Flowmeter gauges V Pressure gauges?

[Sunny01]

Hi Everybody!

I am a newbie here and yes I do need your help please.

I had for many years a 130 SIP migmate with a disposable small gas bottle strapped at its back. Never used it in ±40 years. Now that I’ve moved to Bulgaria and retired ,decided to have a go and start doing some window security bits around the house, (thin stuff 3mm).

Now the problem started when I got from my neighbour an almost full CO2 Pub gas bottle with gauges reading MPa. The inlet gauge goes up to 25MPa and the working one up to 1.6MPa.

From what I can make out, these gauges are for regulating pressure Mega-pascal and not flow, right?
How can I use them to do a bit of mig welding? What pressure, and not flow, should I set the working gauge at? How can I play with it? Does anybody have an idea?

I bought some Chinese flow-rate gauges, but they do not fit my pub bottle . (The union, bottle/gauges is different).

And the new ones that I bought from China they look and feel so light and flimsy with their plastic tubes with their ball bearing floats, that I am worried they will blow a hole in my ceiling, or me, if anything goes wrong.

So please guys does anyone has any helpful ideas to my problem?
Please don't kick me too much, I am only doing this for a hobby after all. Thanks!!

 

[optima21]

when I was using CO2 for MIG welding, I managed to break the original gauge in litres per minute, so replaced it with a normal 0 to 100 psi pressure gauge. I found that it welded ok at 30psi (which would be about 0.2 MPa) on the gauge. Im guessing that there must be a restriction between the gauge and outlet to get a pressure reading, but that would vary between different manufacturers and gauges ( and also if the hose to to torch nozzle was restrictive. In my case it was 2.5mm bore so was restrictive to flow).

I tend to ignore the flow rates on the gauges on my regulators these days and use a peashooter gauge that goes over the torch shroud, which are available for loose change from China etc

http://www.ebay.co.uk/itm/201481172727

 

[rtbcomp]

^^ they show pressure downside of an accurately sized nozzle so they can be calibrated in flow.

+1 for a peashooter gauge.

 

[Sunny01]

peashooter!! WOW Now why didn't I think of that? Thanks a million guys!