Design of Duckbill Check Valve
The simple, one-piece "duckbill" sleeve elimi-nates moving components and body structures that create problems with conven-tional check valve designs. There are no mechanical parts that can freeze, corrode, bind, or otherwise inhibit smooth operation. Unlike conventional check and flap gate valves, the Cla-Val Duckbill Check valve does not require regular maintenance to replace worn seats, hinge pins, balls, or flappers.
Operation of duckbill check valves
The principal of operation is simple. Upstream pressure in the valve forces the lips or "duckbill" apart to permit flow. As pressure or flow increases, the lips open further, allow-ing more flow. This feature allows solids to pass unhindered with low pressure loss. When there is backpressure or reverse flow, the lips squeeze tightly together, preventing backflow. Even with some wear, the "duck-bill" check sleeve will still function including sealing around entrapped solids.
