The all-weather breathing valve is installed on the top of the storage tank to solve the positive and negative pressure in the tank, so that the liquid in the tank is not obstructed. When the external liquid is input into the tank, a large amount of gas is exhaled (called positive pressure).  For example, when the liquid in the tank is exported out, the inside of the tank must be sucked into the tank from outside air (called negative pressure).  If the breathing valve is automatically closed when the work is stopped, the liquid and gas in the tank will not leak out, so that the quality of the liquid in the tank is advantageously guaranteed.