Duckbill check valves, also known as rubber check valves

Duckbill check valves, also known as rubber check valves, are non-mechanical one way flow control devices that prevent backflow. They are a versatile and cost effective alternative to conventional flap gate valves. They are commonly used in sewage treatment plants, stormwater outfalls, effluent discharge, flood control and wet wells.

A duckbill check valve is an elastomeric component with a flexible sleeve that is designed to open or close depending on the pressure differential between the inlet and outlet sides of the sleeve. This allows media to pass and prevents backflow, reducing maintenance costs.

These check valves are available in a wide range of materials and sizes, including medical and food-grade silicone, liquid silicone rubber (LSR), hydrocarbon resistant fluorosilicone rubber (FVMQ), EPDM, Buna N & Nitrile Rubber, Neoprene / CR, Viton, etc. They are suitable for a variety of applications, and can be installed in a wide range of locations.

Some important factors to consider when choosing a duckbill check valve include material selection, installation method and angle of the end of the valve. These can all affect the slit close restoring force, which in turn, will affect how easily the valve opens and closes under certain pressure.

Inline rubber duckbill check valves are an ideal alternative to traditional flap-gate valves and can be fitted directly into a pipe or weir, or mate with a gasket metal flange for easy installation. They are also incredibly reliable and require no mechanical aid or operating assistance, making them an excellent choice for many applications.

They can withstand a greater degree of back pressure than flap-gate or swing/flap check valves, and are an effective surge relief valve that eliminates the build up of pressure surges in your piping system. They can also be fitted with a water hammer guard, which is a device that absorbs the energy of a sudden spike in the incoming pressure before it can cause damage to your piping.

Rubber duckbill check valves are ideally suited to a wide range of environments, from industrial applications to municipal and domestic water supply systems. They are corrosion-resistant and are available in a number of different sizes, with a range of flange options for ease of installation and connection.

This type of check valve is an essential part of a successful sewage system design, and is particularly useful for controlling the flow of incoming and outgoing water during periods of backflow. In addition to their ability to withstand back pressure, they are also extremely durable, and can be adapted to suit a variety of application conditions.

Inline rubber duckbill valves are a versatile and cost-effective alternative to traditional flap-gate valves, and can be fitted directly into a pipe, weir or tank. They are incredibly reliable and require no mechanical aid or operation, making them an excellent choice for many applications.

The slit close restoring force, which is the amount of pressure needed to crack the slit, is affected by the hardness and rebound resilience of the elastomer material chosen for the valve. In general, a material with higher hardness will have a better rebound resilience, which will ensure the slits of the rubber duckbill check valve can be closed under high pressure.