According to the standard of National Standard Petroleum Chemical Enterprise Design Fire-proof Rules (GB50160-90), the A and B series liquid fixed tank should have fire retardant and atoms valve. The atoms can maintain the pressure balance of the storage tank to prevent damage under super pressure and vacuum environment and reduce the validated and loss and meet the need of ventilated of the tank. The product has tense structure, large amount of gas, small amount of linkage and great sealed performance.

 

    

    Atmos valve is the key parts to protect the safety of the tank and it is stalled on the top of the tank. It was made up of pressure valve and vacuum valve. Under normal condition, it is used for protect the sealed performance of the tank and reduce the vapor loss. It can regulate the pressure of the tank and keep the safety of the tank.

   

    When the tank pressure is high tan the permitted pressure, the steam will link through pressure valve and the vacuum valve is closed. When the pressure is lower than the permitted pressure, the fresh air will enter the tank and the pressure valve is closed. The permitted pressure is regulated by the regulating plate weight.