c02 flow meter

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Can someone explain to me what is the difference between a regulator for c02 gas & a flow meter for c02 gas for mig welding.  Would the flow meter help me to regulate the gas any better.thanks for your help.
Reply:There are high pressure regulators and low pressure regulators.High pressure regulators can take input of 2000-3000psi from a welding tankand regulate that down to 30lbs of pressure or less which it can regulate.Some regulators cannot accept a 2000psi input. Make sure the regulator is made for a welding tank which is HIGH PRESSURE.
Reply:The MIG's flowmeter (flowgauge) is actually also a regulator but will be calibrated for a specific known orifice size, so that it can be labeled in flow, in cubic feet per hour (CFH).A true "flowmeter" (which some high end machines have or can buy separately) has a tube with a floating ball.  They are nice, but you really don't need to know the gas flow that accurately.  Indoors, I run mine about 15 CFH.  All you need is to make sure you consistantly don't get porosity, and that means you have sufficient coverage; this can be as low as 12 CFH on some gauges in still air.A CO2 cylinder, even one used for MIG welding, is not a relatively high pressure, like an oxygen tank or argon tank; it is about 500 PSI, mostly stored as a liquid in the cylinder.Last edited by MAC702; 05-10-2008 at 04:56 AM.
Reply:Originally Posted by wheelerbuffyCan someone explain to me what is the difference between a regulator for c02 gas & a flow meter for c02 gas for mig welding.  Would the flow meter help me to regulate the gas any better.thanks for your help.
Reply:I have a Smiths ball-type flowmeter on my TIG machine. I prefer the ball. I think they are more accurate and they are very easy to adjust with a visible setting.
Reply:If it doesn't have the floating ball, it is a pressure REGULATOR, whether it is labeled in PSI or CFH.A known pressure will have a predictable flow through a known orifice, which is why a REGULATOR can be used for welding gases.Because of its calibration and labelling, it's often called a flowgauge, or even a flowmeter, but it is a pressure regulator.
Reply:Originally Posted by MAC702The MIG's flowmeter (flowgauge) is actually also a regulator but will be calibrated for a specific known orifice size, so that it can be labeled in flow, in cubic feet per hour (CFH).A true "flowmeter" (which some high end machines have or can buy separately) has a tube with a floating ball.  They are nice, but you really don't need to know the gas flow that accurately.  Indoors, I run mine about 15 CFH.  All you need is to make sure you consistantly don't get porosity, and that means you have sufficient coverage; this can be as low as 12 CFH on some gauges in still air.A CO2 cylinder, even one used for MIG welding, is not a relatively high pressure, like an oxygen tank or argon tank; it is about 500 PSI, mostly stored as a liquid in the cylinder.
Reply:Originally Posted by MAC702 A CO2 cylinder, even one used for MIG welding, is not a relatively high pressure, like an oxygen tank or argon tank; it is about 500 PSI, mostly stored as a liquid in the cylinder.
Reply:Yep, I use the liquid to fill the smaller tanks for the Passport welder.As to the 12 CFH issue, that's an interesting question.  Other than lots of experience, as well as several others who also run it that low (on occasion, indoors in still air) I'll look around and see what "manufacturer's" recommendations there are that address this.Perhaps you can add why you think it is poor advice, though, more specifically?For example, what is the difference between 12 CFH indoors in still air and 20 CFH when there is a slight draft, if both give adequate shielding to prevent porosity?Last edited by MAC702; 05-12-2008 at 06:20 PM.