I have a leaky flowmeter, well a new basic one would cost me $75 but i have couple extra good mig regulators(victor and smith) laying around and i dont weld tig that much to justify the 75 bucks.

so, anybody know what would be the equivalent of 15 CFM in terms of psi?

thanks.

Your Flow gauges should be marked in cubic feet /hour not psi. There may be some chart out there some place because there is no way to convert a pressure to a volume with a formula. It could be figured out but it would cost more than your $75.00

Your flow rate would need to be set up by trail and error pretty much how you set it up for any shielding gas. I know in my shop conditions change and the adjustment needs to be tweaked from time to time

there may even be a set of numbers on the flow gauge just for argon

Your Flow gauges should be marked in cubic feet /hour not psi.

Yep, my mig, tig, and other mig all use the same regulator, all are Harris with with bouncing chrome ball, Oxy-Ace is the only form of welding I can think of off hand that uses PSI style gauges.

don't now much but I took and old co2 reg and put one of the plastic flow meter dodads on it and run the co2 reg at 35psi and then fine tune the plastic flow meter to the desired flow. all used swap meet parts have about $10 in it at the most. and have a stack of flow meters in a bucket for the future. been working for many years ED

There may be some chart out there some place because there is no way to convert a pressure to a volume with a formula. It could be figured out but it would cost more than your $75.00


The crappy flow gauges provided with a 120v Lincoln/Miller wire feed machine etc. are simply a pressure regulator with a small orifice to restrict the gas flow and unlike what the peanut gallery says it is easy to find flow of the gas once you know the orifice size, type of gas and pressure. These style of gauges generally have the internal orifice size marked on the pressure gauge face or stamped on the body.

CO2, Ar and CO2-Ar mixes are all pretty similar in properties for measuring flow at lower volumes so for a quick rule of thumb a orifice of 0.026" is going to have a factor of 2/3, a orifice of 0.032" has a factor of 1, a orifice of 0.037" has a factor of 1.08 and a orifice of 0.042" has a factor of 1.23.

For example if your flow gauge has a 0.026" orifice and you dial in a pressure of 30psig you will have ~20SCFH of gas flow (30psig X a factor of 2/3). If you have a 0.026" orifice and want a flow of 15SCFH you would need to dial in a pressure of ~23psig (15SCFH/a factor of 2/3).

A true flowmeter, ie the kind with a plastic/glass tube and a floating ball is a rotameter style flow gauge and its accuracy depends on it being graduated for the medium being measured and having the inlet pressure to the tube itself at a specific value. This is the reason that most flowmeters have the pressure regulator part sealed and 50psig is pretty much the industry standard value for inlet pressure.

If you have a rotameter "plastic flow meter dodads" without markings as to what gas, pressure and whether you read the top, middle or bottom of the ball you are not measuring anything unless your setup has the correct markings for the gas you are using and the inlet pressure is correct.

The crappy flow gauges provided with a 120v Lincoln/Miller wire feed machine etc. are simply a pressure regulator with a small orifice to restrict the gas flow and unlike what the peanut gallery says it is easy to find flow of the gas once you know the orifice size, type of gas and pressure. These style of gauges generally have the internal orifice size marked on the pressure gauge face or stamped on the body.


Typically that isn't even necessary, as they commonly have the output gauge metered in CFH based on the orifice size and intended gas. The conversions are all done already, but are only accurate with the gas the gauge was designed for.

Type "Argon Flowmeter" into Ebay, and on the first page you'll always find a few imported Victor copies. Pick a seller, send them $25-30, problem solved.

Jasonmt I stand corrected and have learned something I did not know .

I was saying that I had no known way of converting pressure to volume and have been working with these things for 30 years.

I am curious where you learned this.

Jasonmt I stand corrected and have learned something I did not know .

I was saying that I had no known way of converting pressure to volume and have been working with these things for 30 years.

I am curious where you learned this.

If you wanted to do it numberically (with a formula) its a fairly straight forward fluid dynamics problem. You just need to know all the variables, gas properties, pressures, and area.

If your bored or masicistic you can solve it yourself
http://en.wikipedia.org/wiki/Fluid_dynamics

Jasonmt I stand corrected and have learned something I did not know .

I was saying that I had no known way of converting pressure to volume and have been working with these things for 30 years.

I am curious where you learned this.

If you wanted to do it numberically (with a formula) its a fairly straight forward fluid dynamics problem. You just need to know all the variables, gas properties, pressures, and area.

If your bored or masicistic you can solve it yourself
http://en.wikipedia.org/wiki/Fluid_dynamics

The lazy among us just look it up in a old Smith Equipment catalog...