How does a ball valve work?

The working principle of a ball valve is to control the flow of fluid by rotating the ball. The main components of a ball valve include the ball body, valve seat, valve stem, and handle. When the handle rotates, the valve stem drives the ball to rotate, thereby changing the shape of the channel inside the valve body and achieving fluid on/off control. The valve seat of a ball valve is usually made of elastic material, which can ensure good sealing performance of the valve in the closed state. When the sphere rotates into contact with the valve seat, a seal can be formed due to the elasticity of the valve seat, preventing fluid leakage; When the sphere rotates to separate from the valve seat, fluid can flow through the channel inside the valve body.

The structural principle of a ball valve includes a sphere, a valve seat, a valve stem, and an operating mechanism. Spheres are usually spherical in shape, and channels are formed in the middle of the sphere to control the opening and closing of pipelines by rotating the sphere. The valve seat is a positioning device for a sphere, usually made of metal, plastic, or elastic material. It is a groove carved on the spherical surface of the sphere. When the sphere rotates, it cooperates with the valve seat to form a seal and prevent medium leakage. The valve stem is a shaft that runs through the center of a sphere, with one end connected to the sphere and the other end connected to an operating mechanism. By rotating or pushing the operating mechanism, the sphere is driven to rotate, achieving the opening and closing of the pipeline. The operating mechanism includes manual operating mechanism and automatic operating mechanism. Manual operating mechanism is usually composed of handle, gear, etc., while automatic operating mechanism is composed of electric motor, pneumatic mechanism, etc., which control the movement of the sphere through electrical or pneumatic signals.

Ball valves are widely used in pipeline control systems in industries such as petrochemicals, chemicals, power, water treatment, and papermaking due to their simple structure, good sealing, easy operation, low fluid resistance, and strong pressure resistance.