What type of roof is this?

[Cristian N]

Could anyone clarify what type of roof this is?
Yes, it is an external floating roof. It has pontoon compartments on the outer rim and the center compartment that protrudes upward.

 

[JStephen]

I find one on this page, but no special name for it- apparently a center pontoon:

http://www.astanks.com/Tanks/T_EN/Stiffening_pontoons_EN.html

 

[Geoff13]

Very odd. I've never seen this before.

The "socked" pipes make me wonder if this is an area to "catch" a vapour flash, and then release it through the "socks". The socks could limit day-to-day emissions (poorly) but allow large gas volumes out occasionally. Let me stress this is purely a W.A.G.

Hopefully there's someone on the forum from the company that makes this style of floating roof.

 

[Cristian N]

The sleeves are for the floating roof legs which were in the high position when this picture was taken. I believe it has to do with the local jurisdiction emission guidelines.

Also , could you elaborate on what W.A.G. means?

 

[Geoff13]

Looking again I now see the socks on the outer legs. Back to square one.

Wild A** Guess

 

[IFRs]

Tee top deck plate is continuous. To me that makes it a double deck floating roof with an unusual center pontoon. The top deck seems to have a significant slope at the outer edge and then less of a slope in the middle. It's possible that the double deck thickness gets quite thin at the center, suggesting that the center pontoon is required for high snow or rain loads. I suppose it's possoble that it is a single deck floater with an annular pontoon under the top deck but that would be most unusual as the single deck would be above the product in places but it would explain the need for a center pontoon. It does seem like an odd duck, we'd all be interested what you find underneach...

 

[Cristian N]

IFR,

You are correct, there is certainly a annular pontoon underneath the top deck on the outer section of the roof. I am certain when I reach the center plates though, I am standing directly over the product. I'm assuming this was the need for the center pontoon.

 

[IFRs]

That sounds like a peculiar deck in that the center deck would be out of the liquid at the inner edge of the pontoon ring. This would put it under cyclic stress from landing. The deck would also not be full-contact. I remain curious to see what you find underneath.

 

[JedClampett]

Check with EIMCO.

 

[IFRs]

Jed - Not sure I see anything on the EIMCO link - can you be more specific?