A check valve, is a type of valve, a one-way flow control valve or non-return valves, as commonly known in industry. It is a mechanical device with two ports, allowing flow of gas or liquids in one direction only, and opposing the flow in the opposite direction, this is always indicated with a directional arrow.
How does a check valve work?
Check valves are flow sensitive and work to open if the upstream pressure is greater that the seat release presser. The internal seat, spring force or disc allows flow to pass forward, which opens the valve. The seat begins closing the valve as forward flow decreases or is media is reversed, depending on the design.
What are the parts of a check valve?
The construction of a check valve is normally simple with only a few components such as the body, seat, disc, and cover. Depending on design, there may be other items such as a stem, hinge pin, disc arm, spring, ball, elastomers, and bearings, and some valves have a very specific opening pressure, and is application dependent.
What are the uses/applications of a check valve?
The main uses of check valves are to prevent back flow of media. Some other applications where they are used in industry are; feed water control systems, dump lines, make-up water, miscellaneous process systems, nitrogen systems, monitoring and sampling systems.