Internal floating roof- does it affect wall thickness? 2

[Jay_]

Hello all,
Does the internal roof weight affect the wall thicknesses of an API 650 tank?
Should it be equivalent to a specified amount of liquid height in the tank when determining the thickness of the courses?


Detailing is a hobby,

 

[JStephen]

The floating roof displaces a weight of product equal to the weight of the floating roof. For a full-contact floating roof, the product depth will be greater in the rim space and in column/float wells than the height of the deck. Provided you monitor product level at those points, no further adjustment is required for the weight of the floating roof. See the attached sketch. Shell design is based on maximum product depth at point A, not floating roof depth at point B.

 

[IFRs]

I agree that the answer to the OP question is "no"

The weight of the floating roof displaces liquid which causes a perceptible rise in the liquid level and for a given tank size the liquid storage capacity (gallons or barrels) is reduced by the amount of product equal to the weight of the floating roof.

The liquid level will be higher than the deck just like the bottom of a canoe is lower than the water level of the lake it is floating in.

For a given weight of a floating roof, if the rim space were infinitesimally small the rise in liquid level in the tank would be no different than if the rim space were 25% of the tank diameter.

 

[Jay_]

Thank you guys!


Detailing is a hobby,