Originally Posted by oldred
These "one size fits all" suggestions for Oxy/fuel settings is simply ridiculous and the Oxygen pressure needs to be set for the task at hand, are you saying you cut 1/4" plate with 40 PSI Oxygen? How about 1/8" plate? What about 6" plate even with a large tip? Sure 40 PSI CAN work in a lot of situations but there are a heck of a lot more where a lot less pressure, or more pressure, would work a lot better. Using 40 PSI on thin plate is going to waste a lot of Oxygen and with the right (small tip) it is going to make a poor cut! Fellas there IS NOT ANY ONE SETTING FOR OXYGEN! Even Acetylene sometimes needs more than 7 PSI although for the vast majority of jobs that setting would be fine, try using a no. 6 (Victor) tip to cut 6" plate with only 7 PSI on the fuel gauge, might work if you have 1/2" hose! Learn to set the Oxygen pressure to whatever works properly for what is being done and I would think that for what most of the guys here would be using a torch for 40 PSI Oxygen is simply way too high, even if it works ok you would be wasting a lot of it on thin plate.
I've never had a problem cutting plate up to or more than 6" with OXY set at 40 PSI and Acetylene at 7 PSI,i just do a bit of preheating with the torch before i make the cut and they've come out clean cuts..which personaly i do the little pre-heat on anything or any size i cut with a OXY/Acetylene torch,it makes a cleaner cut.
The summer of 2008 up in Morgantown W.V. i was on the new coal burner they were building,biggest boilers in the USA,i was regularly the one cutting the cope out on the beams because the steel was fabbed in china and nothing fit right,and the beams were anything from 1/2" to 8",using a #3 tip on the thicker iron.
The only time i've ever had to set it higher is if we added a hundred feet or more to the hose to get up high somewhere or somewhere where the torch cart couldn't go.
I've never seen it a problem as waisting OXY at 40 PSI with anything 1/4" up,anything thinner i use a Plasma Arc or a 6" Metabo or Dewault with a cutting wheel.
Use the right size tip according to the size steel you're cutting and the tip won't let it waiste OXY with it set at 40 PSI
I do agree that anyone using an OXY/Acetylene torch to cut 1/8" or less will get away with less pressure settings,but i'd never use it for that for the fact it will warp anything that small or smaller even with a .00 tip making it a mess to straighten out.