PWHT of P5A MAT'L

[JIPMKWA]

ASME Sec. 1 is a code for construction , not repair but under table PW-39.1 defining nominal thicknesses it mentions material repair under (C)

For the scenario that I am in now - On the secondary superheater outlet header ( SA 335 P22) socket welds ( SA 213 T22 tube stubs). We are chasing indications , clearing them with Wet MT and then re-welding them with a temper bead.

I am reading the PWHT requirements from table PW-39-4 (A) (1) (3) and it says a nominal base metal thickness of 5/8" or more requires PWHT. Going back to my original comment from table PW-39.1 (C) , it defines nominal base metal thickness as the depth of the weld for PJP's or fillet welds on material repair

Am I interpreting this correctly that regardless of base metal thickness when repairing a wash zone on a header / or crack in a socket weld. That as long as we do not go deeper than a 5/8" excavation and we pre-heat correctly - No PWHT is required nor a temper bead ?

 

[metengr]

First, you should be using the NBIC for weld repair guidance versus Section I. By using Section I for weld repair of in-service components, temper bead repairs would not even be permitted for material other than carbon steel in PW-40.

Guidance in Section I should be used for determination of PWHT for in-service components. In your case, the nominal base metal thickness is 5/8" depth. This means 5/8" base metal thickness and not nominal thickness as defined by repair depth elsewhere in the Code.

So, using the NBIC, Part 3 you are into Alternative Welding Method 4 for P-No 5A material. You should not be using Section I for in-service weld repairs other than to determine the need for PWHT and temperature and time requirements. Weld repair requirements for Section I in PW-39 and PW-40, pertain to defect repairs during fabrication, and not in-service repairs.

 

[JIPMKWA]

Thanks metengr ! The word "repair" was throwing me off.