Check valve is a valve in which the opening and closing member is a circular valve flap and acts on its own weight and medium pressure to block the reverse flow of the medium. It is an automatic valve, also known as a check valve, non return valve or isolation valve.

A ball check valve is a check valve in which the closing member, the movable part to block the flow, is a ball. In some ball check valves, the ball is spring-loaded to help keep it shut. For those designs without a spring, reverse flow is required to move the ball toward the seat and create a seal.

The swing check valve is also called a check valve or a check valve, and its function is to prevent the medium in the pipeline from flowing backward. The valve of the opening and closing member is opened or closed by the medium activity and force to prevent the back flow of the medium.

The gate valve refers to the valve that the closing part (gate) moves vertically along the channel axis. It is mainly used as the cutting medium in the pipeline, that is, it is fully open or fully closed.Check valve is automatically to open and close via media pass through.