Floating roof tank can be divided into two types internal floating roof and external floating roof.
Fixed roof and floating roof tanks.
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.
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.
Fixed roof storage tanks.
Storage tank capacities and levels 15.
The roof rises and falls with the liquid level in the tank.
Single deck pontoon type floating roof 9 figure 1 5.
Double deck type floating roof 10 figure 1 6.
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.
Single deck floating roof tank 12 figure 1 7.
Perfect designed internal floating roof storage tank is the best method to control the evaporation loss of the fixed roof tank.
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.
Types of fixed roof tanks 8 figure 1 4.
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.
Domed external floating roof tanks usually result from retrofitting an external floating roof tank with a fixed roof.
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.
It consists of an open topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid.
The type of fixed roof most commonly used is a self supporting aluminum dome roof which is of.
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.
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.