Abstract: An explosion-protection and extinguishing safety device for inflammable liquid storage tanks. An aperture of a predetermined size located on the top of a tank is controlled by a switch device of an automatic switching system. The switch device of the aperture is closed under normal conditions and automatically opened when the internal pressure of the tank or the temperature of the wall of the tank is above a preset value. Application of heat to the tank results in vapor discharge to prevent explosion of the tank. The discharged vapors are burned above the aperture to eliminate external accumulate of the inflammable vapors.