Abstract: An improved bracket assembly for a floating roof tank comprises a primary seal element and an auxiliary seal element placed above the primary seal element. A spring-tensioned rolling element, such as a wheel, is placed above the auxiliary sealing element in spaced relationship thereto. The rolling element is inclined with respect to the vertical wall of the tank at an angle of 10 to 60 degrees, thereby assuring a continuous and constant contact of the rolling element and of the auxiliary sealing element with the inside wall of the tank and substantially preventing the escape of vapors from the tank.