NDT after Heat Treatment

[bupunsu]

Dear All..

Since Heat Treatment (on HAZ) will affect metalurgical of base metals wich (at the end) caused welds imperfections.. So I do believe that NDT (radiographic) shall take place following Heat Treatment (PWHT)..

Could you give me the code/std which align with my thinking (NDT required after PWHT)... ??

FYI.. The pipeline was designed by B31.1 and constructed by API 1104..

I already read those code.. Unfortunately couldn't find it.. I think I miss it somewhere..

 

[metengr]

bupunsu;
The sequence of NDT either before or after PWHT is only identified in B31.3 for base materials P-3, P-4 and P-5A.

In B31.1, NDT can be performed either before or after PWHT to meet code NDT requirements.

 

[bupunsu]

Metengr;
Quote from your thread "..The sequence of NDT either before or after PWHT is only identified in B31.3 for base materials P-3, P-4 and P-5A..." need rectified.
Not only for base materials P-2, P-4 & P-5A..Heat treatment requirement as per table 311.11 (B31.3)..
I wonder that the weld imperfections (as well as crack) will be initiated during PWHT.. Does it possible?? How to verify this possibility..???

 

[metengr]

The higher alloy grades which are air hardenable are more susceptible to delayed or hydrogen cracking, which is the reason for mandating NDT after PWHT.