Flange Type duckbill check valve

Flange type Rubber Duckbill Valves, widely used in the demanding applications of many industries, are precision-molded, one-piece elastomeric valves that provide reliable backflow prevention at low pressure differentials.  Rubber Duckbill valves allow free flow with positive differential pressure.  

Normally Open one-way check valves

Prevents backflow leakage when minimal backpressure is applied

Can be installed easily into hole and sealed by compressing flange