Ball Check Valves
A ball check valve is a type of check valve in which the movable part is a spherical ball. Ball check valves are used in spray devices, dispenser spigots, manual and other pumps, and refillable dispensing syringes. Ball check valves may sometimes use a free-floating or spring-loaded ball.
Ball check valves are generally simple, inexpensive metallic parts, although specialized ball check valves are also available. For example, ball check valves in high-pressure HPLC pumps used in analytical chemistry have a ball of synthetic ruby, a hard and chemically resistant substance.
A ball check valve is not to be confused with a ball valve, a quarter-turn valve similar to a butterfly valve in which a ball acts as a controllable rotor.