TIG Welding - Shield Gas Pressure

Well, at the point it comes out of the nozzle, it is atmospheric! You need to be looking at the flow, not the pressure. The flow must be sufficient to cause a local atmosphere in the region of the weld that has a distinct absence of oxygen in it.

Have you talked to an experienced welder about this question?

no, i mean whats the pressure when it comes out of the tank and flows inside the tube?

Well, it will vary depending on the quantity of Argon left in the tank. That's what the cylinder regulator is for - to take out that variable.

You really need to talk to the person who sets the equipment up to answer this one. Get him/her to show you!

It will vary along the tube with position, and will vary at any position with flowrate. As it leaves the nozzle it is at atmospheric. Everything else is probably of academic interest only.

The max pressure of the Agron gas is usually 15kgf/cm2 for LPG tank, and 150 kgf/cm2 for compressed gas. And you have to use the regulator combined with flowmeter before the gase flowing into the TIG welding machine. And the pressure after regulator is 2~3 kgf/cm2. Therefore the pressure of shield gas is aprx. 1.5~2 kgf/cm2.

with tig welding use a regulator with a flow meter on it. This will reduce the cylinder pressure. The flow meter can then be adjusted for what ever application you are using by adjusting the knob on the side of the regulator. To much flow will waste your sheilding gas, in this case argon and can pull in atmospheric gas from the sides. Not enough flow will not properly shield the weld puddle resulting in porosity in the weld. As for the flow settings it has been a while and I cant give you a straight answer. Call any welding supplier and they will be able to tell you or email info@ramweldingsupply.com I hope this helps.

the flow meter normally is set between 25 and 30 psi With the flow meter shown read it at the top of the ball

TIG welding is normally performed from ambient atmospheric pressure to about 1.0 inch H2O above ambient. Welds made in a slightly elevated pressure are done in a glove box which is filled with inert gas. In all cases, the process is designed to be performed at, or close to atmospheric pressure.

I tend to do 20-30 cfm on carbon steel and a little higher on stainless and/or windy conditions. I find that using around 35-45 cfm on stainless seems to have a slight cooling effect and enables me to get better color from the weld. The only time I use allot of pressure is when purging really long runs of stainless I have an oxygen regulator tricked out to fit argon bottle to achieve around 10 psi. not sure why this works but it does, when I do this I use a large liquid bottle.

pipewelder

pipe welder,

did u mean 20-30 cfh instead of cfm??

Yeah I do, my bad.

piupewelder

I also meant cfh not psi. not enough coffee

Having read this thread, nobody has been able to answer the main question. What is the output pressure of the Argon regulator please? I don't need to know about flow rate and I don't need to know about the cylinder pressure, I just need to know what the maximum output pressure of the Argon regulator is please. Does anybody know?

One answer to your question is, it's a little like asking what the pressure in a water sprinkler is while you are watering. We might know that the source has a defined pressure, say 60 psi, but while the sprinkler is operating, we measure the flow rate in gallons/unit of time.

20 to 30 PSI to start. The more you weld the better you'll be at adjusting the pressure for a clean line. Adjust pressure up or down till desired seam is attained.

I am actually using a solenoid valve between my argon tank and my weld torch.

The valve needs to switch flow between 2 weld torches, alternately.

How do I size my valve? What should be my flow and pressure rating?

Thanks for all the rplies!

Irrespective of the Argon Cylinder pressure which is adjusted through the regulator the outlet flow rate controlled through the flow meter is very important for shielding. It varies depending upon the current selected metals used.

For example, for welding SS, CS, AS etc. the flow rate could be any where between 8 to 10 or 12 LPM (liters per minute) as the Tungsten Electrode size used is generally 2.00 & 2.40 mm and ampere selected is lower. Compared to it for TIG Welding of Aluminum, the electrode used is 3.20 or 4.00 mm to get good fusion and flow rate is higher to 12 to 16 LPM.

Purging is always lesser than the shielding rate and is in between 4 to 8 LPM on an average and sufficient to give quality bead at the root..

Beyond a limit & depending upon the current (amps) usage, excessive flow rate will not help for shielding or purging but goes as wastage in the atmosphere.

Sridhar.

When I was younger I laying down on a large SS wall panel fusing the seam. not wearing gloves when I stuck the filler wire to the tungsten it grounded out my pants zipper. I thought I had blown my balls off.