Rubber duckbill valves

Rubber duckbill valves for drains and sewers provide end-of-pipe backflow prevention and flooding protection.

Rubber duckbill check valves which do not rust and are resistant to most chemicals found in wastewater. They do not block easily and are self clearing, so they have a long life span and require no maintenance, unlike traditional flap valves.

The choice of rubber check valve model depends on a number of factors.

The choice of rubber check valve model depends on a number of factors including location, connection design, hydraulic requirements etc. The mounting option for the same valve body shape and size has no bearing on the back pressure rating of the valve. We have over 30 years practical, real-world experience with rubber duckbill valves for drains and sewers.

Key Features

  • Low headloss maximises flow.
  • Flexible, durable rubber duckbill design.
  • Curved bill standard >450mm.
  • DN25 -DN2500 standard sizes.
  • Neoprene & EPDM standard construction.
  • Specials possible for clean water/potable water approval.
  • Slip-on or flange/backplate mounting available.
  • PN10, PN16 or other drilling on flanged valves.
  • 1 year warranty standard - 3 & 5 year available.
  • 25+ year design life


Dun Laoghaire-Rathdown County Council

Design Details

1240mm Tideflex TF-1 valve with thimble plate in angled headwall

The rubber duckbill valve is a revolutionary design for backflow prevention in drain and sewer systems for wastewater and stormwater drainage and recognised by the US EPA

Rubber duckbill valves consisting of a one-piece rubber matrix of numerous natural and synthetic elastomers and ply reinforcement, similar in construction to a truck tyre. These elastomeric check valves operate on differential pressure, using line pressure and back pressure to open and close, so no outside energy source is required. The vulcanised rubber duckbill design also means that these valves can be installed on vertical pipes.

The rubber duckbill valve has a low cracking pressure - weep flow starts from 25-50mm of differential water head - so the valve is self-draining. This eliminates standing water and maximizes storage volume (attenuation) in the upstream drainage system.

Rubber duckbill check valves are simple and reliable alternatives to ineffective drainage flap valves and tidal flap valves because they are constructed out of reinforced rubber. Therefore there are no moving parts that can corrode, warp or freeze. Rubber duckbill valves will handle large obstructions without jamming, and there is no gate to be stuck open or closed. This provides peace of mind for stormwater and combined sewer overflow systems designed to provide flood protection for low-lying areas due to sewer backup.

Rubber check valves are self-clearing of debris and seal tight around obstructions, which makes them an excellent choice for use as a tidal valve on coast / beach outfalls, river outfalls, marine outfalls and in floodplains. This also provides significant savings for sewer systems and treatment plants affected by saltwater intrusion.

Since rubber duckbill valves are normally closed, only opening with water differential pressure, they discourage unauthorised access to outfalls, especially on larger sizes. They are also silent in operation and there is no banging as experienced with traditional flap valves. This makes them ideal backflow prevention valves.

Rubber non-return valves are available in duckbill and inline models for easy retrofitting to existing drainage systems without requiring any modifications. Non-standard sizes  can be manufactured on request with the smallest possible being 12mm.

Drainage systems need to be reliable in the long term and meet the design intent 100% of the time, no matter the weather. Don't accept second-best when you cannot afford the consequences.

We stock over 700 rubber check valves to support installations with fast response and simple replacement of failed flap valves

Rubber check valves have been exposed to extensive independent hydraulic testing since the 1980s and continue to be improved through research and developments.

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