Tank design life 4

[rab1944]

What resource can give me the process to determine the theoretical design life of an API 650 AST. Thanks for the guidance.

 

[Unotec]

Experience in the process it is going to be used, the environment, coatings and the maintenance, I think.

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[IFRs]

If you can establish a corrosion rate you can predict the life of the tank. With no corrosion it will last forever assuming no loads beyond design happen.

 

[rab1944]

Cool IFR. I am going to have to make assumptions and qualify them. Where can I get the basis for making the estimate. I remember this but the brain cells were in my last infarction.
Thanks and I look forward to your response.

 

[Bonswa]

Get a list of products and their assumed corrosion rates. We use them alot in catagory D piping where TML/CML locations are lacking. You can use the same principal to get you the corrosion rate that IFR mentioned. From there, plug it in to your T-MIN and MRT formulas and determine approximately how many years you can get out of it. Keep in mind though... THE FLOOR!!! Depending on your foundation type, you can have a much higher corrosion rate.

Like IFR stated, with no corrosion rate, it will last forever, so throw a liner under the tank, coat everything and maintain that coating at the manufacturers interval (10years usually). If you do that, as long as that coating is in good condition, you'll get no corrosion.

There's only one customer that i've done work for who has liners under every tank and takes their tanks out of service every 10 years, no matter what, just to refurbish the coating. That customer, has never had a single patch or weld repair required. Their thinking of it is this... they would rather budget to refurbish their tanks every 10 years rather than take them out every 20 years not knowing what to expect for repairs.

 

[IFRs]

API has a couple of documents that might help. You might wantt to try API 653 (inspection and repair), AP 597 (fitness for service) and API 580 and 581 (Risk based inspection) for starters.

 

[786392]

Dear IFR
Probably it is API 579(Fitness for service)assume typo?

Best Regards
Qalander(Chem)

 

[rab1944]

Thanks to all. I know how to proceed.