Air Vent (Automatic Air Venting) (Animation)
When liquid is pumped through the system, the initial air inside the piping is pushed into the air vent by the pressure of the flow. The float stays at its lower position and the valve is fully open, allowing the air that enters the air vent to be pushed around the float and discharged.
After the initial air venting, the liquid flows into the air vent. The float rises with the rising liquid level and closes the valve.
If air enters the air vent while it is closed, the liquid level drops and the float lowers to open the valve and discharge the air. When liquid flows into the air vent again, the float will rise to close the valve.
