1920s Rivet tanks

Hi,

I have some planned inspections in a storage facility with 1920s aboveground storage tanks. The product storage its heavy crude.

Does anyone have experience in rivet storage tanks? If some one could give me some advices i will appreciate.


Im looking for some guidence besides API 653... some standards specific related to rivet joints old ones...

Does anyone have/know API 12A?


Thanks in advance...

Mac

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You can buy API 12F from API. API 653 does have limited guidance for riveted tanks.

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Thanks for the input.

I have API 12F ... but the propose was to know more about that type of construction. API 653 also refers to rivet joins repair... but its not the same as the construction code... of that time...

The closest think I have , as reference, it is API 12B ... but... its not the same...

The API 12A covers the intent... but the last edition was from 1951... i cant find it...

If some of you, from the old guard, has it and could spare a copy i will be grateful.

Thanks,

Mac

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That standard API-12A is available.

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I have extensive experience in repairing riveted tanks. They can be repaired just like a welded tank. A customer has started spraying poly urea on the riveted joints after repairs and it is working really well.
consider the riveted joint just like a welded joint. One thing to look out for is concrete floors with oakum cramed between the shell and the shrunk concrete. I have put annular rings and sketch bottoms on riveted tanks. There are some things you have to keep in mind especally as you weld near rivets. I weld 6 rivets on the horizontal away from any shell plate inserts. The riveted backing plate needs to be water stopped and the gap between the sheets need to be welded. I have the welders put a full pin weld at this gap welded on both sides. I have the riveted backer plate cut two rivet rows above the new bottom and seal welded.
If the tub ring is 5/8 all inserts can be grove welded with the top on the horizontal filet welded to the second ring and the inside overheaded and the rivet holes seal welded. Flush the rivets but DO NOT push them out!.
Installing manways full pin the tub and lap weld the second course. You have to be sure the manway inserts laps meet the requirements for lap patches on 653.
I do not understand why you would want to use 12A as a repair guide since 653 is what needs to be followed.
Here are some interior pictures of a recent project. This tank has a concrete floor with the oakum ring and fiberglass was laid 24 inchs up the shell and 4 feet on the floor from the shell.

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I agree that API-653 is what should be used. I would not rivet, but I would weld! This is a straight forward application with someone who has experience.

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I have has some clients want to do some crazy things but not rivet on a repair.
Most repair contractors are familliar with what needs to be done to repair riveted tanks with welded components.

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In regards to the inspection of the bottom of the riveted tanks, which method would you recommend to verify that the joints are not leaking?

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There is no way to know if it is leaking. The riveted floor should be replaced with a welded floor. I would never recommend a riveted floor be returned to service even with a double layer laminate system.Some owners in the past would put a double layer laminate however this requires the existing costing system to be removed. This usually uncovers why the laminate, concrete, gunniute, etc was put on the riveted floor in the first place.
The floor was rotten.
Putting in a new floor with properly designed leak detection, leak prevention barrier, CP and lining can extend the life of these tanks. II would NOT recommend upgrading the short 117 X 32 55M tanks as after you are through you only have around 30M usable. You can build a new tank for what the repairs would cost.
However if the tank is a 117 X 42-46 80M tank the tank can be upgraded for less cost than a new 80M tank.
Also alonf the Gulf Coast and overseas at old military installation there are 1930s era lap welded tanks usually erected by Wyatt Boiler Works.. You have to be careful about these and their location as the old lap welds HAZ is harder than Chinese arithmetic. If you have one of these treat it just like a riveted tank.

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Thank you for your comments and advice. I am a Mechanical Engineer working as an API 653 Inspector in Latin America. The particular case is a 1923 riveted tank, lapped joints, British construction, storing gasoline with an IFR. The internal inspection and MFL of the bottom show that the tank is suitable to continue in service, but a question arise in regards of how to assure that the bottom is not leaking could be a non visible leak. Is it a tracer gas and detector testing of the bottom an appropriated test for this case? What are the limitations of this type of test?

By the way, I found very funny your harder than Chinese Arithmetic which I never have heard before. Of course, I am not an English native speaker.

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I would vacuum box test with soap over the rivet joints in the floor if Mr BABRts suggestions are not possible.

I would expect a significant amount of crevice corrosion under the rivet heads and between the plates.

Three decades ago I used to do a hammer test on pressure vessels that had rivets to determine looseness or lack of bearing surfaces. It was successful and dependent on the evaluator, and it was replaced with UT shear wave and longitudinal wave techniques when they became cost effective for industrial applications.

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As a 653 inspector I will not recommend returning a riveted tank back to service with the riveted floor. Vacuum box testing the floor is difficult. You can sandblast the joints and visually inspect the joints and even do a vacuum box test. I would venture the guess the bottom is 3/16 thick instead of 1/4 inch.
However, if the customer is set on NOT installing a new floor, then the rivets and the riveted corner angle and the vertical lap plates need to be seam sealed and a hand laid double laminate system for the lining. If the floor has been MFE scaned the repairs need to be made. Most coating contractors are not capable of installing the hand laid laminate systems. Be sure the lining contractor has installed at least 20 systems and the field supervisor has installed and supervised at least that many systems.Then what you have is a lined tank that should hold.
Again, as the API Authorized Inspector you need to stress to the owner, returning the tank back to service is not prudent. A properly installed floor with a lining can extend the life of these tanks. Poly urea the shell laps on the inside and outside and a good paint job on the shell and you have another 20 years.

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Thanks for your valuable comments.

The bottom of the tank had a nominal thk of 5/16 in, British construction, and the minimum actual thk measured is about 0.250 in. The Owner is not considering to replace the bottom as it seems to be suitable to continue in service. I attach two photographs to illustrate.

It looks like it is not easy to perform vacuum box text of the joints in a reliable way. Any suggestion?

In regards of your statement regarding that the rivets, the riveted corner angle and the vertical lap plates need to be seam sealed and a hand laid double laminate system for the linning, is that a typical requirement in USA to those types of tanks? Or is an industry common practice? API 653 do not consider any requirement for riveted bottoms in fact there are little specific requirements for riveted tanks in the Code, if any. Is the sealant and the hand laid double laminate applied to cover only the joints and the adjacent area each side of them?

I will appreciate your input as this is new to me.

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One reason I have heard there is little on riveted floors as they are expected to be replaced as the tanks are inspected. Why repair what needs to be replaced?

While I am a little too young to have seen this done, the erectors would build a berm 6 to 8 inches higher than the edge angle and about 3 feet away from the shell and flood this with water. The space needs to be kept full of water and the seams observed.
Is this a good system?
Better than attempting to vacuum box the riveted seams.

If the owner is wanting to know if the floor seams are leaking. the answer is How the heck would You know? There is not a tank inspector I know who would give any type of qualification the floor has no leaks. This is imposiable. The owner is wanting to put the responsibility on your back. I have broad shoulder and a big butt, but I would never take that type of responsibility.
However, if owner has their mind set the floor needs to be blasted to a SSPC-SP5 White Blast. Do not use the CoPoxy shop primer to hold the blast and I guatantee there is no one in your world who can spray 2 mils. You get the hold primer too thick and the lining fails.
Use dehumidification.
Cover the floor laps patches pitting and anything that comes above the floor with Sherwin Williams Magnaplate Putty. Cover the shell rivets and backing plates with the stuff. Make a good cove of the putty in the corner angle. You do not want any right angles with the laminate system as this is where the lining will fail. Putty is cheap. Use plenty of it.
The laminate system can be either Magnaplate or Duraplate over the fiberglass matting. You will need to install two layers of the matting then a topcoat.
The riveted backing plates need to coated on both the inside and outside. There is good results with a poly urea system sprayed on the rivets.The rivets need to be coated on both the inside and outside. This keeps the rivets from leaking.

I would be sure the owner understands and you have it in WRITING there is absolutly no way as a 653 AI you can assure the owner the laps are and will remain leak free. The OWNER is responsible. The riveted tanks I have worked on the last 20 years have all been upgraded. In the early years 1993 to 1997 some owners would still patch but most would replace the floor. In all cases the floor would be lined with 2 layers for the repairs and 1 layer for the new floors.
What is the owners objection to replacing the floor? If the location has lax environmental laws, why even care if the floor leaks. But even with lax environmental laws the opportunity for a leak to cost money in the future is high.
If the owner only wants 2-5 years, then maybe putting the tank back in service and the tank leaking is OK

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I got off on a rant there, sorry.
If the owner decides to keep the riveted floor and install a reinforced liner, the entire floor and 24 inches up the shell needs to be lined.

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As an aside, if you wish to contact me via emai my address is curtis dot stewart @ yahoo dot com This is for the spam bots that roam the net. Just removedot add the period, lower case, no spaces.

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Again, thank you for your help. I will consider your advice with the customer. Thank you also for sending your e-mail for further assistance.

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Thanks to all for the your answers. The were very helpfull.

Best regards,

Mac

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Do you know of standards in effect around the 1910-1920 period for the design and construction of above ground, riveted tanks? Thanks.

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