Torch difference? oxy/ace. and other stuff

[Welderpaul]

Yeah, all the lads are the same, despite most things in the workshop getting loads of wear and abuse - the oxy sets are in good nick because they get looked after, all boc/murex gear, and regularly replaced.

 

[steve202]

I am glad I asked. I knew it was potentially very dangerous. Now make that VERY VERY!

Oxy/Ace course would be a logical next step.

 

[chevykev]

Are cutting nozzles the same for propane as for acetylene ?

 

[Cappy]

Are cutting nozzles the same for propane as for acetylene ?

Nope, the nozzles for acetylene are a one piece copper construction.

While for propane there are two parts, having a copper outer sleeve and a brass inner part.

Both will fit in the same cutting torch though so should you change fuels it is only a matter of changing the regulators and nozzles.

 

[Ian B]

I recently set myself up at home with oxy propane. I've only used it for heating so far (hardening a 3 jaw chuck handle that I made), and I was impressed with how well it worked.

The more I read about acetylene, the happier I am with propane!

I haven't tried cutting with O/P yet - is it much diifferent to O/A? Maybe a bit slower to start, but the same from then on?

Ian

 

[Cappy]

I haven't tried cutting with O/P yet - is it much diifferent to O/A? Maybe a bit slower to start, but the same from then on?

Ian

I think you'll find the lighting technique is slighlty different (I can only go on what I have observed when watching platers in the shipyards)

With Acetylene you can light up and set the flame in mid-air, for want of a better expression. With Propane they always seemed to light the propane then lay the nozzle sideways onto the piece of steel (so that the flame blew along the surface) they were about to cut, before introducing the oxygen. I'm not sure why I think it had something to do with blowing the propane flame out, but I could be wrong.

As you so rightly say, once it's alight it takes marginally longer to preheat the material but as it is the oxygen that does the cutting it's only fractionally slower.

 

[irondarren]

I found when using propane on a cutting nozzle, you have to turn the propane on, get a mid size flame, then introduce oxygen, then increase the propane and then balance with oxygen. if i try a full blown flame and then introduce oxygen it just blows the flame out. With acetylene it doesnt matter you can have as big a flame as you like and then introduce oxy with out the risk of blowing the flame out. I believe it has something to do with the burning speed.

 

[Ian B]

That's about what I found with the heating torch - when you first light the flame, there's a section of unburned gas between the nozzle and the flame. Choking the fuel back a bit coaxes the flame back to the nozzle, allowing oxygen to be introduced.

After this, increase fuel then oxygen.

Ian

 

[kezajones]

*****WRONG, WRONG, WRONG*****


Well not all of it, but a few pointers which might save your life

1) Oxygen cylinders are Black with a White top
2) Acetylene cylinders are maroon (red) and are shorter
3) Oxygen can be drawn off at any appropriate pressure - for example when gas welding a rule of thumb is to use oxygen at the same psi as the nozzle number. Should you be planning to do a lot of gas welding then it might be worth considering getting some proper two stage gauges where the output pressure can be more accurately controlled than witrh the more normal 'cutting gauges'. Also light weight hoses make a great difference.
4) I was always told, on every course I ever went on, Never, ever draw Acetylene off at more than 5 psi - there is a reason which I can't remember right now, but if I find it I will post it.
5) The hoses are more generally coloured red (fuel) and blue(oxygen) not green as in the tex

Finally - ALWAYS have a set of flash back arrestors.

Not quite sure what they mean about "You should not run a tank below 50 psi" - unless they are referring to the contents gauge.

Maybe someone else has a better idea

Later - I have just noticed that the link you have used has .ca at the end which indicates it's from California - as you're in Wales I think you'll find that our UK stuff is a bit different

Hope this helps

that seems to fit in more with what we were told at college a couple weeks ago,

 

[marknotgeorge]

Later - I have just noticed that the link you have used has .ca at the end which indicates it's from California

Actually, .ca means Canada, but I assume they use the same standards as the US.

 

[Cappy]

Actually, .ca means Canada, but I assume they use the same standards as the US.

Thanks for that I knew it wasn't the UK anyway , cheers

 

[weldequip]

It's a popular misconception that Propane is cheaper to use than Acetylene! It may be for you home use lads but you still get a lot of scrap yards etc.using propane instead of acetylene, because 'it's cheaper to refill'. Well it ain't! Acetyelene gives a much faster pre-heat rate & hence much faster cutting speeds (around 3X) & actually works out less expensive than propane.
+ It's actually a 'safer' gas... Have a fire around propane cylinders & it'll take the street with it... Acetylene is contained within the cylinder.
weldequip

 

[irondarren]

Actually Mr Weldequip, its not just the fact that acetylene cuts quicker and requires less time pre heating before cutting. It also requires more oxygen to cut with propane, cut for cut your oxygen consumption will be higher with propane, so you need to factor that into the cost as well, and when you do that it makes propane and expensive cutting fuel

 

[snowcat]

It's a popular misconception that Propane is cheaper to use than Acetylene! It may be for you home use lads but you still get a lot of scrap yards etc.using propane instead of acetylene, because 'it's cheaper to refill'. Well it ain't! Acetyelene gives a much faster pre-heat rate & hence much faster cutting speeds (around 3X) & actually works out less expensive than propane.
+ It's actually a 'safer' gas... Have a fire around propane cylinders & it'll take the street with it... Acetylene is contained within the cylinder.
weldequip

I pay £25 for 47KG of propane, no cylinder rental, hows this more costly??? I also find it neater to cut with as the nozzle can be draged on the work, and rested against the guide, Hmmm safer depends If the fires outside or inside the cylinder, and what about the issues of laying cylinders over when there in the truck, You could argue on the cutting speeds if you were running the pug on 1" plate all day, but surely its normaly the ability of the human on the end of the torch that holds all the keys

 

[Stuggi]

Just sent my granddad's O/A set from 1955 out for a refill/pressure test, and with a little luck they should check out, which means no more tests until 2018 . The cylinders was last refilled in the '80's, so I though it might be a good idea to send them away (they've been sitting in my grandmothers cellar along with a smaller 1966 set for all that time, my granddad used to have an auto repair/fabrication shop). My dad and I thought it best to get a completely new set, regulators, nozzles and everything, and it's quite fun (or disturbing :S) to compare the new set with my granddads old "vintage" set. My new on has flashback arrestors at the regulators, and one-way valves at the gun inlets. Non of this was found on the old set. And the regulators I have looks like if you could use 'em as a hammer and they would work just fine afterwards, while the old ones are made out of thin brass, with only a couple of paper washers to keep 'em from leaking. And my granddad never had any kinds of accidents. Kinda interesting, but since he was a trained shipyard welder and I'm a total noob, it's good to have all that extra protection there.

 

[stick man]

Oxy/Ace Regulators

Hi Everyone,

I am new to to all this, so please bear with me.

I need some help about Oxy and Ace regulators. to fully open the regulator which way do you turn the knob clockwise or anti-clockwise ?


When it is fully open (providing the cylinder valve is open) will the gas be delivered down the hose to the torch or not ?


Thanks.

 

[weldequip]

The regulator is OFF, ie. no gas flow, when the knob is screwed fully out Anti-Clockwise. To get gas flow you screw the knob in Clockwise. Common mistake is screwing it all the way in, thinking you are turning it 'On'...way too much gas pressure for most applications
weldequip

 

[stick man]

Thats great, thanks for that Weldequip.

 

[pedrobedro]

When you turn the regulator knob anti clockwise you will feel it go loose, this is when it loses contact with the diaphragm in the regulator and closes off pressure. Turn the cylinder on then turn the regulator knob clockwise and you will feel the resistance when it is applying pressure.

 

[Zagan]

Hi Everyone,

I am new to to all this, so please bear with me.

I need some help about Oxy and Ace regulators. to fully open the regulator which way do you turn the knob clockwise or anti-clockwise ?


When it is fully open (providing the cylinder valve is open) will the gas be delivered down the hose to the torch or not ?


Thanks.

On the bottle they are left anti-clockwise to open them up.

The reason for that is that everything else is clockwise to open up and if you have a problem of any kind you can close off the bottle real quick.

Also just crack the bottles so half a turn or 1 full hand turn max that is so you can turn off the bottle in the same amount of turn.

That's all for safty.

as a 9kg LPG gas bottle can easily wipe out a whole house plus do damage to the other side of the street. So just imagine what would be left after a 50kg acte bottle going off and if your the guy holding the torch well you an't going to be around after it.

Regulators do exactly that they deliver a set amount of gas down the line.

if your welding you'll require a lower amount of gas.
if your cutting you'll require a much higher amount of gas.

Some regs show the min/max amounts for both welding and cutting.

set them to what you require, I just set them to the max on the regs I have as you can set the real amount of gas needed on the torch.

When you finsh make sure you turn off the torch then bottles (clockwise turns) and then open up the torch and look on the regs to make sure the lines are empty as they could blow if they still have gas in them, same deal as BBQs etc.

Only other thing on here that hasn't been said is that if your going to be cutting.

The cutting heads are for a set size so if your cutting 5mm steel then get a 5mm cutting head if your cutting 30mm steel get a 30mm cutting head, you can get away with it but it really stuffs up the head and doesn't really cut well.

Bit like plasma cutters really