The duo check valve can be defined as the kind of valve which is used as the backflow prevention device. The backflow prevention is a process which is used to protect the supply of water from pollution or contamination. Based on the devices used for it, the backflow prevention can protect the portable water system from minor or even severe hazards. The duo check valves are also called as the double check assemblies. This is because these valves consist of two check valves in series which may be assembled with either a ball valve or gate valve.

Function of duo check valve

The function of the duo check valve is dependant on the two check valves. The check valve may be defined as the mechanical device which allows the flow of fluid in only one direction. These check valves are typically two port valves as they have two openings in them; one for the fluid to enter and the other one for the fluid to leave. A ball valve or a gate valve is installed at both the ends of the duo check valves for the purpose of separation or testing. Usually, very small ball valves are fitted in this position in order to fasten the testing equipment. This is done to test whether the duo check valves are still functional.

Applications of duo check valve

The duo check valve can operate at two separate conditions very effectively. First of all, during the normal flow of the fluid through it, the spring loaded check valve is opened in order to let the fluid flow. On the other hand, during the reverse flow, the spring loaded check valve closes in order to arrest the flow of fluid. As far as the applications are concerned, the duo check valve assemblies are very much appropriate for back siphonage and the back pressure related functions. But these valves are not preferable for the highly hazardous applications. The most common and general usage of the duo check valve is in fire sprinkler, lawn irrigation and for the use in combi boiler systems.