Water valves are unique, onepiece, elastomeric components that act as backflow prevention devices or oneway valves or check valves. They have elastomeric lips in the shape of a duckbill which prevent backflow and allow forward flow. 
 
The main advantage of duckbill valves over other types of oneway valves is that duckbill valves are self contained i.e. the critical sealing function is an integral part of the one piece elastomeric component as opposed to valves where a sealing element has to engage with a smooth seat surface to form a seal. 
 
Therefore duckbill valves are easily incorporated and assembled into a wide variety of devices without the hassle or problems associated with the surface finish quality of mating seats and/or complex assembly processes.

One way valves are used for controlling the direction of flow of a fluid. Designs can include umbrella valves, duckbill valves,  Belleville Valves and diaphragm valves etc.

One way valves can be designed to provide the customer's required head loss and flow rate for particular applications.

A range of materials and designs are available to handle different fluids and service conditions.