Ball control valves have been adapted from the automation of simple on-off valves to automatic control valves designed specifically to accurately control the process. Ball control valve handles a rangeability of 300 to 1, notably higher than butterfly control valves that offer 20 to 1. They are also suited for slurry applications or those processes with fibrous content (such as wood pulp). The rotary action of the ball provides a shearing action against the seal, which allows for clean separation of the process during closure. Tight shut off is a characteristic of ball control valves, since the ball remains in continual contact with its seal.