A screwed ball float valve is a type of valve used for liquid level control in tanks and reservoirs. It features a hollow floating ball connected to a lever arm, which is attached to a valve body with screw threads for easy installation. As the liquid level changes, the float ball moves accordingly, opening or closing the valve to maintain the desired level. This design allows for simple and reliable automatic level control without the need for complex mechanisms. Screwed ball float valves are commonly used in water storage tanks, industrial applications, and plumbing systems for efficient and effective liquid level management.