Repair of Section VIII Vessel

[PMarinshaw]

Where can I find the requirements for a specific repair of an ASME U stamped vessel? I have searched API 510 & API 579 without success. I have a 1-1/2" unreinforced nozzle to remove. I want to cut off the nozzle flush with the OD and then weld a patch plate over the hole, rather than attempt direct replacement of the shell area. I'm looking for minimum plate thickness and stress requirements. I remember another document I have used in the past which had requirements (other than the original Section VIII code), but I can’t recall what it was.
Original construction code was 1986 and the alterations & repair would be per latest year/date standards or codes. Vessel specifics: 61” OD, SA-516 Grade 70, P/T is 150 psig @ 550F.

 

[metengr]

API 510 and the NBIC, which would be an applicable in-service repair code, are the only applicable standards or code book for in-service repairs. For your situation you need to install a flush patch plate. A fillet welded scab plate is not permitted. So, use the NBIC, follow the requirements for installing a flush patch and use Section VIII, Div 1 for general welding, PWHT and NDT requirements.