Welding old plate / pipe with new

[Dhurjati Sen]

Dear experts,

When you have to weld old pipe / plate with new, what WPS (and corresponding PQR) one should follow?

And why?

As an example let us take welding of old SS 304 plate, 2 mm thick with new.

Best regards.



DHURJATI SEN
Kolkata, India

 

[kingnero]

If you have the MTR of the old material and/or can positively identify the grade, the age does not matter.
If really old material or there is doubt about the base material, treat it as a one off and separately qualify that material to "new" 304.

 

[mk3223]

The WPS is the same regardless the parts of the same "group" of material are new or old.
To ensure the parts to be "clean" prior to welding.