high pressure pipe. And sealing face of butterfly valves is made of rubber.
 
Ball valves operate under hold tight force on two seats during on-off. Butterfly valves should overcome the formation of rubber to realize on-off. The torque of butterfly valves is higher than that of ball valves.
 
Ball valves and plug valves belong to the same type of valves. Ball valves use ball as closure member. The ball rotates with centerline of body to on-off. Ball valves are used to cut off, distribute medium or change flow direction of medium.