MIG GAS REGULATOR advice wanted!

[A-KID]

hi all. i have a clarke 100e mig welder and has just ran out of gas. it came with two huge bottles of CO2 which would be great to use obviously, and so need a regulator to use them.
only i have no idea what i need or how to plumb it or really what it even does! i guess i need it to regulate the pressure to the welder but have no idea what pressure i need.
the need for dials makes me think i could do some damage....

i have attached some pics of what connections i need to go from and to.
can someone point me in the right direction please!?
thanks!!
Neil

 

[voipio]

One of these will do the trick:

http://www.weldequip.com/co2-conversion-kit.htm

Your existing 4mm white nylon gas pipe just goes straight into the push-fit connector that's circled in red in the advert in the link, and is at the bottom left of the image below, on the end of the black hose.

With these CO2 regulators and cylinders, the mating surface is formed between the flat end of the cylinder valve assembly, just to the left of the ruler in your first picture, and the hard washer (usually made of nylon or similar) fitted onto the mating surface shrouded by the nut below and to the left of the gauges in the image above, so you need to look after those surfaces and the washer well. It's worth keeping a couple of washers spare.

The right hand gauge in the picture is calibrated in flow rate rather than pressure, because these regulators are fitted with an internal small bore flow restrictor, so that a given pressure behind that restrictor will give the flow rate shown by the gauge, more or less. You will need to start off with the flow rate set to around 15 cubic feet per hour, or 7 litres per min in new money, so not far off the left hand stop on the right hand gauge. Bigger jobs will need higher flow rates, but not much more than twice as much, unless it's a large welder, which the Clarke isn't. There are plenty of guidelines to be found on the web.

The left hand gauge shows cylinder pressure and this will settle to around 800-900psi at around room temp i.e. not far off the left hand stop, and go down quite alarmingly on a cylinder left out in the cold. The pressure will stay more or less constant, until all the liquid CO2 has evaporated i.e. the cylinder is nearly empty, and the cylinder pressure will then decrease steadily until the cylinder is completely empty. Why those gauges go all the way up to 6000 psi beats me. A full scale of 2000 psi would give a more useful range of pointer movement.

Hope that helps.

 

[A-KID]

excellent! thanks very much for the info, thats really helpful. i asked a few hardware shops and they were clueless. i take that to the check out now!
does seem a little bit wasteful for those gauges to go so high! wouldnt have had a clue what pressure / flow rate i would have needed so would have thought it would have been way too low!
really appreciate the time you have taken to help me.