Floating roof vs Fixed cone roof

[nsbreddy]

Our client is asking us to consider a floating roof instead of a fixed cone roof. I want some expert opinion on the forum what are the main factors to keep in mind for selecting a floating roof especially when the tank is for a cold temperature country like Kazakhsthan. Tank service is oil tank.

 

[LittleInch]

Floating roof tanks are good at reducing vapour losses from liquids with vapour pressure less than atmospheric. The country might be cold, but if the liquid is hot or volatile you can still generate large vapour volumes.

If you have large snow loads or high rain loads you might need a chine roof and an internal floating roof to stop it sinking.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[nsbreddy]

Thanks Littleinch, by the way what is chine roof? And economically, constructing a floating roof tank is cheaper or fixed roof?

 

[LittleInch]

Cone roof. Sorry that's what you get using predictive text....

Floating roof is more expensive for capital cost, but it's the vapour losses that usually require it, either financial losses or environmental damage.

CB&I made the first ones and they have plenty on their website if you want to read more.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[SNORGY]

Sandborn is another good source.

There are limitations on roof rise rate and fall rate for floating roof designs. These are intended to avoid hanging the roof up on its guide cables. I think it works out to about seven or eight feet of rise or fall per hour in a 2500 barrel tank, for example. This consideration puts upper limits on fill and evacuation rates.

 

[nsbreddy]

Thanks to all of you