What is the working principle of the air valve?

There are two types of air valves: single port air valve and double port air valve. The following takes the double-port air valve as an example to introduce its structure and working principle. (As shown below)

When the water pump is started and the valve body is not filled with water, the floating ball in the valve body falls due to its own weight, and the air holes are in an open state. With the increase of the starting working lift of the water pump, the pipe is filled with water, and the air can automatically release the air in the pipe. When the valve body starts to be filled with water, the float ball floats.

The air in the pipe and the valve body is completely released, and the valve body is filled with water; if the pressure in the pipe is higher than the atmospheric pressure, the floating float will block the exhaust hole under the pressure in the pipe, and the water in the pipe will not be discharged outside the valve.

During the operation of the pump, if the air dissolved in the water separates and accumulates in the air valve body, the floating ball loses its buoyancy and falls automatically. If the air volume is small, the floating ball of the small hole will fall to exhaust; if the air volume is large, the floating ball of the large hole will fall to exhaust. The falling drop of the floating ball reaches the balance between the pressure of the water pressure in the pipe and the gravity of the floating ball. After the exhaust is completed, the float returns to the position where the air hole is closed.

                    

More details of Air Valves, please go to https://www.mingpinmetals.com/Air-Valve-pl3707724.html