Setting up my gas ?

[GordonC]

Just looking for some advice to see where I am going wrong. I'm trying to set up my co2 with my sealey mig welder. I've fitted a brand new parweld co2 regulator and its wound right out anti clockwise. The problem is when I open the bottle as slow as possible the pressure just runs up straight into the red and the gas leaks out the torch. What am I doing wrong ?

 

[shed or dead]

Hi, there should be no need to open the bottle slowly when the regulator is fitted. The only thing I can think of is that the regulator may have been packaged in 'open' setting to keep calibration or something, though I've never heard of this before. Have you read the instructions?

Could be worth turning it the other way (unless open and closed is clearly marked). Might just be faulty, so wear some eye protection if you're trying it again, just in case.

I hope you get it sorted.

 

[GordonC]

Yeah I tried turning it clockwise but that opens it and the gas comes out faster. I think it must be faulty as I've triple checked it all and its just not right

 

[Bill Edwards]

When you say the pressure runs into the red, what figure is this giving? Is this a contents gauge or a working pressure gauge?
If gas is coming out of your torch it sounds like your torch has a fault - it should shut off the gas flow - but it also sounds like your regulator is faulty, as winding the screw out should stop anything going through it.

 

[Jan]

If the gauge goes right up into the 'red' zone I would immediately suspect that it's the wrong gauge. CO2 is not stored as a pressurized gas, but as a liquid kept in that form by a pressure head on top of it. As such the pressure in the cylinder will stay pretty much constant all the time. It will only dip if you are using a lot as the change in state from liquid to gas absorbs heat and thus cooling the gas component. The problem is obviously with the gas valve in the welder which may have to be replaced. If the welder is new it should be fixed under warranty for free.

Or you could check that the valve isn't being energised by a short circuit somewhere in the current/switching path.

 

[mike 109444]

This is a pic of my CO2 reg. The gauge on the left is bottle pressure and on the right is the regulated flow out (adjusted by the grey knob under the reg) As you can see I have it attached to a CO2 bottle (pub type) When the tap on the bottle is opened fully the bottle gauge then reads only about 3 notches up the gauge (if you imagine at zero it's pointing to 7 o'clock then it only goes up to about 8/9 o'clock and that with a full bottle) I have had it connected to an argon/co2 mix bottle and on that it will go to the 300 bar mark. Are you sure you have JUST CO2 or could it be a Ar/CO2 mix bottle ?
Another possibility is that your reg is duff thus allowing gas at to high a pressure to get to the welders gas valve which may not be rated for such a high pressure and so is not sealing.

 

[GordonC]

Think I've managed to sort it. It was the flow rate gauge that was going straight up to the red so I took it all off had a look at it gave it a shake and put it back on and it seems to work now. Is it right that the contents gauge only goes up a tiny bit above empty when its a full bottle ? I take it thats because its a liquid ?

 

[Jan]

As I said: Virtually all the CO2 'gas' is in a liquid state with just a tiny %age as a gas pressing down on it. As the gaseous gas is bled off the liquid flashes (boils) into gas to replace it. This involves leeching heat from the environment, thus cooling the bottle and the gaseous and liquid states evenly. Do it too fast or for too long and you will see a drop in the gas pressure and maybe even some condensation on the sides of the bottle. In cold weather this could even present as layer of frost. You can see the same effect on LPG bottles for exactly the same reason.