API-12F no anchor bolt needed for tank?

[delagina]

I'm doing the foundation for a small tank, height is 7', diameter is 4".
I noticed there is no bolt center diameter for my anchor bolt.
The base plate O.D. is just 1/2" wider than the tank 0.D. so nowhere to put a bolt anywhere.

I called the vendor and was transferred to a supervisor and was told based on API-12F it does not need anchor bolts.
Is this supervisor correct?
I don't know anything about API-12F.

What if this tank is located in hurricane zone and/or elevated structure where wind is significant to overturn or slide this tank?

 

[racookpe1978]

Not as reliable, but will help. Could you use a series of clamp-down plates around the baseplate like a machine part is held on the milling table to keep the base from skidding sideways? If the tank really is 7 foot high x 4" dia means a "pipe clamp" type mount is really needed several places up the length of the tanks to an outside steel foundation. Then fasten the steel frame to the concrete pad below..

 

[r6155]

This storage tank is out of scope of AP1 SPEC 12F.

Regards
r6155

 

[racookpe1978]

7 foot high by 4 inch diameter is not a "tank". It's a pipe.

 

[r6155]

I think a mistake was made: diameter is 4 ft (1219 mm).
delagina, can you define it?

Regards
r6155

 

[mk3223]

It's correct that there is no anchors required for an API 12F tank. If there is a safety concern for the operation due to hurricane, wind, or earthquake, the straps may be added to hold down on the ground, or the tank may be fabricated per API 650 with required anchors.

 

[delagina]

Sorry for the typo. It's 4 ft diameter.

 

[JStephen]

It's a good question.
API-12F only covers certain standard sizes of tank. Your tank is not one of them, therefore, it's not covered by API-12F.
API-12F doesn't address anchorage. More to the point, it doesn't say anchors are NOT required, it just doesn't address anchors or wind or seismic loading at all. I think the philosophy is more like buying a 55 gallon drum, where neither the manufacturer nor the purchaser thinks to check it for wind or seismic stability. (Keep in mind, these are intended for oilfield use.) Generally, API-12F specifies the construction, but not design criteria.

In API-650, the design assumption is that the bottom plate does not resist any uplift due to pressure, and if anchor bolts are required, the holddown resistance of the bottom plate is not considered to reduce the anchor load. However, API-12F tanks are specified by API-12F to be adequate for pressures that will result in the shell lifting off the foundation. IE, design pressure uplift exceeds the weight of the shell and roof. So if you apply the API-650 criteria, then every API-12F tank will need anchors all the time due to design pressure.

I would suggest designing the foundation assuming an unanchored tank, neglecting effects of pressure uplift, and advise the owner that if they want to evaluate the tank for wind or seismic overturning, that needs to be done separately- either by your or by the tank manufacturer.

 

[r6155]

delagina
You can add 2 insert plates and do 2 fillet welds or tack welds, equal spaced, between bottom plate and insert.

Regards
r6155