API 650 for small diameter tanks

[Franck L]

Hello everyone,

My client wants an API 650 calculation note for our tanks (wind, earthquake, transportation, anchor bolt, nozzle load...), as it was defined on tendering phase. However the tanks have a diameter of Ø700mm (height about 1 meter). I tried the best I could to issue such a calculation note but API 650 seems not applicable to such tanks... but I could not find anything to state that API 650 is indeed not applicable and do not issue the calculation note.
Does someone know if I can quote something from the Code that could exempt me from doing this? If not, does someone ever issued a calculation note for such small tanks and how could I proceed?

Thanks in advance.

Frank

 

[LittleInch]

That's just a small length of pipe.

Call it pipe storage instead of a tank.

700mm!

Has the client lost all sense of judgement?

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

 

[JStephen]

There's no reason it couldn't be done. You could work directly with ASCE 7 instead.

 

[JStephen]

One other thought- API-650 assumes a free-standing tank supported on a tank foundation. If the tank is supported by some other structure, or is in a building, you have some different rules in ASCE 7 that kick in.

The API rules limit the amount of product used to resist seismic overturn to a fraction of the contents, but on a small enough tank, this could reasonably be increased to essentially 100%. The API rules assume that frequency of the sloshing component is low enough to give a reduction in loading, and if this is not the case, you could treat the tank as rigid, without the sloshing- and this is one of the options in ASCE 7.

 

If you shrink an API storage vessel enough you end up with a 45-gallon drum.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[MJCronin]

What is the maximum operating pressure ?... API-650 has 2.5 psig.

How will you gain access to the inside of the tank ?

MJCronin
Sr. Process Engineer