Propane Tank For A Propane Cutting Torch

A friend asked me what he needed to covert from a acetylene to Lp gas cutting torch. I know he needs a type T hose for the torch and a LP cutting tip. He may need an adapter for the regulator to from acetylene to a Propane tank. I use a 40lb LP tank on mine that does not have the safety over-fill on it. My LP supplier says that if it had the safety valve on it, that the valve would not let enough vapor out to the torch. He told me that he was supposed to put a red tag on the tank saying it is for a cutting torch. So far he never put a tag on it. The friend asked me if he could just use a LP tank from his grille (20 LB ), I told him I didn't know. The welding outfit that I bought my torch from recommended the 40 lb tank. I had mine since 1993 and never had any problems.

I use the same set up for propane as I use with acetylene only I change the tip to the two piece for propane no regulator changes no hose changes no nuthin been using both types for years

If you have a 20 lb tank with the old style valve it will work for a torch. A hundred lb tank will work too. If the 20 lb tanks are not tagged the suppliers are not supposed to fill them. Some do.

I'm the same as terry I just use a 5 gal tank last along time change tip screw reg into tank cut away

All that is needed is the two piece propane tip , regulator and hose are the same I've used mine like that for forty years

I totally agree with what the others have said. You do not need any special hose or regulator adaptor. I use a 100lb tank and have for a long time now. They make different# tips for propane just like they do for Oxyacetylene tips. The only difference I have noted it the propane is not as hot as acetylene. Just my thoughts, Keith

So are these opinions coming from, "I've been doing it for years and nothing bad has happened yet," or from actual knowledge?

My understanding is similar to the OP, that acetylene hose and propane/MAPP hose are different, and using the wrong gas causes the hose to degrade and eventually leak/burst.

My thoughts exactly , at work in a manufacturing plant we switched to propane 10 yrs ago and I'm pretty sure just changed the nozzles on I am sure over 100 torches, OSHA practically lives there too so I'm pretty sure its safe, not as hot but you hold the end further from what you are cutting,

30 pound tank from a camper is correct fitting. I have not found a hose labled for LP. I bought tips and tried but had big problems getting it to light. went back to acetleene after shortage was over.

One eventually needs to up date the hoses and the propane regulator since propane will eventually eat out the acet. hoses. Yet as is stated just change tank and tips for cutting. One can modify the brazzing type tip or purchase the modified ones. I like the oxo propane works good for all I do heating bending cutting. I will eventually up date all my old hose and regs but for now mine is second hand and for the little I do it serves its purpose now with just the cutting tip only.

Had a friend who used propane for cutting. He told me to turn up the oxygen more for cutting. It will use more oxygen with propane.

That's all we've used for 50 years. I don't know what size the tank is,but it's one of the big ones like would site outside a house for a gas stove. The only thing we use any different as far as equipment is the tip.

It takes a different lighting procedure. When I light the torch, I turn the torch gas valve on just a little bit and aim the tip towards a shielded area and then strike a spark. It lights easily with a small flame still hugging the tip. Then add a small amount of O2, keeping the flame at the tip. Increase the LP and then increase the O2. If the flame walks away from the tip, just reduce the O2 a bit until it comes back to the tip. You never get the dark smoke that burning Acetylene produces during lighting. LP gives a cleaner burn.

I have used LP and O2 for more than 50 years and about 2 years ago needed to replace my hoses for the 1st time. My Smith regulators are still original. For working with steel up to 1/2" thick (bending or cutting) I get enough LP coming off a 20# BBQ tank even with the newer valve. I do have bigger LP tanks available, but have found their bigger size and weight to be an inconvenience. I also have a LP blacksmith forge requiring only LP and no Oxygen. It is naturally aspirated, single burner. The local farriers use 2 burner forges with BBQ tanks for supply.

I will agree that there are some metal working processes that are better done with acetylene +O2. But for the few times that I have needed or wanted Ac, it is not worth the price for tank purchase or rental plus the cost of the gas. LP is a bit different, but far less costly.

Paul in MN

I use a 10LB lp bottle because a 20Lb grill bottle is too large in diameter to fit a standard size welding cart. I can't imagine why anybody would haul a 100 tank around unless they were using a rose bud for hours at a time. My 10 pounder easily last's longer than the 125 cu ft oxygen tank. You should use type T hose and even the opd tanks have pol fitting same as old style tanks.

My Friend is happy with the responses. He is on his way to get the things he needs.

T hose is required, and it has been the standard hose for about 40 years now. I have run a 20# lp running thorough a OPD valve with no trouble at all. The only reason to mark a tank For Welding Only, is a tank less than 33# needs a OPD Valve unless it is a commercial use(cutting)

I hope he is getting hoses made for LP gas because they are different from acetylene gas. Hopefully the guys who are selling what he needs will know what they are selling.

I already had the 30# tanks for my camper and I bought my tanks back in I think it was 79. I have been told to turn oxygen on a bit before turning on LP and other ways and just could not get things to work. In the bright sun I could see the acetlene flame to adjust after getting lit, the LP if I managed to get lit I could not see the flame to tell if I was getting it adjusted or not. Some years I might go thru 2 tanks and other years not even a full tank so I don't use enough that cost was enough to compensate for the problems I was having.

Leroy,

You are right, when lighting the flame is hard to see in sunlight. So I have a "box" about 5" square open on both ends (scrap steel) that I use to light the torch. The box is dark inside so I can see the flame easily and it shields the gas coming from the torch tip so the gas doesn't just blow away. I do most of my torch work outside so as to not create a fire risk in the barn/shop. One BBQ tank lasts me 2 to 3 years.

To each their own. I'm not trying to sell anyone on the use of LP, but I have found it to be a successful solution in my shop and shops of both of my sons. None of the 3 of us is into welding with Acetylene, just heating, cutting, and bending. I have been able to braze sheet metal items like oil pans with the LP/Oxy.

Paul in MN

I only use the torch for cutting and heating. That box is something to remember if I try the LP again.

It is when you are trying for 5 minuts to get torch lit and still not getting it done for that 30 second job and turn torch off you get disgusted and give up and go back to something you can get lit and get that 30 second job done.