Ball valve is a form of quarter-turn which uses a hollow, perforated and pivoting ball to control flow through it.
Ball valve opens when the ball's hole is in line with the flow and closed when it is pivoted 90-degrees by the valve handle. The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed, making for easy visual confirmation of the valve's status.
Ball valve is mainly used to control the flow of fluid on the pipeline, that is partially or filly open or close.
Ball valves could be used in different temperature and pressure depending on the process condition and could be used for a variety of different fluid depending on the valve material.