Check Valve is a directional control valve in which airflow can only flow in one direction and cannot flow in the opposite direction. It works the same as a hydraulic Check Valve. Compressed air enters from port P, overcomes the spring force and frictional force to open the valve port of the one-way valve, and the compressed air flows from P to A; when there is no compressed air at port P, under the action of the spring force and the residual air force of port A (cavity) ; The valve port is closed, so that the air flow from A to P is blocked.
