Oxycon

[trialuser]

Hello everyone - happy Christmas and all that stuff.
I've just got a 'refurbished' oxycon from the well known glass making supplier and am very pleased so far, brilliant speedy service. (ordered yesterday, arrived this morning:-) )
I have a question which I hope other users will be able to help me with.
I am using it with a smiths little torch (probably a counterfit) and a number 6 nozzle.
The flow rate needs to be set so low that the flow ball doesn't even move and after a few minutes the red service light comes on. If I up the flow rate, which obviously blows the flame out, the red light goes off.
I have contacted the supplier and they too think it's because the flow is so low.
Do any of you use this combination, and do you get the red light on?
Does anyone know the mechanics of these and if, effectively strangulating the machine to virtually no flow, will damage it.
Thanks
Martyn

[medusa]

I don't get the res service light come on on mine, but the amount of oxygen which comes through needs to be minuscule as it blows the flame out otherwise. I think I need something bigger than a number 6.

[mizgeorge]

I set my oxycon at about 2lpm, and that seems spot on for the little torch. You need to control the flow to torch at the torch end - light with propane only and then 'dial in' the oxygen with the torch valve.

[medusa]

I set my oxycon at about 2lpm, and that seems spot on for the little torch. You need to control the flow to torch at the torch end - light with propane only and then 'dial in' the oxygen with the torch valve.

I do that, but it still seems to keep blowing out. I know I'm going wrong somewhere, just not quite sure where!

[trialuser]

Thanks for the replies.
I know how to light it, it can be lit whether the flow rate is set to 1 or 5 lpm, as you say, the output to the torch is determined by the oxygen knob on the torch.
I just wondered if it was usual to get the red service light come on.
When I was on bottled O2, I only used 1 lpm, but I suppose that is 100% and the oxycon would be low 90's at best I suppose.
Cheers
Martyn
here is a video https://www.dropbox.com/s/gexg7j3p8w0xh46/oxycon.mov

[medusa]

I set my oxycon at about 2lpm, and that seems spot on for the little torch. You need to control the flow to torch at the torch end - light with propane only and then 'dial in' the oxygen with the torch valve.

I do that, but it still seems to keep blowing out. I know I'm going wrong somewhere, just not quite sure where!

[trialuser]

The flow meter on the oxycon is just indicating the flow rate (in lpm) through the flowmeter.
Assuming there are no leaks in the hose, this is determined by the flow rate through the torch, it can't be anything else, the oxygen is only going out through the torch, unless the torch is huge and can use more O2 than the oxycon can deliver, also ignoring the pipe resistance which can be ignore in this case.
If you put your finger over the end of the nozzle and stop the flow - the flow rate drops to nothing, unsurprisingly :-) The ball float is not indicating pressure.
Medusa - perhaps try a gentler touch - gently on the knob. I'm sure someone will chirp in here!

[mizgeorge]

Just a thought trialuser, but are you letting it run (valves open) for a while before you use it?

Liz - take a look here: http://www.frit-happens.co.uk/forum/...?topic=38577.0 (amongst other oxycon threads on that forum). It sounds almost like you're getting some air rather than oxygen, which could mean an internal leak. There are some threads on FHF about how to deal with that too.

[medusa]

I'll have a ponder, George. I can get a blue flame, but it's so tiny it is really difficult to get even quite small things hot. If I try to make it bigger, it just goes out. I thought it was just that the number 6 nozzle is too small and I need a bigger one, but now I'm concerned it's something more serious.

[trialuser]

Medusa - the video I linked to above is using a no 6 nozzle - is yours like that, it has plenty of heat for rings and the like.
George - I wasn't aware I was supposed to run it open circuit to start, but yes, coincidentally I have done this on some of the occasions.
I work as a Paramedic so I come across these fairly often with people on home Oxygen. I have seen them set as low as 1 lpm so I would have thought they would be ok at low flow rates without triggering a red light.