Clamp duckbill check valve 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. Duck check valve allow free flow with positive differential pressure. With negative differential pressure, backflow is checked. Pressure drop across the valve is a feature unique to check duckbill valve They can be designed to operate in a few millimeters (inches) of water to several hundred kPa (psi), depending on valve size, geometry and compound characteristics. Duckbill Check Valves are also designed to start functioning at specific opening and closing pressure ranges, depending on your specifications. Features: Reliable backflow prevention 100% elastomeric construction eliminates maintenance Will not corrode, warp or freeze open or shut 1”-2” Cracking Pressure, Low Head loss Custom built for each application based on pressure and flow conditions Note: 1. The inner diameters are matched to the pipe outer diameter on which installed. 2. The weight is approximate. 3. The usual material of the clamp is stainless steel 304, other material availble upon request. 4. Duckbill valves of dimensions in the above table are available in inventory. Any other dimensions and designs available upon request. We love hearing from our customers and value your feedback.Here are ways to contact us, 24 hours a day, 7 days a week.Email: Sales@flexible-joints.com, web: www.flexible-joints.com