Stainless steel welded check valve refers to a valve that automatically opens and closes the valve disc based on the flow of the medium itself, used to prevent the backflow of the medium. It is also known as a check valve, one-way valve, backflow valve, and back pressure valve. Check valve belongs to an automatic valve, whose main function is to prevent medium backflow, prevent pump and drive motor from reversing, and prevent the release of container medium. Check valves can also be used on pipelines to supply auxiliary systems where the pressure may rise above the system pressure. Check valves can be mainly divided into swing check valves (rotating according to the center of gravity) and lift check valves (moving along the axis).