Storage tank conversion from EFVRT to CRVT

[mrengineers1010]

Hello Everyone,

We require tank conversion methodology, so that same can be vetted and approved.

job 1 : reducing tank height from 15 mtrs to 12mtrs
job 2 : converting roof from external floating roof to cone roof.

Can anyone post the methodology/detailed procedure for the above mentioned jobs please ?

 

[JStephen]

Is this one tank that you're reducing height and also changing to cone roof? Or two separate tanks, one lowered, one converted to cone?
Generally, details of this kind of work would be left up to the contractors doing the work, and might vary depending on tank size, access, surroundings, contractor's equipment and experience, etc. But generally:
1) Drain/clean/degas tank as required to make it safe for work
2) Perform complete inspection to make sure the tank is in good enough condition to justify the change
3) Perform engineering as required for emissions, wind loading, etc. Perform engineering as required for modification of stairs, etc.
4) Remove external floating roof piecemeal
5) Brace shell as required for construction stability; install scaffolding as required
6) Cut upper shell and windgirder off piecemeal
7) Add new top angle
8) Add new columns, beams, rafters, then roof plate
If this is two separate tanks, you wouldn't necessarily need to remove the windgirder prior to installing a cone roof.
More detail that this is generally going to come from contractors doing the work, based on actual tank details.

 

[mrengineers1010]

Hello Stephen,
thanks for reverting. more details as follows.
1. reducing tank height (from15mtrs to 12mtrs) and roof conversion(EFRVT to CRVT), both jobs to be executed on same tank.
2. 2 wind girder available which have to be replaced with a single wind girder at location specified by the designer.
3. API 650 tank
4. Client has asked for a detailed dismantling and erection methodology for the job. can you share any such documents, if available please. So it can be of help.

 

[HTURKAK]

Hello Everyone,

We require tank conversion methodology, so that same can be vetted and approved.

job 1 : reducing tank height from 15 mtrs to 12mtrs

I do not see the reason for reducing the height . Just limit the filling height for the new requirements. Regarding the new cone roof, i agree with JSTEPHEN.

 

[mrengineers1010]

I do not see the reason for reducing the height . Just limit the filling height for the new requirements. Regarding the new cone roof, i agree with JSTEPHEN.

Hi
Thanks for the suggestion, it helps but client however went with the query posted earlier.

 

[IFRs]

There are possibly commercial and or regulatory advantages to having a smaller tank rather than saying you are limiting the liquid level.

The methodology is basically remove 3 meters off the top, add an API suppored cone roof.
It's not rocket science, just basic tank work.
Get three bids from experienced tank contractors and understand their methods, equipment, cost and time frame.

It should be straightforward unless this tank is indoors or up on top of a steep hill without road access or underground or inside a tall concrete dike wall or surrounded by high power lines or inside a dike that you can't drive on, etc etc.

Call it maintenance or limited deconstruction.

Removing 3 meters of tank shell should be trivial for an experienced contracor or tank demolition expert.

The cone roof is similarly a reltively easy job, again go for bids on this with three experienced contractors, understand their methods and incorporate that into your documentation.

 

[mrengineers1010]

Do you have any documents that could assist in guiding us for the Dismantling and Erection part ? just for reference. If yes, can you inbox us the same ? it will help.

 

[IFRs]

API 653 and API 650, but you'll need to get your own copies.