Fuel Oil Tank Maintenance Timing

[fcabreraenap]

Weeks ago I was assigned to the mission of assessing the efficiency of the tanks maintenance preocess in our refinery. After a first look, I think our maintenance times are very long, and the technology used is not the best.
I like to have your opinion in relation of the typical time required and the best technology to perform the following steps, in a floating roof fuel oil tank 55.000 bbls, 100' X 40':

1)Cleaning
2)Inspection
3)Repairs (Change of the 10% of the bottom, minor repair in shell and roof)
4)Hydrostatic Test

Thanks you

 

[MJCronin]

It has been my experience that:

1)Fuel Oil Tank Cleaning - depends on the frequency of water drainage and the quality of the fuel purchased. Perhaps once every 3-5 years

2)Inspection - Exterior "walk around" inspection - yearly. Detailed interior inspection: first one - three years after commisioning, then every five years

3)Repairs (Change of the 10% of the bottom, minor repair in shell and roof) - Depends on what is found during inspection

4)Hydrostatic Test - only one test should be done during commisioning

My opinion only

 

[fcabreraenap]

MJCronin, Thank you very much for your answer. But i think i dont explain well what i need. I need to know how much time takes and what technology use to every point, not the frequency.

regards

 

[Duwe6]

How big is your tank?
How clean is your fuel?
How efficient is your cleaning crew?
Do you have a multi-section 40-ft ladder that will fit through your manway, or will scaffolding need to be erected?

An Internal Inspx, without vacuum boxing the floor or MFL scanning, takes me about 3 hours. After the tank floor is mostly clean to bare metal, and ALL weld seams are down to bare metal. And the shell is clean and the first and last 10-ft [upper & lower shell] are bare metal, and there is a means to get up to the upper 10-ft of the internal shell and perimeter of the roof.

With a 'clean' nonwaxing fuel, this *can* be all done in 24-36 hours. But I have not seen it done this fast yet. With a LOT [3-ft / 1 m] of gummy residue, it can take well over a week.

 

[cloa]

The OP says what technology is needed? so he must be prepared to buy whatever is needed to do the job.

 

[fcabreraenap]

Thank Duwe6, its a fuel oil tank 55.000 bbls, 100'diameter X 40' height, and im looking to improve all the process using the best practices.
For example, for the cleaning im thinking in chemical cleaning, MFL and ACFM for inspections. I want the fourum opinion for every step:

1)Cleaning
2)Inspection
3)Repairs (Change of the 10% of the bottom, minor repair in shell and roof)
4)Hydrostatic Test

cloa, your are right.

 

[fcabreraenap]

Please, any one can help me?