A Breather Valve plays a vital role in preventing excessive pressure or vacuum buildup in sealed containers. It is also known as " Pressure Relief Valve, direct acting Pressure, Vacuum Relief Valves ". A special types of Relief Valves which are specifically designed for tank protection. These valves are installed in the tanks so that it can reduce the vapor loss through the vent nozzle.
It act as a protective device in atmospheric and low-pressure storage tanks. Like the normal breathing, breath valves also have inhaling and exhaling property and the in-breathing and out-breathing of the tank take place during the loading and unloading operations.
It is used to reduce the vapor loss from the storage tanks. It prevents accumulated pressure and the emptiness from the tank beyond the limit. Moreover it avoids inflammation. It includes a pallet and a diaphragm on the pressure and vacuum side of the valve. These two rest on an O ring seat to prevent any leakage. The pallet weight and the diaphragm weight pushes each other against the seat so it can remain closed. As a result, the pressure or vacuum increases and so that the pallet and diaphragm lifts and finally the air or gas is allowed to flow.