Changed my mind about pre-heating large diameter pipe for fit-up

I was working on a boiler replacement in Cincinnati last month, and the lead hand told me to skip the pre-heat on a 24-inch carbon steel run we were fitting. I argued, said the code book says to pre-heat anything over 1 inch thick to avoid cracking. He pulled out his phone and showed me a chart from the Lincoln Electric app. It said for the specific low-hydrogen rod we were using, and with the ambient temp above 50 degrees, you could go up to 1.5 inches without pre-heat if you kept the interpass temp controlled. I had no idea the electrode type changed the rule that much. We did it his way, kept a close eye on the temps with a temp stick, and the x-rays came back clean. I've been over-prepping for years. Anyone else run into specific weld procedure details that totally flipped a standard practice for you?

3 comments

3 Comments

james_bell3d ago

Wait, he just pulled out his phone and showed you a chart? That's wild, I always thought those code book rules were set in stone. It's crazy how much the specific rod changes the whole game, makes you wonder what else we're all doing the hard way for no reason. I'd be double checking every old habit after that.

aaron7403d ago

Honestly it feels overblown. Most of the code rules are there for safety, not to make work harder. A chart on a phone doesn't mean the old way was wrong, just maybe not the only way. Guys have been bending conduit fine for decades without an app. Sometimes new tools just complicate simple tasks.

cole5493d ago

You're not wrong about the old ways working. But man, I still have a few scrap pieces of conduit from my apprentice days that look like modern art. My old foreman called my three-point saddle bends "abstract expressionism." The phone chart would have saved me a lot of metal and a little pride.