Check valves are mechanical valves that permit water to flow in only one direction, preventing process flow from reversing. They are classified as one-way directional valves. Fluid flow in the desired direction opens the valve, while backflow forces the valve closed.
These install near your skimmer or filter, so if the pump is turned off, it will not back-siphon and dry up.
Check valves will vary from photo. We use 4 different manufacturers. Some will be clear, some white, some black and some gray.
Also used to help with priming an external pump. Used on the intake to keep water in the pipe.
These are all Swing. Do not use Spring check valves in ponds. The pressure drop will be too great. Also the spring will clog with debris often.
