Digital Dual Flow Argon Regulators?

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I want a good dual flow argon regulator setup for back purging stainless steel exhaust piping but also want to measure my costs.  Does any digital dual-flow argon regulator setup exist where I can measure how much gas I'm using for specific jobs?  Btw, this forum rocks!
Reply:You could instead install a large face high pressure gauge between the tank and regulator (it's wise to buy a tee and use two regs so if one side malfunctions you don't lose both like you would with a dual) so you can precisely read cylinder pressure drop and convert it to whatever metric you like.I'd look in McMaster-Carr or other industrial supplier catalogs. Western Enterprises makes any CGA fitting or pigtail you might need, Hang the gauge off a high-pressure tee between cylinder and regulators, or remote mount the whole setup with a high-pressure CGA-580 pigtail.
Reply:If you're going to use a gage to measure pressure drop to determine gas used, you will need a better gage than what comes with a flowmeter.  If you can read 10 psi off one of those, you're doing pretty good.Check out what I found... http://www.omega.com/pptst/DPG1001.htmlDigital 0-2000 psi on-scale reading, and 1 psi resolution!  You only have to drop 5 c notes to get it."Great spirits have always encountered violent oppostion from mediocre minds."  --  Albert Einstein
Reply:A 0-2000 psi gauge may or  may not hold up to 2400psi use. I've never pegged a digital gauge, but I've seen quite a few analog gauges destroyed when someone installed a gauge rated at lower pressures on a HP cylinder.Personally I use a Dwyer 0-5000 psi gauge for mixing. I think mine ran $200 when I bought it a few years back. Mine is the DPG-111, because that's what my supplier had in stock at the time. Not sure exactly what the differences are between the red faced and black faced Dwyers are with out digging into the specs.Might want to look at Dwyers DPG-110 (0-3000) or  DPG-111 (0-5000) ( $199 IIRC) or their DPG-010 (0-3000) or  DPG-011 (0-5000) ($179 IIRC)http://www.dwyer-direct.com/shop/sea...Fcp65Qodu20bMgKeep in mind with a gauge this accurate, it will pick up variations simply based on temperature changes. If you bring in a cylinder stored outside at say 14 deg in the winter to a heated shop and hook up the gauge, it will read significantly lower than it will in say 12 hrs after the cylinder has warmed up.  That means if you start out a job say at 7am in the summer when the cylinder is cool from over night, and then when you finish at 3pm the dark blue cylinder has been sitting in the sun for hours and the temp outside is now 98 deg, your calcs for gas usage will be lower than actual numbers because of gas expansion due to heat. Check the same cylinder the following morning after it say all night and cooled, and you will find the final pressure has dropped from what it was the day before a 3pm.Also keep in mind high gas flow will also drop the temp of the cylinder. It's why cylinders will frost up under certain conditions. This will give you a higher than actual usage number when you run the calcs. This probably won't be an issue in most cases because I doubt you would have a high enough flow to cause issues unless you are doing some big volume purging or running some very high gas flows thru the torch/gun.One thing you may find useful. I believe my Dwyer can be reset to zero and then measure from there. That means you might be able to simply zero the gauge at the start of the job and then read a direct drop in pressure at the end. It's not a function I ever have a need for, so I'm not 100% sure about this. I only rezero my gauge once in a great while when I need to be super accurate on certain mixes. Most times if I'm within 50 psi or so it's good enough for the mixes I need to do..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:Thanks for the input guys .  If I understand correctly, I can simply re-use my same regulator, replace the analog gauge with the digital one (DPG-010), buy a Y-fitting and secondary flow meter right?Here is what I currently have:The Red lines are where I was thinking to put a y-fitting, but does anyone know where I can find an identical flow meter?
Reply:Should work as long as there is enough room for the 2nd flow meter..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:Yikes, seems to me that the cost of your:• metering equipment• man-hours spent finding, buying, adjusting and dikking around with the metering equipment• man-hours spent doing the math to figure out how much argon you used• man-hours spent itemizing it on your bill, and then arguing over it with your customerswill cost about 100 times as much as the cost of the argon itself.What would your Return on Investment be on something like this? 100 years?Would it even be profitable at all?
Reply:A couple observations,Putting your y-fitting on the low pressure side of that regulator may demand more gas flow than it's capable of providing.  Check with the manufacturer about how much volume of gas the diaphragm and orifices in that regulator are designed to provide.  you might find that two flow meters down stream demand more than the hardware can provide.I use a T fitting on the high pressure side of my Ar tank for back purging.  I put two seperate regulator/flowmeters onto this T fitting.  I can adjust gas flow independently on each meter and there's no problem using off the shelf regulators.It'll cost you a bit more money to put the T on the high pressure side, but the added flexibility is worth it, IMO.Last note, get rid of that pipe tape on your regulator high pressure fitting.  you shouldn't need it.  The seal is made by the flared end of the tube, not the nut.  All that nut is supposed to do is provide pressure to seal the tube end against the seat on the inside of the tank gas valve.  If you have leaks, you have a bad seal on the tube, the tank valve, or you haven't tightened the nut enough to make a seal.  In any case the pipe tape is useless at best, and something to jam up the internals of your regulator at worst.  It's a bad habit to use the tape where it's not needed.  With an O2 tank it's a good way to blow yourself up as well.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:I wouldn't bother with an identical flow meter unless it's a "look pretty" issue.Search using the term "Western Enterprises T-92 Manifold Male CGA-580 Coupler Tee". Plenty of vendors online, they go around twenty dollars.For those with large gas appetites (or who have lots of cylinders and don't feel like scattering them around the shop), a few tees and pigtails let you gang your cylinders out of the way if you want to manifold your gas. Install your final pressure regulator at the last tee and connect that to the manifold.We stepped down the pressure to about 35 psi at the manifold, then plugged in individual flowmeters using pneumatic quick disconnects so each user could plug in their TIG rig and purge flowmeter if desired. Our various-brand flowmeters had no problem coping with the low input pressure.Worked great, and we could switch between a liquid argon Dewar or high-pressure cylinders (DO NOT MIX THEM or the low pressure Dewar blowoff valve will dump all your argon!) as convenient.
Reply:If you want to understand your cost, I'm not sure you want a 'flow" meter, but more of a flow counter.  Something that will tick off exactly how many CF's of argon has flowed.I have not seen such a gauge.  If you could hook up something electronically, you might be able to estimate flow rate and multiply that by the time.  Argon and CO2 are pretty close in density so you could get away with something calibrated for either.http://www.alicatscientific.com/prod...flow-meter.phpThat seems to be a high end solution.  I suspect it will cost a pretty penny (or 200000 pretty pennies) but hey, give them a call and see what they say.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Duplicate flowmeter...http://www.ebay.com/itm/320685449955"Great spirits have always encountered violent oppostion from mediocre minds."  --  Albert Einstein