Check valves are valves that automatically open and close the discs depending on the flow of the medium itself to prevent the flow back of the medium. They are also called check valves, one-way valves, counter-flow valves and back pressure valves. Check valve is an automatic valve, its main role is to prevent medium backflow, prevent pump and drive motor reversal, as well as container media release. Check valves can also be used to supply lines in which the pressure may rise to an auxiliary system that exceeds the system pressure. Check valves can be divided into swing check valves (with center of gravity rotation) and lift check valves (along the axis).
The function of this type of valve is to allow the medium to flow in only one direction and to prevent the flow in the opposite direction. Usually this valve operates automatically and the disc opens under the action of fluid pressure flowing in one direction; when the fluid flows in the opposite direction, the flow is cut off by the fluid pressure and the disc's self-coinciding disc acting on the seat.