Vertical steel tank with fixed roof and pontoon (РВСП)

Such tanks are often used for storage of crude oil, gasoline, kerosene, jet fuel. The pontoon is a rigid, gas-tight floating disk-shaped covering placed on the product mirror inside the cylindrical tank so that at least 90% of its area is covered.

The annular gap between the pontoon and the tank wall is sealed with a special rim seal. The pontoon is intended to reduce the rate of product evaporation and saturation of the gas-air space of the vertical tank by stored product vapors.