after Root pass need to capping immediately

By TJGOH Date 06-22-2019 01:36

Hi All Pro good days
I am new here, i want to get your opinion, welding on the piping joint, after the root pass, the joint have keep 60 days without capping, then the joint is corroded rusty, can i power blast it and continue capping or need to cut it off and re root again, do your got any reference above this in AWS or others

By Joey

Date 06-24-2019 02:57

What code /std is applicable? An increase in maximum time between root bead and second bead is essential variable in API 1104.

I will not suggest surface cleaning by grit blasting, if needed to continue without cutting it off due to large diameter (e.g. 1meter dia), you may do power brush cleaning to be followed by PT/MT to ensure no surface defect before welding can resume.

By Jim Hughes (***)

Date 06-24-2019 21:51

TJGOH,
It does depend on the COC, and what material is being welded and what the application is. But in the absences of that, the following are my thoughts. Some ASME codes require 30% in the joint before you can leave it, for certain materials. P3,P4,P5A, P5B, P6 and P15E. If it's just P1 to P1 material, I would brush it clean, visually inspect and if you find no visible discontinuities, finish it.