"R" Stamp required or not?
"R" Stamp required or not?
(OP)
We recently recieved a pressure vessel and installed it in our system. Before actually putting it into service we discovered a pinhole leak on one of the weld seams on the shell during a Nitrogen purge/leak test of other devices. We sent the vessel back for repair, and it arrived back without an "R" Stamp or other documentation. Is this legal given that the vessel never was commished into service in our system, or does it require an "R" stamp because it was initially inspected, hydrotested, and "U" stamped regardless of the fact it never officially went into service?





RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
Patricia Lougheed
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RE: "R" Stamp required or not?
Once a pressure vessel is completed, (stamped, hydrotested and witnessed b y the AI) it is no longer under the scope of code of construction, period. The vessel can sit idle for years and not be commissioned.
RE: "R" Stamp required or not?
Thanks, that was my understanding as well. Because this is the first time we have had this issue, I just wanted to make sure my understanding of the code was correct before contacting the fabricator tomorrow.
RE: "R" Stamp required or not?
If this is indeed a nonconformance I would suggest you have the repair organization supply you with a qualified welding procedure specification and perform surface and radiographic examination to ensure suitable weld repair. You are going to need to assemble as much information regarding how the weld repair was performed and post weld repair NDT for acceptance of this nonconformance.
Your other other option is to hire an organization with a current R-Certificate and have them re-repair this location.
RE: "R" Stamp required or not?
I'm only trying to make sure they aren't taking advantage of us since I'm not an ASME expert. Having the above new information does this sound reasonable or they just trying pull the wool over our eyes. This is a small CS horizontal vessel (24" Dia x 48 overall length) with 150 psi design pressure, and basically ambient temp.
Thanks in advance!
RE: "R" Stamp required or not?
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Incorrect assumption and no understanding of code rules. They need to review Part 3 of the NBIC under Weld Repair. Minor or major repair, when an arc is struck you need an R-Certificate, period.
As I mentioned this vessel is no longer under fabrication because it is COMPLETED. The fabricator is unaware of ASME code rules. Go back and cite to them UG-99 a) 1 of ASME Section VIII, Div 1.
RE: "R" Stamp required or not?
If I remember correctly, someone in the forum many years ago saying if the original WPS/PQR is applied, no need for R-stamp to repair a crack seam or nozzle. Is that a true statement ?(we do apply R-stamp for repair)
RE: "R" Stamp required or not?
No, this is incorrect.
RE: "R" Stamp required or not?
If the exact same thing had happened but the vessel had never left the shop I can guarantee that no "R" stamp would be applied.
-Christine
RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
My construction manager says " Oh no, you don't need to".
RE: "R" Stamp required or not?
People are mixing apples and oranges. IF an ASME code stamped is completed - stamped, hydrotested and signed data report the vessel is COMPLETED by ASME Code.
Any welding after this point if in the shop, on a barge, in the field etc., must be done by a qualified organization with an R-Stamp if done to the NBIC) or other in-service code.
RE: "R" Stamp required or not?
I was the fabrication manager for a company that fabricated both code stamped and unstamped vessels. Only the code stamped vessels were required to be repaired in accordance with the NBIC. Those vessels with a code stamped nameplate that were damaged, after the AI witnessed the hydrotest and all documentation was completed, during loading, shipping, unloading, etc. were required to be repaired under the auspices of our "R" stamp.
Vessels sold to clients that did not require the vessel to have an ASME stamped nameplate, even though they were designed and fabricated per ASME, did not require final inspection by the AI nor did the AI witness the hydrotest. Repairs to those vessels that were not require an “R” stamp.
Best regards - Al
RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
I have a real case. A code stamped vessel fabricated many years ago, never put to service. Another company bought this vessel and shipped to overseas, and got damage in shipping. They hired a third party U/R stamp qualified vendor to fix the damage, for sure it involved welding and NDE. Is the "R" stamp required to be added to the original U stamp ?
What you say " ...were required to be repaired under the auspices of our "R" stamp" may not always happen, especially when it is shipped to overseas. We also have the original vendor went bankruptcy.
However I understand your point is the "warranty" issue. Let's put that aside for now.
RE: "R" Stamp required or not?
In the original post I mentioned it was "U" stamped. It was manufactured in California and could literally be in sevice anywhere in the world so it is also PED certified. It's final destination is determined when assembled into the system after an order is placed.
Anyway this subject is still open and unresolved between the manufacturer and us. Hopefully a resolution will take palce in the next week. I'll post the final outcome. In the mean time any other info is appreciated.
RE: "R" Stamp required or not?
If the Repair contractor's AI deems that the repair is inconsequential enough, and 'calls' it a Repair-of-a-Routine-Nature, only the R-1 form is completed. No R-stamp data plate required.
Some of the above folks are over-interpreting API-510 and NBIC on the subject of hydro. If the repair area is truly a pinhole, the only way the contractor's AI will require a full hydro is if he is VERY unsure of himself, is mad at the contractor, or mad at you. The purpose of a hydro is to proof-test the design and fabrication of a vessel, to make damn sure that the vessel will not go BOOM in service. Minor repairs do not change the pressure capacity of a vessel. Remember, we are allowed to add a 2"NPS nozzle without calculations or reinforcement, meaning that 2"NPS-sized holes will not hurt the pressure capacity of a vessel.
RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
The NDT method performed to determine 'crack' vs. 'pinhole' will usually be deemed as adequate evidence of a successful repair. It is VERY imprudent to re-perform the original hydro on a used vessel.
RE: "R" Stamp required or not?
Without re-hydrotest, end user must be willing to take the risk of failure during operation.
Practically from what I have seen, re-hydrotest is hardly done to save cost and to improve schedule. A day's down time is equal to million $$ for a plant.
If any of you are just an engineer like me, not an AI or end user, do not make any decision not to re-hydrotest. Read the NBIC, present the fact to AI and end user, let them make the call.
RE: "R" Stamp required or not?
RE: "R" Stamp required or not?
The Code does not permit one to simply go back and repair/alter a completed vessel and simply re-hydrotest the vessel and now say it is what, RE_COMPLETED?