i was on a small outage (outside boiler) a few weeks back where engineering finally approved a 5p root for the wall tubes... this results in a lot of effort to flush tubes after welding, and/or shortened turbine life...
tig is great where it works, but not a true do-all process....
johnw, the Lincoln 5P is almost the standard of the industry (6010) Why wouldn't Eng. go to a 5P+ possibly. Was the job that dirty ?