What type of tank is characterized by a floating roof design?

A floating roof tank is designed with a roof that floats on the surface of the liquid stored within it. This design minimizes the evaporation of volatile substances by eliminating the space above the liquid and thus reducing emissions. The floating roof moves up and down with the liquid level, maintaining a consistent seal to the atmosphere, which is particularly beneficial for the storage of petroleum products and other volatile liquids.

This type of tank is an effective design for reducing the environmental impact of stored substances by preventing vapor loss. The open floating-roof tank, specifically, features a roof that is not sealed and allows for the vapor space above the liquid, which is managed during operations. This makes it distinct from options like the closed fixed-roof tank, which has a rigid, immovable roof that does not allow for vapor release.