pressure setting on cutting torches?

[justin_rathjen]

hey guys, just got a new acyt. and oxy cutting torch, I do know how to use it but was just wondering if there was a recommended pressure to set both guages at, and if it makes a diff? might as well use it right, huh? I have to work all weekend laying brick so i might not be able to say thanks for the help, so i'll say thanks in advance.

 

[krusty the clown]

i usually run 40psi on ox and 7psi on ac.

 

[justin_rathjen]

why is that?

 

[35mastr]

I normally run 5 on acetylene and 10 to 30 on the oxy.

 

[krusty the clown]

why is that?

thats what i was taught.


IIRC the ranges for pressure are 5-8 for acet and 25-40 for ox. if your cutting thin stuff use lower pressures, thick stuff higher pressures. you'll have to experiment to find out what your torch works best at depending on what your cutting.

 

[35mastr]

thats what i was taught.


IIRC the ranges for pressure are 5-8 for acet and 25-40 for ox. if your cutting thin stuff use lower pressures, thick stuff higher pressures. you'll have to experiment to find out what your torch works best at depending on what your cutting.

This is very correct. If you are just using them for brazing and soldering. 5 on ac and 10 on oxy will be plenty.

Remember that the higher the pressure you use will consume the bottles quicker.

 

[nate379]

I usually run around 10psi on acetylene and 20-25 on oxygen for heating and for cutting I'll kick the oxy up a little more to maybe 30-35.

 

[lilclay81]

i use 5 on acetylene and 20 on oxygen works really good on just about anything

 

[A_Pmech]

Justin,

Here's a Victor chart that will give you a start. You should locate a manual from your torch manufacturer. It will have a similar table:

 

[Underdog]

I usually run 30 to 40 psi on the oxygen and around 10 psi on the acetylene. Does it really matter what the acetylene is set at since you really regulate it by the torch valve as opposed to the oxygen that is wide open when you depress the cutting lever?

 

[wreckercologist]

I usually run 30 to 40 psi on the oxygen and around 10 psi on the acetylene. Does it really matter what the acetylene is set at since you really regulate it by the torch valve as opposed to the oxygen that is wide open when you depress the cutting lever?

Yes, it matters. If you look at the chart A_P posted, with the proper tip and hose size, you can cut 12 inches of steel at 10 PSI. The chart also states to not run acetylene over 15 PSI AND if you need additional volume to use a manifold and run multiple bottles. This is because acetylene cannot exist by it's self in nature. It has to have a binding agent which is a solid. If you turn to PSI up too high and draw too much volume, the binding agent will be drawn into the regulator possibly causing an explosion.

So, if you set the regulator properly, then you don't have to worry about when the knob on the torch gets bumped.

I don't remember what size the tips are at work, but I set the regs at 4 PSI for acetylene and 30ish PSI on the oxy. Again, this all depends on the hoses and tips and the work you're cutting but I can saw through a 1" plate if the tip is clean.

It's all about safety and using the least amount of gas possible.

My dad use to start a cut and then turn off the acetylene and finish the cut with oxygen only.

 

[justin_rathjen]

thanks guys, well off to work, late already thanks to TGJ! My wife said "why don't you just look it up on google"? I'm thinkin, what the hell do you think TGJ is for?

 

[Vernmotor]

7 & 21 here ,Just what I was taught...?? been doing it that way for 25 years

 

[notme_76]

it all depends on tip size, minimum on acetylene is 5psi because less then that it can flow back into the bottle...some atmospheric thing...i usually run around 7 on the acy and change the oxy from 30-40 depending on size of tip...and as far as that chart saying you can cut thru 12" with 55psi....good luck!!!! ive actually cut thru 12" on a manifold system no regulator wide open pressure...100psi + and it was still a fight!

 

[nate379]

It doesn't really matter to a degree. The gauge settings are a rough adjustment and the knobs on the torch a fine adjustment.

Granted it's pointless to run the gauges near wide open if you are barely cracking open the valves on the torch handle.

All the torches I have used have 3 knobs, 2 for your normal oxy/acy mix and the 3rd is for the cutting oxy.

Good safety practice is to not have those knobs open wide open so if SHTF you can turn it off quickly. Also same applies to the acy tank valve. oxy gets opened wide open, acy 1 full turn and that's it.


I don't agree with that book, but I guess I don't use my torch set "by the book". Was taught by my Dad who was taught by his Dad... (you get the idea). Has been working fine for me for ~15 years, so I'll stick with it.

I usually run 30 to 40 psi on the oxygen and around 10 psi on the acetylene. Does it really matter what the acetylene is set at since you really regulate it by the torch valve as opposed to the oxygen that is wide open when you depress the cutting lever?

The binder for acetylene is acetone BTW. The drawing it out thing is also the reason you can't use an acy tank on it's side and if it has been on it's side, you need to give it some time after up righting it as well.

 

[D KRAGER]

6 - 40 is where mine is usually at.

 

[e-tek]

Thanks for that Chart A_P!

 

[1stwarrior95]

You usually get less slag with lower acetylene psi too.