A check valve is a device that allows fluid to flow only in one direction. They have two ports, one as the fluid inlet and the other as the fluid outlet. They allow fluid to flow in only one direction, so they are often referred to as "check valves", and the main function is to prevent backflow in the system.
The check valve relies on the differential pressure, and it requires a higher pressure on the input side than on the output side to open. The valve will close when the output pressure is high (or the input side pressure is not high enough). The closing mechanism varies according to the type of valves. Unlike other valves, they do not require handles, levers, actuators or staff to operate.
They are usually installed in equipment where backflow can cause problems. Check valves are cheap, effective and simple ways to solve potential problems.
The contaminated backflow can contaminate the upstream medium, which is a big problem. For example, it can ensure that waste can leave and will not re-enter the system as long as the sewage pipe has a check valve. In addition, this method can also be used if the backflow will cause damage to upstream equipment that only allows the medium to flow in one direction. For example, a reverse osmosis filter can only allow water to pass in one direction. Therefore, a check valve installed downstream can prevent the issue. Currently, check valves are available in various sizes, designs and materials so that they can be adapted to every type of equipment.