Info needed on triple-torch beveling on Alltra Oxy-Fuel flamecutter

[hatchmar]

Hi, I have done a couple of searches but really have not fond a good place for answers and was wondering if anyone could point me in the right direction-

We are using an Alltra oxy-fuel cutting machine that has been recently fitted with a Triple-torch head for K beveling- none of us has experience with this and we weren't given much/any training. If we had the time, we would just use Trial-and-error but we are extremely busy and anything more than 8-16 hours could really put production behind. Does anyone where I can get any helpful Info on this subject (speeds,feeds,limitations etc..)
I am using pro-nest software and the control is a Burny 10 (the machine is Alltra)
Thanks in advance!

[PlasmaGuru]

A good first step would be to contact Alltra. By all rights they should provide you with adequate training to properly use their equipment.

I can give you some general rules of thumb though.

Typically with a triple torch oxyfuel system where the torch angles are set manually i.e. non-automated style you have to use experience gained from trail and error.

The first task is to set the angles. Always make a test cut to check your torch angles, adjust, and re-test as necessary to achieve your desired bevel and landings.

The maximum thickness you can cut with this style of system is usually in the 3"-4" range depending on tips used. The maximum outer radius you can contour is about 1.5"-2" and minmum hole size around 3"-4" depending on matrial thickness.

Your speeds will be limited by the torch cutting through the most amount of material...i.e. the outer torches. Break out the old trigonomotry! i.e. If you are making a K bevel on 2" thick mild steel with 45 upper and lower bevels the maximum thickness is 2"/sin45 = 2.8" Use the 2.8" to set your cutting speeds. This is a good starting point for straight line bevel cutting.

You also must consider the arc the torches are travelling in when you set cutting speeds. As you start to bevel cut around contours the outer torch is travelling faster than the inner torch and you risk losing the cut on this outer torch. The cutting speeds must be decreased in this situation as to not lose the cut of the outer torch. As you can imagine the tighter the contour the slower you must go to not lose that outer cut which explains where there is a minimum radius contour this system is good for.

Additionally the alloy of the material plays a factor.This is where experience in typical oxyfuel cut speeds for various alloys is beneficial.

I hope this was helpful.

Best of luck!