A ball valve is a common pipeline control device primarily used for opening, closing, or regulating the flow of fluids. It features a ball with a through-hole as its core component, which rotates to perform valve opening and closing operations. When the ball's through-hole is parallel to the pipeline axis, the valve is in the open position, allowing the medium to flow through; when the ball rotates 90 degrees so that the through-hole is perpendicular to the pipeline, the valve closes, preventing the medium from flowing.