Ok i feel really dumb asking this question but i have never lit a dual fuel before!
I've got everything set up and connected (bar an oxygen leak which needs some PTFE attention!) and now i'm not sure which order to turn the nobs on ;) or off for that matter...
I have a minor by the way ;D
Also am i right in thinking the oxygen nob should be open while the oxycon warms up?
Eeeeeeek the excitement ;D ;D ;D ;D
This is what I do -
turn on oxycon with the knob open at the torch and let it breathe for a few minutes
close gas knob on torch
unscrew regulator knob so that it is fully 'up' and therefore closed
open gas knob fully and then turn back about a quarter turn
open regulator knob to the line (which should be marked on it)
get your lighter or match ready, close oxy knob momentarily, open gas slightly and ignite, open oxy immediately and adjust flame
get melting! :)
Don't use PTFE on an oxygen line!!! Electrical tape is safe though.
If you're setting up for the first time, I still highly recommend Sean's excellent advice here:
Quote from: Hamilton Taylor on February 17, 2011, 10:48:07 AM
5lbs of pressure is 1/3 bar - much less than your hothead!
To set correct pressure for a dual fuel torch on an oxycon:
- set it all up
- with oxycon off, and oxy valve shut, open gas valve on torch
- with lit lighter/candle/other live flame held just under and in front of torch nozzle, open regulator until gas lights.
- adjust regulator until flame is about 6" long
- turn off gas valve at torch
- start oxycon, and open oxy valve at torch
- when oxy line is bled, turn off oxy at torch, light gas
- add oxy and adjust both for neutral flame
Whenever I set up a new system, I follow the list above. It means you have set your gas reg with no drama, and your gas reg should then be set for good, or at least for that gas bottle. No further reg adjustment necessary, just melting glass!
Hope that helped, and I'm not trying to teach egg-sucking...
:)
Sean
don't forget to check for gas leaks, I don't think you can use PTFE tape with oxygen, but that might be just cylinders, not sure, I found loads of good threads which I read before I dared turn on....then you wonder what you were worried about!
you don't need a flame as big as the hot head, I was amazed how little the minor flame was when I saw it at Vonnie's.
Have fun it will be worth it
Pauline
remember PO-OP
ON propane first, then oxygen
OFF, oxygen first, then propane
Isn't is exciting, Gems!
Hope you are up and running now.
Good luck with it and enjoy
Linda x
why can't you use PTFE on oxygen lines ???
My oxycon already had some one the part the christmas tree attaches too...
Quote from: SilverGems89 on December 11, 2011, 05:28:20 PM
why can't you use PTFE on oxygen lines ???
My oxycon already had some one the part the christmas tree attaches too...
I said it shouldn't be used with oxygen Gem - I thought you were going to replace the fitting? It had been put on to make the green nozzle fit but wasn't a permanent solution. I only found out after we had stopped using that OxyCon that there is a risk because of the grease content in the ptfe.
Kazx
Pressurised oxygen does NOT burn by itself (and is why "DUAL FUEL" torches are not actually DUAL FUEL but more accurately should be called DUAL GAS).
However, pressurised oxygen is in some cases extremely dangerous, because although it doesn't burn by itself it will enable other substances to burn extremely fiercely and in some instances it will cause spontaneous combustion. Leaking oxygen can soak into materials - like fabrics and because it makes flammable objects super flammable great care should be taken.
So you must never use any grease, or "organic" based items around oxygen joints, this includes PTFE tape as I believe some types pf PTFE tape are not grease free.
From the BOC website (http://www.boconline.co.uk/products/products_by_type/industrial_gases/oxidant_gases/oxygen.asp)
Oxygen vigorously supports combustion of many materials, which will not normally burn in air
Copper, brass and high quality stainless steel are the most commonly used metals and are compatible with oxygen. However most lubricants are not compatible; oil and grease can ignite spontaneously burning with explosive violence and should not be used with oxygen
Oxygen must never be used with Polytetraflouroethylene (PTFE) tape, as it will cause combustion
Standard PTFE tape contains oil; oxygen reacts violently with oil and may spontaneously burn with an explosive force. BOC does not recommend the use of PTFE or other thread sealing components in conjunction with any gas cylinder valves or regulators
Having said all that - if you are using an oxygen concentrator, the risks are not nearly as great and you don't get quite the same degree of hazard with concentrators as you do with pressurised (or bottles) oxygen. BUT you still shouldn't take any risks so:
DON'T used PTFE tape at all on any of your oxygen lines
and
DON'T use a washing up liquid based leak detector on your oxygen lines as the detergent may contain organic solvent which can cause combustion with oxygen. Get a Proprietory leak based detector fluid which is suitable for oxygen use.
The POOP thing (propane on, oxy on, oxy off, propane off) is to prevent flashbacks where burning gas is flowing thew wrong way back down the hose. Usually this will happen if the oxygen is on and the oxy pressure pushes the propane backwards. The flashback arrestor will stop anything bad happening but if it is a particularly bad flashback it may damage the flashback arrestor. To be honest - the risk of flashbacks on SURFACE MIX torches - such as the Minor Burner or Bobcat etc. is minimal if you turn the gases on in the POOP sequence and very rarely happens with oxycons. Bottled oxygen is a different matter.
In my experience the Minor is a great torch for behaving itself whereas the Bobcat can be a bit if a sod for flashbacks.
The complication arises when you are using an oxycon and you may hear of people running the oxycon before they turn on the propane. The reason for this is:
When the oxycon is turned on it doesn't produce much oxygen to begin with but will pump air around. This air will effectively "blow out" your propane flame and causes havoc when you turn everything on together. If you are familiar with your propane flame leaping up and there being a gap pf several inches between the flame and the torch you're seeing air, not oxygen coming through the oxygen line. After a while this will settle down but often it will blow the propane flame right out. So, a lot of people - me included - will run the oxygen through the torch for around 30 seconds WITH NO PROPANE LIT, until the oxycon has settled down. THEN, you turn OFF the oxygen. The the POOP procedure happens - propane lit and then oxygen added. When you turn off the torch - you turn off the oxygen first and then the propane.
At the end of the session I will let the gases burn off. i.e. I leave the torch burning but turn off the oxycon and then I turn off the propane and just let all the gases exhaust through the torch. Then turn everything off. This is better for the health of your hoses and ensures that you don't have a nasty gas smell hanging around your studio.
Quote from: Kaz on December 11, 2011, 06:53:30 PM
Quote from: SilverGems89 on December 11, 2011, 05:28:20 PM
why can't you use PTFE on oxygen lines ???
My oxycon already had some one the part the christmas tree attaches too...
I said it shouldn't be used with oxygen Gem - I thought you were going to replace the fitting? It had been put on to make the green nozzle fit but wasn't a permanent solution. I only found out after we had stopped using that OxyCon that there is a risk because of the grease content in the ptfe.
Kazx
I'm still trying to source the replacement Kaz but yes the plan is to replace it, I will take the PTFE off and use silicon to glue the christmas tree on instead, i've just found i need a new tree anyway and that is why we couldn't get a seal so have a few days to sort everything out now while i wait for it to arrive ;D
Thanks for that Sal, i think i will have to read that once or twice more over the coming days, my brain seems to be struggling from information overload at the minute!
Uh-uh - silicon is just as bad, if not WORSE than PTFE........ :o You really need to replace the fitting to be on the safe side. Is it worth getting in touch with the manufacturer - Debiliss or whoever they are? They might have a straight swap component?
Gems as Sal says don't use anything on the Oxygen supply. The connectors are designed to seal properly as they are, if the don't then they are either damaged or not tight enough.
My wife has medical Oxygen from a bottle and was warned that a leak can even cause ignition of bedding or soft furnishings without a flame.
Used correctly oxycons are very safe but do take note of the warnings about sealing the pipes.
Looking forward to seeing what you make with your new gear.
Pete
one of the parts needs replacing Pete, hence my seal problem ;)
I have seen on the t'internet that there is oxygen safe teflon tape so i will be off to look for some of that today :)
Have you checked Tuffers, I thought they were stocking replacement christmas trees (green nozzles).
It's the bit the christmas tree attaches to that needs replacing Ruth, although i also needed a new christmas tree (which should be here in the next few days) ;)
Re starting up the Oxycon I have to confess to turing it on with the oxygen valve open on the torch at least 10 - 20 minutes before I want to start torching otherwise as Sal says the oxygen will blow the gas out, I also find that if I don't give the oxycon time to 'wake up' I get a very poor flame for a while. Have fun. :)
Thanks for all your help my lovelies, all new parts fitted and leak checked, and i just made my first beads ;D ;D ;D (OMG is that going to take some getting used to!)
Yay! Fantastic Gems!
Kazx
ollie the oxy is running like a dream Kaz, thank you so much ;D
Oh that's fantastic Gems!!! ;D ;D ;D