Argon syphoning

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I have a small argon cylinder and was wondering how to syphon gas from another cylinder
Reply:Uh. .just get it filled from a lws
Reply:The term you are looking for is transfilling.They do sell argon/inert gas transfill whips. Basically you hook up one cylinder to another and open all the valves. The cylinders equalize in pressure and then you close all the valves.Rather than retype what I've done before, I'll jsut copy paste that info and see if it helps explain things for you.http://weldingweb.com/vbb/showthread.php...a-tank-at-homeFrom my 1st post in that thread....To a certain degree the answer is yes. It is possible to build a transfill whip to do what you propose however... (Read the rest below real carefully) I used to build this sort of equipment on a regular basis for diving so I know exactly whats involved.I'll simply copy my responce from the exact same question that was posted up in the past.http://weldingweb.com/vbb/showthread.php...light=transfil Originally Posted by DSWYes it's possible with a few issues that need to be addressed.One: Unless you know 100% what you are doing NEVER TRY THIS WITH O2!! If you get even the least bit of oil, dirt or other contaminant in the valve or transfill whip it will blow up on you. Like as in killed dead. This is not an area to be cheap on. I doubt you want to do O2 but it's for others that might think this is a good idea. It's not.Note it will cost you a fair amount to build a transfer whip to do inert gas. All parts must be rated to at least 3000 psi. Your 2 inert gas nipples and nuts will set you back probably $30-50, You'll need a couple HP couplings, about another $15 last time I got some, and then the HP line. The last one I got set me back about $50. You will need some sort of bleeder to relieve the pressure in the line so you can unhook it. These are not standard parts that are easy to locate. The only simple ones I'm aware of come from the supplier I get SCUBA stuff from. They run $100 each. A HP tee and HP valve would work also but will end up costing as much or more. So you end up with close to $150-200 in parts... Oh and if you try and go "cheap" with standard pipe fittings... Remember they will act like a grenade when they blow since at best they are rated at 150 psi and you are standing at ground zero. And they WILL blow, no ifs, ands or buts! There's a good reason HP fittings are not cheap.Oh now it gets good. Cylinders equalize in pressure, not volume. So if you want to "fill" a 20cf from a 200cf ( a 200 makes my math easier to work out) you can't just subtract 20 from 200, then 20 from 180 and so on. (thats assuming pressure on the 200 is at max to start and not 1/2 full) The 1st "fill will get you about 18 cf if the fill is done very slow so the cyl stay at the same temp. Note the small cyl will heat up as the gas is compressed so in reality you get maybe 16cf. The next one will only get you maybe 13cf. by "fill" #4 you would be lucky to get 8 cf in the 20 and thats assuming best conditions the 20 is dead empty and the 200 was only used to fill the 20cf cyl. The numbers are slightly better if the big cylinder is larger, say a 282cf, but you only get maybe 2 more fills at best. If the bigger cyl was a 100cf it's much worse and you won't get more than 2 so so fills at best.That means for your $150-200 expenditure,+ $30 fill on the large cylinder, you get one semi good fill, 2 so so fills and one that won't get you 1/2 and hour of weld time. For the same $200 lets say, you'd have gotten 10 perfect fills. A better option is to get a 2nd larger cylinder and use the 20 only when you have no other choice. In that case that same $200 in gas would have netted you 6 times the gas that getting the small cyl would have gotten you if you swapped, vs the 4 fills you got in partial amounts transfilling.I mix gas for diving and I have to do this regularly in remote locations. It's very inefficient and not usually cost effective, but it's the only option some times. The only way to make this work well is to have several large cylinders and cascade from each as the pressure drops. That adds a lot of cost and some more waste as you dump lines between swaps. For most this is a very poor way to "save" money.
Reply:Thanks. It costs $15 a month to keep an argon cylinder in Australia.  Plus the price of the gas when you change over the cylinder.  For a home garage its simply not worth it