Ball valves and butterfly valves are common types of industrial valves used to control the flow of fluid media. They have some differences in structure and working principle. The differences between ball valves and butterfly valves will be introduced in detail below.

1. Structure and working principle 1. Ball valve: Ball valve is composed of valve body, ball, valve seat, valve stem, sealing ring and handle. There is a ball inside the valve body, and a hole is opened in the ball. The flow of the medium is controlled by rotating the gap between the ball and the valve seat. When the ball is aligned with the hole in the valve seat, the medium can pass; when the ball rotates 90 degrees, the hole is not aligned with the valve seat, and the medium is cut off. The valve stem is rotated by the handle to rotate the ball, thereby controlling the fluid.

2. Butterfly valve: Butterfly valve consists of valve body, butterfly plate, valve stem, sealing ring and handle. The butterfly plate is located inside the valve body and is connected to the handle through the valve stem. The butterfly plate usually has a section of holes, and the flow of the medium is controlled by rotating the butterfly plate. When the hole of the butterfly plate is aligned with the valve body, the medium can pass; when the butterfly plate rotates to 90 degrees, the hole is perpendicular to the valve body and the medium is cut off. The valve stem is rotated by the handle to rotate the butterfly plate, thus controlling the flow of fluid.

2. Fluid flow characteristics 1. Ball valve: The fluid flow characteristics of ball valves are rapid opening and closing, and small fluid resistance. The valve core hole diameter of the ball valve is basically the same as the diameter of the pipe, so the valve core has very little resistance to the fluid when fully open and fully closed. In addition, because the ball valve seat and valve core are usually made of metal and have good sealing performance, the ball valve has better sealing performance.

2. Butterfly valve: The fluid circulation characteristics of butterfly valve are small flow resistance and small pressure drop. When the butterfly plate rotates in the valve body, the flow direction of the fluid will change, causing a certain resistance and pressure drop. The cross-sectional area of the butterfly plate is inconsistent with the cross-sectional area of the pipe, so a certain flow loss will occur. In addition, the sealing performance of butterfly valves is worse than that of ball valves, especially under high temperature and high pressure, and leakage problems are prone to occur.

3. Scope of application and application scenarios 1. Ball valve: Ball valve is suitable for small and medium-diameter pipelines and is widely used in petroleum, chemical industry, metallurgy, electric power and other industries. The ball valve is simple to operate, has a small rotation angle, and is easy to realize automatic control. The ball valve has good sealing performance when under pressure and is suitable for high temperature and high pressure pipeline systems.

2. Butterfly valve: Butterfly valve is suitable for large-diameter pipelines and is widely used in sewage treatment, food processing, air conditioning systems and other fields. The butterfly valve is small in size, light in weight, easy to install and saves costs. The butterfly valve has a fast switching speed and is suitable for some scenarios that require fast cutting off of the medium.

In short, there are certain differences between ball valves and butterfly valves in terms of structure, working principle, fluid flow characteristics and application scenarios. When choosing to use it, you need to decide which valve to use based on specific working conditions and engineering needs.