Oxy vs acetylene on a big plate job last month

I was working on this pressure vessel repair down in Houston and had to decide between oxy fuel and acetylene for preheating a 2 inch thick plate. My foreman swore by oxy because it's cheaper, but I went with acetylene cause it heats up way faster and I was on a tight deadline. The acetylene torch got that plate to 300 degrees in about 8 minutes, which saved me almost 20 minutes per weld pass. Ended up finishing the job a full day early and the X ray results came back clean. The extra cost on the gas was maybe $60 but the time savings was worth every penny. Has anyone else run into this debate on heavy wall stuff?

2 comments

2 Comments

ivan4021d ago

Hold up a second on that 2 inch thick plate needing 300 degrees. For most pressure vessel codes, especially if you're talking Houston refinery work, preheat on 2 inch thick carbon steel is usually more like 200 to 250 degrees, not 300. Going to 300 is fine and won't hurt anything, but you might be burning extra gas for no real reason. I had a similar job last year on a 3 inch thick shell, and my CWI told me to stick right at 200 minimum per the WPS, and we passed X ray just fine. Just a heads up so you're not wasting acetylene next time.

leo56720d ago

Same here, 225 degrees worked fine on a 2 inch job last month.