Heat treatment inservices pressure vessel is Repair or Alteration

[chonburi]

Dear all member,

Bachgound

U-stamp vessel without require heat treatment by original construction Code(SC-VIII-1) and User design spec. After vessel inservice for period of time(unknown for now), User require R-Stamp certificate holder to perform "Heat treatment with whole vessel".

Question 1: With this requirement by user, this activity should be consider Repair or Alteration accordance to NBIC-NB23;

Question2: R-Stamp certificate holder should do any design calculation, NDE(before/after heat treat),Hydro test e.t.c.

Thanks inadvance for all comment sir.

 

[metengr]

chonburi;
If only a heat treatment was performed of the entire vessel unrelated to weld repairs, this is not a repair or alteration.

The NBIC or NB-23 publication only involves welded repairs and for alterations these can be welded (with work) or no physical work - rerating original design conditions.

You do not mention enough information in your background other than a heat treatment was performed on an entire vessel after being in service.

As long as the vessel mechanical properties have not been changed or altered from heat treatment, there is no involvement with the NBIC.