When the medium flows in the specified direction, the valve is opened by the force of the medium: when the medium flows backward, the sealing surface of the valve and the valve seat is closed due to the self-weight of the valve and the role of the valve and the valve by the reverse force of the medium, to prevent the medium from flowing backward.

Counterclamp check valves are also known as backflow valves, backstop valves, backpressure valves, check valves. These valves are automatically opened and closed by the force generated by the flow of the medium itself in the pipeline.

The valve is a sphere, the outer surface layer of vulcanized rubber, the valve flap in the media under the action of the slide for up and down, so as to achieve the role of opening and closing.