qualification of weld repair after PWHT

[saipemsmspetti]

Is it possible per ASME IX and B 31.3 and B 31.8 to have qualified WPS with PWHT and to avoid qualification for the repair with same essential variables using qualified previous main WPS procedure. The second PWHT will be performed after repair in the same way as qualified by the main WPS.

 

[metengr]

saipemsmspetti;
Could you restate the first part of your question? Your statement about main WPS and qualification of repair are confusing to me.

 

[saipemsmspetti]

metengr;
I have qualified WPS with PWHT. I want to apply this for the repair procedure of the same weld without re-qualification of all this in a row (weld+PWHT+repair+PWHT). Is it possible?

 

[metengr]

Yes. The WPS, if qualified with PWHT, can be used in multiple weld + PWHT repair situations for this weld.

 

[stanweld]

If the material required impact testing per the referenced Code, time at the PWHT temperature is an essential variable. In that event, you may need to requalify your procedure for the extended PWHT time.

 

[saipemsmspetti]

Thank you 'metengr' and 'stanweld'. You both helped me.
It was my humble thought (extended time), but I'll have to take care during proscribing of WPSs and qualification about this extended of time regarding EN 13445-4 (Page 46) and some limit of 3 hours and PWHT temperature to be less than 30 deg. C for Q+T materials. What do you think and suggest about it?

 

[stanweld]

It has been my practice to qualify a WPS for impact tested equipment with the PWHT hold time long enough to permit at least two repairs by welding.