Also known as reverse flow valve, check valve, back pressure valve and one way valve. These valves open and close automatically with the force generated by the fluid flow in the pipeline and belong to an automatic valve. Check valves are used in pipeline systems. Their main function is to prevent media backflow, reverse pump and drive motor, and release of container media. Check valves can also be used to provide pipelines for auxiliary systems where pressure can increase more than system pressure. They can be divided into swing type (rotating relative to the center of gravity) and lifting type (moving along the axis).