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Non code pressure vessel to to code conversion? 1

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dakotadreamer

Mechanical
Nov 8, 2012
1
Is it possible, under any scenario, for a vessel that was not designed and fabricated to BPVC VIII to be converted and stamped per code? If so, what would be the process?
 
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Unlikely. There are a significant number of in-process QA procedures that need to be followed. Inability to demonstrate them will likely make the process untenable.
 
Agreed, plus calcs, drawings, etc.

And good luck finding an AI willing to out on that limb...

Regards,

Mike

 
Absolutely agree. You cannot go back and attempt to code stamp a vessel without having proper documentation regarding design and fabrication history, along with no involvement from an AI.

Now, you can do an evaluation and show compliance with ASME code design, and convince a regulatory body to accept the vessel as a state special or request a variance.
 
MTR and NDE records must be signed by AI, as well as witness of the hydrotest, that will put the task very difficult. But I believe you can re-hydrotest and witness by AI.
 
I presume there's no provision for a 4x proof test on the thing in lieu of the calcs and QA, assuming conditions and size make success likely. If you're after a code MAWP/relief pressure of 25 psig and the thing has a calculated MAWP of 100 psig assuming the construction was done correctly, such a provision might come in handy if it exists. I know that this is sometimes accepted by local AIs for pressure piping components which don't have well established MAWP limits.
 
If you have the vessel itself, but don't have documentation of the building of it, you have no way of knowing whether the welding itself met ASME or not, among other things.

Some non-code vessels will use heads that are also non-code, typically with too small of a knuckle radius, and that can't be corrected.
 
I have a similar question:
If the vessel WAS designed and fabricated to BPVC III, but not tested, is it possible to test the vessel to obtain a U-Stamp in a state that is not governed by the NB (Wyoming)?
 
dentonous - if ALL of the in-process fabrication and inspection were done in accordance with the Code (including appropriate witnessing by the AI), and the ONLY thing missing was the final hydro (or witnessing of the final hydro), then it may be possible. Contact your AI for guidance.
 
If you are the Purchaser of the vessel and wish to U-Stamp it, the vessel would have to be made to the Code and thePurchaser's ASME Quality Manual. It is highly doubtful that the Purchaser can do so even if it has a U Certificate from the ASME; furthermore, why would the Purchaser want to assume the liability?

If you are the Manufacturer, it may be possible provided you can confirm that the vessel was designed and fabricated to the Code and in accordance with your Quality Manual subject to AI acceptance.
 
I think Metengr is exactly right. Once the vessel has been fabricated (completed), the only option is to perform evaluation documenting the vessel meets Code requirements and seek a State Special or Variance from the Jurisdiction where vessel is installed. If you were in a non-code jurisdiction, the vessel owner should seek guidance of his boiler & machinery insurance carrier.
 
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