[CHEMA CARDENAS]

WE NEED SOMO HELP FROM ALL OF YOU FOLKS, HERE IS THE DEAL, WE ARE TRING TO RESTRICT PEAK FLOWS FROM A LINE THAT RUNS FROM FLOWMETER TO WIRE FEEDER ABOUT 30 TO 50 FEET LONG, ADD ANOTHER 25 FEET OF TORCH AND VOILA WE NEED TO CUT ON GAS CONSUMPTION, WE ARE THINKING GAS FLOW RESTRICTOR BEFORE SOLENOID VALVE IN THE WIRE FEEDER, BUT WE ALSO NEED A FAST COVERAGE ON THE 25 FT TORCH, MAYBE A .047 MM ORIFICE WILL DO.

HERE COMES THE GOOD QUESTION, ANYONE DONE THIS BEFORE AND DID IT WORK???

THINKING ABOUT MOTTS RESTRICTOR TOO.

[jakeru]

I can tell you that I installed a 1/16" diameter orifice in my TIG gas hose connection, to try and reduce a sudden rush of shielding gas I am getting every time I press down on the foot pedal to start an arc. Besides wasting gas, this sudden rush had other drawbacks... the noise was kind of annoying and it even blew out of position a small piece of metal I had carefully set up in place ready to weld at one time. No reason to have to put up with this...

Since this is a multi-process machine that does plasma cutting through the same solenoid, I didn't want the restriction there when plasma cutting, so I decided to put the restriction in the TIG gas lead. I drilled a relief in the hose fitting (where it mates on the front panel) for a cylindrical shaped plug, in which I drilled a 1/16" hole (only because that was the smallest drill bit I have.)

1/16" may have reduced the sudden rush of gas by a little bit, but not to the extent that I would prefer. And, I can still easily "max out" my flowmeter at 50 cfh if I adjust it open all the way, so I could still make it more restrictive and not really give up any range of gas flow adjustment. So, I'd like to make another orifice smaller than 1/16" to restrict it additionally. When the gas solenoid shuts off, the flow meter is "running on" for about 2.5 seconds after the solenoid turns off, so that's the quantity of extra gas that was getting suddenly whooshed out in a fraction of a second when the solenoid opened. (And my line between flowmeter and solenoid is much shorter than yours... its probably about 7'.) I think I saw a spec (not measured actual) that my flowmeter is calibrated internally to 50 psi.

If you could get a flowmeter with a lower pressure (or adjust it to regulate to a lower pressure...) then when the solenoid shuts off the flow, less pressure would get "charged up" in the line and it might be a good alternative to the restriction. Or, use it in conjunction with the restriction maybe. Just a thought.

[Otto Nobedder]

I realize this is an old post, but it's a good question.

Strip the flowmeter from a regulator/flowmeter (They're usually set to 60 or 75 psi, so you're dealing with inrush from this pressure) and place it in line between the solenoid and the stinger.

Or,

Install the flowmeter component on an adjustable regulator, and dial back the set pressure to a few psi.

Steve

[TheExpert]

Mott precision porous metal flow restrictors are reliable, cost-effective replacements for orifices, capillaries, or micro metering valves. A porous metal flow restrictor is, in effect, a multiple orifice device with many very small holes, creating a vast number of random pathways. So I think Mott is best.