duckbill check valve water flood diffuser - The Rhinoflex duckbill check valves are an exceptionally reliable and a good, cost effective substitute for flap-gate valves and also other check valves. The easy one-piece design and reinforced rubber construction remove the mechanical and metal components that rust and seize in conventional flap-gates. These are generally custom made, one way , non-return check valves, made from various elastomeric rubbers, and built as reported by the application and also the line pressure and back pressure concerned. They are available in all standard pipe sizes, and typical application is back flow prevention and downstream of your pump, at pump stations.