Thread: Oxy-lpg

Norm,
don't know about a LPG to Acetylene adaptor, I have a dedicated LPG gauge. AFAIK you really need different tips if cutting as well, it's pretty difficult to light up the torch otherwise (possible, but a bit spectacular). Can't answer the compressed air question but my gut feeling is that it's probably not possible otherwise it would be used in industry.

Mick

compressed is just that very little oxygen ...the burn part of air....the Oxygen side of the set is just that pure oxy for increasing the burn and therefore the heat of the flame

Pete

You CAN NOT use acetylene equipment with lpg. The regulator is different and the handpiece and cutting nozzle is different too. Have a look at www.cigweld.com.au for some more info.

In regards to the oxygen, fxst is partly right but the high pressure oxygen used in the cutting is fuelling a chemical reaction to erode the steel. If you get the speed right you can turn off the fuel (lpg or acetylene) and the cutting will continue. Don't laugh I have seen this done. So pure oxygen is needed not compressed air.

Don't risk it, especially with high pressure/highly flammable and explosive gas. Spend the money and by the right gear.

YEp, the oxygen in the bottles is not just compressed air, but industrial grade oxygen, as opposed ot medical, which is filtered gooder.

When you cut something with oxy, or LPG/oxy, you aren't burning the steel, but rather oxidising it, albeit at a spectacular rate.

If you don't want to use bottled oxygen with LPG, just get a good 'turbo' burner for the LPG - basically its a venturi pump powered by the LP gas shooting out & sucking in air - no compressor needed.

Have a look for some of the modern blacksmithing sites - ABANA etc - they have details of making your own LPG burners for heating iron, either natural draught or blown with a squirrel fan (not a compressor - not enough volume)

To burn steel is the same as oxidising it. No I did try the air compresser once, it didn't work. You need no adaptor to use an acetylene regulator on a lpg bottle but you can't go the other way around because the presure is to high. You realy need the tips made for lpg or you wont be happy with the setup.

Originally Posted by Wood Butcher

If you get the speed right you can turn off the fuel (lpg or acetylene) and the cutting will continue. Don't laugh I have seen this done.

Hear hear. I have done this with an auto set up to see how far it would go. It got to the end of the plate (about 300mm) and I turned off the acet within an inch of the start of the cut. You'd need a pretty steady hand to keep it going free hand.

Dan

Same principle as an oxy lance
Long piece of steel pipe with oxy connected to one end heat the other end to cherry with sparks just jumping and turn on oxy press against concrete block and as the pipe oxidises away burns through the concrete to cut a perfect hole through the concrete as you push the lance into it
Saw it demonstrated once , but never found a possible reason to use it.


Rgds

You will need a dedicated lpg regulator and different hoses (orange and blue)
I have been told that using lpg in regular maroon and black oxy/acet hoses will damage them. The hand piece and mixer are the same but different tips are also needed. The cutting tips are two piece and the brazing tips are almost the same but have a recess at the tip to help keep the flame lit.
When lighting them allow a tiny bit of oxygen to flow to allow easy starting.
Elgas also have a product called razor gas which is supposed to be a different mix to lpg and thus burns a bit hotter but you still wont be able to fusion weld mild steel with it.
Be carefull with LPG its heavier than air and will sink into the lowest area if you have a leak in your rig.

G'day & welcome Fly,
We all would like to hear more from you. It may not happen if you go the el cheapo route with gas brazing and heating applications.

Please do take the very good advice given here.You may have misunderstood what was out there on the net.

check this site out re LP gas gas Equipment

http://www.cigweld.com.au/uplFiles/p...0June%2005.pdf
specifically part no 308134

Cigweld is a long standing Aussie company of excellent reputation locally manufacturing gas welding and cutting equipment to Australian Safety standards.

Other companies import similiar looking equipment with no compliance at all to our local standards. I have a friend who is a liscensed and accreditted repairer of gas welding cutting gear. He will not repair some of the overseas made equipment.To do so would make him liable in case of an accident.
It is possible to cut steel using LP gas a a heating source. I did so for a good while as an apprentice boilermaker. You do need to use an oxygen cylinder as it is nearly 100% pure .I can't remember the % of oxygen in normal air but it is not enough.

cheers
Grahame

Grahame,
close enough to 80:20, nitrogen: oxygen

Mick

Originally Posted by Ashore

Same principle as an oxy lance
Long piece of steel pipe with oxy connected to one end heat the other end to cherry with sparks just jumping and turn on oxy press against concrete block and as the pipe oxidises away burns through the concrete to cut a perfect hole through the concrete as you push the lance into it
Saw it demonstrated once , but never found a possible reason to use it.


Rgds

We use oxy lancing regulary... there's not much it wont cut through... even cast water jackets in our blast furnace(bang pop bang pop, change the undies).
We use 2 types of rod, the blastfurnace(makes lead from sinter/ore's) uses approx 20mm dia mild steel rod with some sort of filler rods inside it, and over the silver yard in the BBOC(silver/lead separating furnace)they use hollow S/S 10mm rod.
The main use is to open tapping spout's, and then too burn holes in bridges that form inside a furnace blocking the flow of molten metal through it.

Oxygen is supplied by man18's... yer dont wana see one of these on fire... I have watched the Firey's hosing these down to keep them cool in the middle of a flowing molten metal spill, scary stuff!:eek: