Brady check valves are for use in nearly every water well/irrigation system imaginable. The main use is to prevent water pumps from losing their prime. This is the main cause of pump failure. They can be used in vacuum systems as well as any other application where backflow prevention is desirable. Brady check valves utilize a unique, patented internal design which allows up to 50% more flow than ordinary check valves. Made of high strength acetal polymer, they are noncorrosive, environmentally safe, and will outlast most metal valves.