fuel tanker truck 1, foton brand 2,5000L capacity 3,material of tank :carbon steel fuel tanker truck , fuel truck , fuel tank truck , oil truck , ... in or out 3In order to ensure the tank pressure and atmospheric pressure are basically the same during their working , ... open ; when the tank pressure is lower than the outside pressure 3KPa , the real breathing valve would open FOTON 5T fuel tank truck