Check valve characteristics
A check valve is a directional control valve in which the airflow can only flow in one direction and cannot flow in the opposite direction. It works like a hydraulic check valve. The compressed air enters from the P port, and the valve port of the check valve is opened against the spring force and the friction force, and the compressed air flows from P to A; when the P port has no compressed air, under the action of the spring force and the residual force of the A port (cavity) The valve port is closed, so that the airflow from A to P is blocked. The check valve is applied to the case where the reverse flow of the air flow is not allowed. For example, when the air compressor is inflated to the gas tank, a check valve is arranged between the air compressor and the gas tank, and when the air compressor stops working, the gas tank can be prevented. The compressed air in the air is returned to the air compressor. The check valve is also often combined with a throttle valve, a sequence valve, etc. into a one-way throttle valve and a one-way sequence valve.