Check Valves
Check valves are very basic devices, yet they play a critical role in many pneumatic circuits. These valves are two-port valves that allow free flow in one direction while blocking flow in the other. They’re commonly employed in systems where backflow isn’t allowed. They can also be employed as a bypass valve, enabling media to flow around components that limit flow in both directions, such as needle valves.
Pneumatic check valves are constructed with a set cracking pressure, which is the lowest pressure necessary for the valve to operate and rely on airflow to work. These valves do not require help to open or close and will continue to work without the use of a manual operator, electricity, or other external controls since they are self-automated. Vacuum breakers, steam lines, cooling towers, HVAC systems, sump pumps, pressure pumps, boilers, and other applications all employ pneumatic check valves.