Marine flange duckbill valve seawater corrosion resistant 0.1Bar low pressure start-up export-grade quality assurance

A flange duckbill check valve is a type of check valve that features a unique, flexible, and non-mechanical design, resembling a duck's bill. The "flange" in its name refers to its connection type, meaning it's designed to be bolted between two flanges in a pipeline system.

What it is the flange duckbill check valve?

Design: The core of a duckbill check valve is a one-piece, flexible elastomeric body, typically made from rubber (like Neoprene, EPDM, Natural Rubber, Buna-N, Viton, etc.). This sleeve is shaped like a duck's bill at one end, forming a slit that acts as the valve's opening and closing mechanism.

How does flange duckbill check valve work:

Passive Operation: It's a completely passive device, meaning it requires no external power source (electricity, air, etc.) or manual intervention to operate. It relies entirely on the fluid pressure differential.

Forward Flow (Opening): When there is sufficient forward pressure from the fluid in the pipeline, it pushes against the "bill" of the valve. This pressure causes the flexible lips of the duckbill to open or "flex" apart, allowing the fluid to flow through. As the pressure or flow rate increases, the opening widens, minimizing head loss.

Backflow Prevention (Closing): When the forward flow stops or reverse pressure (backpressure) occurs, the pressure on the outside of the duckbill (or the lack of forward pressure) causes the flexible lips to squeeze tightly together. This effectively seals the valve, preventing any backflow of fluid. The greater the backpressure, the tighter the seal.

Flanged duckbill valve connection data

Flange type duckbill valve assembled and shipped

Uzbekistan customers ordered a batch of DN300 PN10 stainless steel flange duckbill valves for use at the seaside

Flanged duckbill check valves are widely used in demanding environments where reliable backflow prevention is critical, especially in:

Wastewater Treatment Plants and Sewage Systems: Preventing backflow in sewers, sludge lines, and effluent discharge.

Stormwater Outfall Systems: Managing stormwater discharge into rivers, lakes, or the ocean, preventing tidal or river backflow into drainage systems.

Flood Control: In flood mitigation systems, pump stations, and drainage systems for airports, roads, and shopping centers.

Submerged Outfall Diffusers: Ensuring one-way flow in underwater discharge pipes.