Visited a job site in Gary and saw everyone skipping the pre-heat on thick plate

I watched three guys weld a 1.5 inch flange at a refinery in Gary last Tuesday without any pre-heat and they all swore it was fine, but my old foreman would have sent us home for that, so who here actually follows the pre-heat tables on the regular?

2 comments

2 Comments

felix_bailey451mo ago

My old foreman would have grabbed the preheat torch himself and lit it under their lunchboxes just to make a point. I saw a guy try to weld a 1 inch flange cold once and the crack sounded like a firecracker going off before he even finished the bead. Those boys in Gary are playing with fire and calling it fine until that weld lets go in the middle of a pressure test. The tables are there because someone already learned that lesson with a trip to the hospital.

torres.drew1mo ago

And @felix_bailey45 is right on the money about those tables being written in blood pretty much. I've seen it happen too, a cold weld on a thick flange that looked fine for a week then let go like a shotgun blast during hydrotest. These guys in Gary probably think they're saving time but they're just gambling on the job holding long enough for them to get paid and leave. The thing about hydrogen cracking is it doesn't show up right away, it waits a day or two then pops when nobody expects it. I bet if you checked those welds with a UT scan in a week you'd find micro cracks all along the HAZ.