When a ball valve is fully on, it is very free-flowing. Since the hole diameter is the same diameter as the pipe, no restrictions are present. This is not true for a gate or a butterfly valve. The internal components of these valves partially block the flow. According to Clarkson University, these free-flow characteristics mean ball valves are ideal for slurry feeds. Other valves would block the heavy particulates suspended in the liquids. The particulates will eventually pile up, and start blocking flow if other valves are used.
Clarkson University states when a ball valve is fully off, it has excellent sealing capabilities. Because the rotating ball seals tightly against the seat, it is an ideal valve for thin fluids like water. Furthermore, heavy slurries will not damage it, because the wiping action wipes particulates away from the face. With gate and butterfly valves, leakage is possible, especially if the valves are old.
Flow control is the ball valve's weakness. A ball valve should not be used for a trickle-on to full-on applications, since flow control is not precise. Controlling the flow from just a little on to fully on is called throttling. Engineers concur that a ball valve is not the best choice for throttling. One problem created is called choked flow. Choked flow occurs when the pressure drops or rises suddenly, and leads to internal pipe damage. For throttling, other types of valves should be used. A ball valve should only be used for a full-on or a full-off application, like an on-off switch for a light.