mig gas pressure

By 522029

Date 01-14-2010 12:25

Flow, not pressure. The flow should be around 20 to 30 CFH.

Griff

By welderbrent (*****)

Date 01-14-2010 14:21 Edited 01-20-2010 14:33

thewelderson,

WELCOME TO THE AWS FORUM!!! Hope you enjoy the info and opportunities available here.

A lot of companies are now selling 'pressure' gauges instead of flow meters for regulating gas shielding. They work fine for the average Joe in his garage doing hobby work. They are cheaper supposedly, especially than 'GOOD' flow meters.

But, for code work you will find things listed according to flow. The perameters should be checked according to the WPS you are working to, the manufacturer's recommended practices, and any code restrictions.

The previous poster is right in there on the average recommended flow rate. It can be up or down 'slightly' for some variables.

There is a ratio relationship between the pressure and flow, I just don't remember it currently. Seems as though 15 psi is about where you would want to be if you are working with pressure regulators. (Lord save me from these guys if my mind is taking a senior moment).

Interesting, where did the end of my post go? I know I had typed more than that. Can't even remember what it was now but I know I had my exit greeting there, SO-

Have a Great Day, Brent

By ssbn727 (*****)

Date 01-14-2010 14:54

Hi Brent!

Now you got me curious... Would you mind saying which of these "companies" are now selling their "everything included" MIG (GMAW) packages that include a pressure regulator as opposed to a flow meter? I ask this because I would like to personally contact them to make sure that they stop embarrassing themselves by offering them instead of what they should include in these packages and also inform them that there are enough CGA manufacturing companies of both types of regulators where the price differential between the two components would be unnoticeable to their own profit margins. ;) I mean that is just plain shortsighted on their part!

Oh and BTW, Welderson! "Weldcome to the World's Greatest Welding Forum Also!!! :) :) :) "

Respectfully,
Henry

By aevald

Date 01-14-2010 18:42

Hello Henry, for quite some time various suppliers of machines and low-cost gauges have been using "pressure" regulators that are also equipped with specific diameter orifices to accomodate specific gases, usually CO2 or 75/25(Ar,Co2). They are definitely not "flowmeters", instead they rely on a specific density of gas passing through an orifice that is sized to provide a particular flow rate at a given pressure. I don't believe accuracy really enters into the picture, especially if you are trying to "calibrate" the flow. If you run into one of these units, look at the gauge(s) on it, you may find some fine print that discusses the orifice diameter and the gas it is designed to be used with. My $.02. Best regards, Allan

By welderbrent (*****)

Date 01-14-2010 22:39

Henry,

While Allan explained the main point really well, by "companies" I should have stated 'Local Welding Suppliers'. I don't know if you could say any of these come from Miller or Lincoln, etc. BUT, when receiving a new machine from my local supplier they generally include a 'pressure' gauge. In our small area, sometimes it is difficult to find a flow meter without ordering it. Few are on the shelves.

Sorry for any confusion.

Have a Great Day, Brent

By thewelderson (*)

Date 01-14-2010 18:57

Thanks to all for the welcome.

I do have a flow meter, so I do stand corrected in that I'm looking for the flow setting, not pressure. Some old welding books my father has does confirm 30cfh, but it just seemed a bit high for indoor welding.

Thanks-Lou
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By Metarinka (****)

Date 01-14-2010 21:55

indoor you can get away with as low as 15 CFH if it's still air, I usually set it around 18, run a test bead or two and go from there.