Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

U stamp vessel with Alteration but no R stamp..

Status
Not open for further replies.

QAIII

Petroleum
Feb 6, 2003
5
0
0
GB
I recieved a 50psi vertical tank, it was U Stamp but the number of nozzles on the U1A is now less than what is installed. Now some of the nozzle have crack on weld and need to be repair. Where I go now for repair? can I satill regain the R stamp.
 
Replies continue below

Recommended for you

U-1A could be a paperwork screw-up. Suggest you contact orginal manufacturer. If these are bad repairs contact your local jurisdiction. This needs to be sorted out before moving forward. Any work will need to be performed by an"R" stamp holder.
 
QAIII-

Another possibility is that you have inherited a vessel which had nozzles added legally with no paperwork. From NBIC '92 Chapter III, Supplement 1, Section C (page 51):
"Repairs of a Routine Nature: Subject to the administrative procedure of the jurisdiction and the approval of the Inspector, the types of repairs listed below... the requirement for the repair report or stamping... may be waived... 8. replacement of nozzles where reinforcement is not a consideration..."

So you could have some additional 3" or smaller nozzles added legally with no paper trail. If your extra nozzles are larger, you have a problem.

jt
 
QAIII,

Is NBIC applicable your area, if so jte is correct. Was this vessel PWHT? nozzles replaced without PWHT could be your culprit for cracked welds. Remember PWHT is also performed pending type of product that the vessel will handle (service conditions). Several factors can lead to cracked welds in a new vessel.. stress, use of inappropriate materials, weld defects not discovered during fabrication, the list goes on. I would be most concerned about the root cause of the cracked nozzles (i.e. fabrication, service requirements or design reasons) before proceeding with any type of repairs. You may find that the cracks are not just limited to the nozzle welds upon further inspection. At this stage the overall quality of the vessel is at question and should not be merely repaired and commissioned without determining the cause of the existing cracked welds.

Good luck

WBH



 
jamesl-

The current edition of the NBIC doesn't come into play.

Historical repairs, for example under the 1992 ed., may have been done without the paperwork ("the requirement for the repair report or stamping... may be waived") in accordance with previous editions.

jt
 
For clarity -
RC-2031 provides for the waiving of the inspectors "Inprocess Involvement". This statement has been a problem since it was first concieved. Numerous inquiries have been made re: the statement. Bottom line...Inprocess involvement is limited to the inspector visit to the site to witness any portion of the repair. It does not relieve the inspector from performing all the administrative attributes of the repair cycle. This includes a complete review of the job package (Welder certs, WPS, Material control, traveler/checklist, calibration data, and signature on the R-1) This was always the case and the intent of the NBIC. The problem was that people interpreted the statement as meaning the Inspectors did not need "any" involvement which was never true.

Lane Baker
Baker Quality Services
LaneBQS@att.net
 
Status
Not open for further replies.
Back
Top