R-stamp required, or Corrected Copy of U1A? Vessel has not left manufacturer facility 1

[Hurmanetar]

Pressure vessel fabricator has 4 pressure vessels that were fabricated 2 years ago. U1As signed off and submitted. Customer did not want to take delivery so they never left the fabrication facility. Now the customer wants to lower the MDMT form -20 to -40 which will require the manufacturer to cut off and replace the nozzles with SA-333 Gr 6 pipe and SA-350-LF2 flanges.

Somewhere I had read that ASME VIII div 1 code applies up until the vessel leaves the manufacturer's facility and if any alteration is made after that point it would be under NBIC and require R-stamp (if required by the jurisdiction or insurance).

But if the vessel has not ever left the OEM facility, could the alteration be made by the OEM, then re-hydro, AI inspect, and then submit a corrected copy of the U1A? I cannot find a time limit on submitting a corrected copy of the U1A.

 

[metengr]

If ASME vessels are completed - stamped with data reports signed regardless of location, any new repair or alteration work would be under the NBIC or API 510.

 

[oknow]

My opinion is the same as Metengr. What did your AIA say?

 

[r6155]

If the new PV was never put into service it is still a new PV.
My opinion only.

Regards
r6155

 

[Hurmanetar]

Metengr, where can these definitions be found? I know I read once that if the OEM still owns the vessel because it hasn't left the shop yet, then the vessel is still under the code of construction rather than the NBIC, but I cannot find where I read that.

Another similar situation but instead of 2 years going by between completion and alteration it happened immediately:
A vessel was supposed to have 600# flanges and 600# flanges were called out on the ASME calculations, but a drawing BOM error called out 300#, so the vessel was built with 300# flanges. The vessel was hydrotested to 1040 PSIG for 800 PSIG MAWP (645 PSIG is max permissible for 300# flanges at 350 F), and U1A signed off by AIA who also missed the error, so U1A showed 300# flanges and 800 PSIG MAWP @ 350F which is obviously wrong. The error was discovered before the vessel shipped, so the flanges were cut off and replaced with 600# as originally called for by the calculations. Vessel was re-hydro tested and inspected again by AIA. So same question again in this case, can a corrected copy of the U1A be issued, or is an R-stamp required?

I have not yet asked our AIA about this, but I think he is supposed to be in today so I'll check with him.

 

[david339933]

Sec. VIII - Div. 1 - App. 3:
"Completed Pressure Vessel: an assemblage of pressure vessel parts of which no further welding, assembly, or testing is required, and to which a Certification Mark and Designator has been applied and for which a Form U-1 or Form U-1A has been completed".

App. 3:
"Construction: an all-inclusive term comprising material, design, fabrication, examination, inspection, testing, certification and overpressure protection".

NBIC Part III Forward:
"It is the purpose of the National Board Inspection Code to maintain the integrity of pressure-retaining items by providing rules for post-construction activities....."

 

[david339933]

INTERPRETATION 95-05

Subject: Purpose and Scope of the NBIC

1992 Edition with the 1993 Addendum

Question: At what point following the completion of a new power boiler, heating boiler or pressure vessel may the NBIC be used?

Reply: When all requirements of the construction code have been met.

 

[Hurmanetar]

Talked to our AIA and he thought since the vessel hasn't left the shop, a corrected U1A can be submitted instead of an R-stamp, but he will call his boss and check to be sure.

 

[Hurmanetar]

david339933, thank you for the definitions and references. I think it is clear from these definitions that the NBIC "may" be used in both of these cases. But as to whether or not it is "required" to be used and R-stamp "required" to be applied, I still see some gray area. Corrected U1A's are acceptable and I haven't found any limitations on submitting a corrected U1A. Since the vessel has not left the OEM facility, the AI knows that it hasn't been put into service or modified by others. So it is functionally the same as if a weld repair had been made prior to final hydro and inspection by the AI.

It really doesn't matter either way to me whether it gets an R-stamp, but some customers don't like to see an R-stamp on their brand new vessel as it makes them feel like their vessel is somehow less than new.

 

[Hurmanetar]

Our AIA came back and said that in both cases an R-stamp is required.

 

[metengr]

Correct call.

 

[viper3982]

The customer should realize that they changed the scope of the project after the fact.

Either they accept it with an R-stamp, or they accept a cost adder for scope change that is equal to the cost of building them a whole new unit.

(We have had some picky over-seas offshore companies that actually prefer the second option!)