Floating Roof Fixed Roof Tank

Floating roof tank can be divided into two types internal floating roof and external floating roof.

Floating roof fixed roof tank.

An internal floating roof tank is a floating roof tank fixed an extra fixed roof on the floating roof to prevent floating roof from wind and rain and guarantee the quality of the stored oil. Of currently used tank designs the fixed roof tank is the least expensive to construct and is generally considered the minimum acceptable equipment for storing liquids. The floating roofs can be either external i e with open top tanks or internal i e inside fixed roof tanks. Tanks with external floating roofs are used primarily to contain liquids with high vapor pressures when the vapor emissions from fixed roof tanks would exceed the standards set by the local jurisdiction.

Floating roof tanks are generally about twice as expensive to construct as fixed roof tanks so there is a trade off of risk against cost. However by reducing emissions the increased costs can be offset or justified on the basis of reduced product loss though evaporation a product savings and less impact to the environment. A typical fixed roof tank consists of a cylindrical steel shell with a cone or dome shaped roof that is permanently affixed to the tank shell. The internal floating roof in a fixed roof tank with ifr design must float on the liquid surface except when the floating roof must be supported by the leg supports.