The duck bill valve is a non-return valve installed on drainage pipes to prevent backflow of fluid into the pipe system. Thanks to its one-way operating principle, it allows unobstructed flow of media in one direction with automatic closure when the flow stops.
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Duck bill valve (flap valve) is a non-return valve for drainage pipes that prevents backflow of fluid into the system and blocks the entry of birds and small animals. Easy installation, robust design. Available from DN 50 to DN 600, nominal pressure PN 6.
Flap valve
Features and benefits
Prevents backflow of fluid into the drainage system
One-way flow – opens by fluid pressure, closes by gravity
Protects the pipe system from the entry of small animals and birds
Easy installation at the end of the drainage pipe
Robust design suitable for permanent installation underground and in open spaces
Available for pipes from DN 50 to DN 600
Nominal pressure PN 6
Technical specifications and dimensions of the frog lid
| Do not notify | Diameter (mm) | l (mm) | Length (mm) | Angle (°) | Private |
|---|---|---|---|---|---|
| DN 50 | 60.3 | 100 | 70 | 15 | 6 |
| DN 65 | 76.1 | 100 | 90 | 15 | 6 |
| DN 80 | 88.9 | 200 | 112 | 15 | 6 |
| DN 100 | 114.3 | 200 | 140 | 15 | 6 |
| DN 125 | 139.7 | 200 | 175 | 15 | 6 |
| DN 150 | 168.3 | 250 | 210 | 15 | 6 |
| Day 200 | 219.1 | 250 | 280 | 15 | 6 |
| Day 250 | 273 | 250 | 350 | 15 | 6 |
| DN 300 | 323.9 | 250 | 420 | 15 | 6 |
| Day 350 | 355.6 | 300 | 490 | 15 | 6 |
| DN 400 | 406.4 | 300 | 560 | 15 | 6 |
| Day 450 | 457 | 300 | 630 | 15 | 6 |
| DN 500 | 508 | 300 | 700 | 15 | 6 |
| DN 600 | 610 | 400 | 840 | 15 | 6 |
Legend: DN = nominal diameter | D = outer diameter (mm) | l = connection length (mm) | L = total length (mm) | Angle = seating angle (°) | PN = nominal pressure
Frequently asked questions about the duck bill valve
What is a duck bill valve?
A duck bill valve is a type of non-return valve mounted at the outlet end of a drainage pipe. The name comes from its characteristic shape resembling a frog's open mouth – it opens under flow and closes automatically when the flow stops.
What pipe diameters is the duck bill valve available in?
The duck bill valve is available for pipes from DN 50 to DN 600, covering the range from municipal service connections to main collectors.
What is the maximum working pressure?
The frog cover is supplied as standard for a nominal pressure of PN 6.
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