Duckbill Check Valves
Zero-maintenance rubber check valves for stormwater outfalls and backflow prevention. Self-cleaning design with no moving parts - simply install and forget.
DB-1 Duckbill Check Valve
DB-1 Duckbill Check Valve
DB-2 Flanged Duckbill Check Valve - AS2129 Table E
DB-2 Flanged Duckbill Check Valve - AS2129 Table E
DB-3 Inline Duckbill Check Valve - EPDM - Flanged
DB-3 Inline Duckbill Check Valve - EPDM - Flanged
Inline Duckbill Check Valve DB-4
Inline Duckbill Check Valve DB-4
About Duckbill Check Valves
Duckbill check valves are flexible rubber valves with a duck-bill shaped opening. When forward pressure is applied, the bill opens to allow flow. When flow stops or reverses, the bill closes to prevent backflow. They have no moving mechanical parts, making them maintenance-free.
Applications
Key Features
- ✓Zero maintenance - no moving parts
- ✓Self-cleaning design
- ✓Low headloss operation
- ✓Neoprene rubber construction
- ✓316 stainless steel clamps
- ✓Curved bill for tighter seal
- ✓Cracks open at 250mm head pressure, fully opens above 2m head
- ✓Prevents backflow and odours
DeWater supplies duckbill check valves in both flanged and insertable forms. Our inline duckbill check valve (the DB-4) fits inside the pipe and secures with an internal expanding clamp, ideal for retrofits and outfalls from 100mm to 600mm internal diameter.
How Duckbill Check Valves Work
Forward Flow
When water flows in the intended direction, the flexible rubber "bill" cracks open at around 250mm of head pressure and opens fully above 2 metres of head. The curved design provides maximum flow area with minimal headloss.
Backflow Prevention
When flow stops or reverses (such as during high tide or backwater conditions), the rubber bill closes and seals. The curved bill design provides 50% more sealing area than straight-bill designs.
Why Choose Duckbill Over Flap Gates?
Zero Maintenance
No hinges, no pins, no seals to replace. Duckbill valves have no mechanical parts that can corrode, jam, or wear out.
Self-Cleaning
The flexible rubber bill clears debris with each flow cycle. No accumulation of sediment or rubbish like flap gates.
Positive Seal
Rubber-to-rubber seal provides watertight closure even with debris present. No metal-to-metal contact issues.