Tig gas flow profile

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Hello sparky,I had a friend over and as he interrupted my TIG work, I pressed him to light up.  He has much more experience than I do.  SO he lights up, tigs about 3 inches and stops.  He then queries me.  "Why is your gas flow so yucky ??"  I did not have a clue what he meant. In his world, when the machine start to flow the gas, it has a constant flow at whatever the meter is set at until the post flow form the machine. When  I use my rig., It starts with a good blast and then it dribbles down to a fairly low amount. Since it came out of the box that way, I don't know if it is a flow regulator problem or is it the inverter welding machine.  So here is the question. What controls the volume and flow rate of the TIG gas, the regulator or the inverter tig machine ??See what experience can bring out ??looking fwd to the replays.PS.. by the way.. I don't have any legs , so I use the foot pedal uder my elbow and press it down.  Do they make a trigger that I can use it on my hands ??Thanks SParkyWWoW   (Wild Welder on WHeels)
Reply::Yes they do have finger controls.Your tig machine is surging on start and perhaps dwindling due to a blockage. Please list your equipment and maybe we have a solution for you.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:the initial blast is the surging from the highish pressure in the line between the tank and the machine.  Even during the blast, the CFH should stay fairly constant, because the rush is not moving past the regulator---it's only in the post-regulator argon line.  If one of you looks at the regulator in the first few seconds after lighting up the arc, and notices that the flow actually does dwindle down, then there might be a blockage problem. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:X2 on listing your machine and agron settings. This is the obvious one; was there a breeze of any kind? Did you check the flow when he said it was "squirrelly"? Low argon bottle may cause initial surge followed by dwindiling flow as well. I used to use a regulator at the shop and the flow was all over the place. I finally got sick of it one day and replaced it with a flowmeter and problem solved. Even scratch start rigs surge the gas when you first open the gas valve. I hear them hissing all over the shop even with my earplugs in, radio on and the compressor running. Just throwing some random stuff out there…-Rgfab
Reply:Guys,Thanks for your inputs. I am usung a Longevity Invetrer machine TIG/MIG/STICK/Plasma.I acne get a good blast of argon into my face and then within 5 sec it dribbles to barley a breeze.  I know something is wrong... Byut what ??ThankWWoWMmike
Reply:Interesting way to note argon flow. Last time I checked, my flow meter didn't have a listing for " good blast in face" or "barley a breeze"... Knowing what your flow rate is set at would help. On average 15 to 20 CFH is typical without a gas lens. You can cut that in half possibly if using a gas lens and still have good coverage..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Well this is exactly where a portable flowmeter would come into play. An overly high surge, then a dribble sounds like an obstruction.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Leaving the gas cap alone, pull off the ceramic cup off, then collet body and collet with tungsten. Look inside to see if the gas  cap is threaded over the gas hole. If so, you might have let the collet body work it's way out or it is worn, or you have a crushed collet. Beyond that check with the manufacturer for piping details, as there may be a manufacturing defect.Last edited by shovelon; 08-28-2013 at 10:49 AM.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Hi Sparky'sThanks for the response.  I am trying to get the mfg to respond to my emails on this issue.again  thanks for the suggestions.Regards,WWoW"Flush OBOMA before we all go down with him"
Reply:Hello WWOW, in addition to much of the information that others have contributed here, think of this as an analogy: if you have your water hose turned on and water is flowing from the end you will have a certain amount of water coming out. If you put your finger over the end of the hose for a moment pressure will build up in the hose and when you take your finger off the end you will have a rush of water for a moment or two and the it will subside back to it's normal flow. The shielding gas coming from the regulator/flow-meter works in a very similar fashion. When gas flow stops, the pressure in the hose increases to whatever PSI that the regulator portion of the flow-meter is set to, once the solenoid is activated to provide gas flow the initial flow/pressure coming out is greater than the flow that will be present once everything has equalized. Hopefully this explanation is understandable and simple enough. Best regards, Allanaevald
Reply:To cut down on the blast, use a smaller diameter, harder hose.  I use a hard poly tubing that is a small diameter from the regulator to the unit.  Keep it as short as possible too.  This will stop the "blast.  The tubing you have is likely "ballooning" out and just as a balloon releases its pressure, the tubing is doing so as well.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT