Perfect designed internal floating roof storage tank is the best method to control the evaporation loss of the fixed roof tank.
Fixed roof and floating roof tanks.
Storage tank capacities and levels 15.
Double deck type floating roof 10 figure 1 6.
As with the internal floating roof tanks the function of the fixed roof is not to act as a vapor barrier but to block the wind.
Single deck pontoon type floating roof 9 figure 1 5.
Floating roof tanks are commonly protected against lightning ignition by bonding the floating roof to the seal shoes at no less than 3m 10ft intervals use of insulating sections in the hanging linkages covering sharp points on hangers with insulating materials and installation of electrical bond straps across each pinned hanger joint.
Fixed roof storage tanks.
A traditional and typical fixed roof storage tank consists of a cylindrical steel shell with a dome or cone shaped roof that is attached to the tank shell.
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.
Internal floating roof tank can be used to store gasoline jet fuel and other volatile oil and liquid chemicals like aldehydes alcohols methanol ethanol ketones acetone benzene benzene toluene xylene styrene.
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.
The roof rises and falls with the liquid level in the tank.
Domed external floating roof tanks usually result from retrofitting an external floating roof tank with a fixed roof.
It consists of an open topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid.
Single deck floating roof tank 12 figure 1 7.
The type of fixed roof most commonly used is a self supporting aluminum dome roof which is of.
Types of fixed roof tanks 8 figure 1 4.
The floating roofs can be either external i e with open top tanks or internal i e inside fixed roof tanks.
A pressure vacuum valve or breather valve is installed which allows the tank to operate at a slight internal pressure or vacuum.
Double deck floating roof tank 13 figure 1 8.
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.
