burst HsSo4 storage tank

[mjsamman]

we have a burst HsSo4 storage tank of about 93 % concentration. is it better to replace the tank or make new patch plate in the place of the burst.
is there any standard to convern this problem
thanks

 

[JStephen]

If it's a steel tank, API-653 addresses repair considerations.
It does not address economic considerations.
Best options would depend on the circumstances.

 

[MJCronin]

What type of tank is it ? "Flat bottomed" API-650 type ??

Can you take some pictures ?

Did the tank burst because of overpressure or because of ultimate corrosive failure ?

Concentrated H2SO4 is considered extreme corrosive condition for carbon steel. Ten to 12 years is a good life.... How old is your tank ?

Have you taken any UT measurements of wall thickness and compared these to the original conditions ???

What is the material and wall thickness of the connecting piping ? Does this need replacement ???

In my opinion, regardless of your ultimate course of action, it would be wise to get a few new tank cost quotes and estimates to delivery time ... Can't hurt ...

Regards

MJCronin
Sr. Process Engineer

 

[mjsamman]

Dear MJCronin

Down here you'll find the answers of your question [highlight #73D216](check attached file)[/highlight]

What type of tank is it ? "Flat bottomed" API-650 type ??
ASME VIII DIV.1 Ed. 2001 ADD 2003

Can you take some pictures ?
Attached

Did the tank burst because of overpressure or because of ultimate corrosive failure ?
Maybe becuse the vent is blocked

Concentrated H2SO4 is considered extreme corrosive condition for carbon steel. Ten to 12 years is a good life.... How old is your tank ?
H2SO4 93%, Less than 10 years old

Have you taken any UT measurements of wall thickness and compared these to the original conditions ???
NO.

What is the material and wall thickness of the connecting piping ? Does this need replacement ???
Carbon Steel, see attached specification

In my opinion, regardless of your ultimate course of action, it would be wise to get a few new tank cost quotes and estimates to delivery time ... Can't hurt .

[highlight #8AE234]As per shown attached picture of burst tank, the damage is not so big and could be repaired but which Code would govern this kind of repair. Your valuable consultation is highly appreciated.[/highlight]
[highlight #EF2929]Big thanks to you dear[/highlight]

 

[Dhurjati Sen]

Dear mjsamman,

I think you have got a clear picture of future actions after answering the above questionaire by MJCronin. This is the beauty of this forum and experts like MJCronin offer excellent guidance.

From the picture it seems that the repair would take a lot of time and resources. You need to follow API 510 for that.

It seems you have spare capacity and do not need this tank soon. Still, it is better to carry out a visual inspection and ultrasonic thickness survey for the tank at the earliest.

As a minimum, you would need to replace the top and bottom domes.

Regards.

DHURJATI SEN
Kolkata, India

 

[LittleInch]

It's a strange tank with the design code of a pressure vessel but no real design pressure other than hydrostatic head.

Does it have am ASME VIII plate on the side? If it does then it would probably need to be repaired and stamped R by an ASME VIII inspector.

But you really need to empty it, clean it and the pit and then do a full UT scan, especially of the welds and if possible take a few samples.

To break at a weld is bad news - it may be the weld metal and HAZ are corroding much faster.

I think you might be better cutting your losses and just buying a new tank, but why the ASME VIII code?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MJCronin]

Here is my suggestion on what you should do:

1) You seem to have enough information to get a budgetary grade estimate for a replacement tank. Get a cost estimate for a bare CS tank from the vendor that supplied the tank. Also ask for a number of weeks to delivery

2) Equipped with a cost estimate of a replacement tank, perform a random UT evaluation of the defective tank. The original wall thickness seems to be 8mm with a 3mm corrosion allowance. Pay particular attention to the shell-head juncture on both heads. Is there at least 5mm wall thickness left in the areas where you did the UT inspection?... Get an estimate to reweld the burst tank... Does the repair estimate exceed 50% of the cost of a new tank ?..... If it does, buy a new tank


3) Understand that you have a thin walled CS tank in Concentrated Sulfuric Acid Service and with no internal coating protection. A 7 to 10 year life would be typical for this application ....IMHO. Even if you found a way to repair this tank, you might find more problems in the OTHER HEAD of the tank in a couple of years..You should consider the cost of a new, internally coated CS tank and the long term plant advantages of reliable tankage

4) There are several types of internal coatings that were developed specifically to protect Carbon steel from sulfuric acid. I suggest that you also investigate the various types of coatings and what they would additionally cost for a new tank. I also suggest that you get an estimate of the new extended life of the tank from the coatings vendor

https://cmsolutionsus.com/pulp-paper-industry-maintenance/paper-mill-tank-repair-coating/

https://www.tnemec.com/projects/sulfuric-acid-tanks/

Then, based on the information you get above, the best course of action should be obvious...

Please keep us informed and complete this thread ..... Tell us of your final solution





MJCronin
Sr. Process Engineer

 

[MJCronin]

More good information here:

https://www.eng-tips.com/viewthread.cfm?qid=315366

https://www.eng-tips.com/viewthread.cfm?qid=152925

https://www.eng-tips.com/viewthread.cfm?qid=103747

MJCronin
Sr. Process Engineer

 

[saplanti]

I was not able to get the picture of the tank, however ıt is an industrial peactice that tank is to be designed in accordance with API 650 and manufacture in accordance with ASME VIII Div 1 for tha hydrostatic pressure of liquids. Therefore I would suggest you to follow API 653 requırements for repair.

 

[MJCronin]

Please respect us and complete this thread ..... tell us about your final course of action ....

MJCronin
Sr. Process Engineer