There are several types of industrial check valves such as piston, ball, diaphragm, wafer and swing. The following video introduces the viewer to the inner workings of the swing check valve.
Check valves are used in many fluid systems such as those in chemical and power plants, and in many other industrial processes.
Check valves are also often used when multiple gases are mixed into one gas stream. A check valve is installed on each of the individual gas streams to prevent mixing of the gases in the original source. ”
The swing check uses the directional flow to push open a swinging disk. As long as flow continues, the disk stays raised. But as flow stops, gravity allows the disk to re-seat itself and any reverse flow is prevented by the closed disk. As reverse flow pressure increases, the swing check valves seating increases as well.