Air System Check Valves
Air system check valves are available as single or double check valves.
Single check valves allow air to pass from a single source to its destination, but they won't let the air travel in the opposite direction.
Double check valves have two supply ports and one delivery port. The supply ports are connected to two different air sources, and the source with the higher air pressure sends air to the delivery port. Double check valves with a shuttle or disc should be installed horizontally.