The Difference Between Butterfly Valve And Ball Valve

The biggest difference between Lined Butterfly Valve and ball valve is that the opening and closing parts of butterfly valve are a plate, while ball valve is a ball. The valve plate of butterfly valve and the valve core of ball valve rotate around their own axis. Butterfly valve can adjust the flow rate by opening degree, but ball valve is not easy to do this.
The characteristics of butterfly valve are fast opening and closing speed, simple structure, low cost, but poor tightness and pressure bearing capacity. The characteristics of ball valve are similar to those of gate valve, but it is difficult to achieve large diameter due to the limitation of volume and opening and closing resistance.
The structural principle of butterfly valve is particularly suitable for making large-diameter valves. The butterfly plate of butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When it rotates to 90°, the valve is fully open. It has simple structure, low cost and large adjustable range. Ball valve is usually suitable for liquid and gas without particulate impurities, with small fluid pressure loss, good sealing performance and high cost. In comparison, the sealing of ball valve is better than that of butterfly valve. The ball valve seal relies on the long-term compression of the valve seat on the spherical surface. It will definitely wear faster than the hemispherical valve. The seal of the ball valve is usually made of flexible materials, and it is also difficult to use in high-temperature and high-pressure pipelines. The butterfly valve seal uses rubber as an intermediary, and its performance is far different from the metal hard seal of the hemispherical valve, ball valve, and gate valve. After long-term use of the hemispherical valve, the valve seat will also produce slight wear. It can continue to be used through adjustment. The valve stem and packing only need to rotate 90° during the opening and closing process. When there is a sign of leakage, tighten the bolts of the packing gland a little to achieve no leakage at the packing. Other valves are still barely usable for small leaks, and the valves are replaced for large leaks.
The ball valve operates under the clamping force of the valve seats at both ends during the opening and closing process. It has a larger opening and closing torque than the hemispherical valve. The larger the nominal diameter, the more obvious the difference in opening and closing torque. The opening and closing of the butterfly valve is to overcome the deformation of the rubber to achieve, and the torque is greater. The gate valve and stop valve have a long operation time and are laborious.
Ball valves and plug valves are valves of the same type, except that the closing part is a sphere, which rotates around the center line of the valve body to open and close. Ball valves are mainly used in pipelines to cut off, distribute and change the flow direction of the medium.