"FULL"???? Oxy bottles

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Is it just around here or going on all over? Every time I hook up to a "full" oxy tank it only has 1500-1600 PSI in it? One supplier told me that they are only supposed to put 1500 PSI in a cylinder. All my cylinders are approved for 2215. It used to be a full oxy tank had 2000+ PSI in it. I feel like I am getting it up the wazoo.Joewww.CummingsHauling.com
Reply:Originally Posted by joethemechanicIs it just around here or going on all over? Every time I hook up to a "full" oxy tank it only has 1500-1600 PSI in it? One supplier told me that they are only supposed to put 1500 PSI in a cylinder. All my cylinders are approved for 2215. It used to be a full oxy tank had 2000+ PSI in it. I feel like I am getting it up the wazoo.
Reply:Cold weather will cause them to read low. If you are checking them when they are delivered or right after, they have been riding around in the open truck in cold weather. If you have them inside a warm garage for several hours, they should read higher. If not, your gas company is not filling them all the way. I always check mine after they have been in my garage for a day, and they are always 2000. Everyone needs to be keeping watch on their helium tanks at this time. There is a helium shortage and some gas distributors are not filling them full.
Reply:Another problem I've seen, when some of the less experienced firefighter/EMTs I work with fill our medical oxygen tanks (we have a cascade system in every station) is that they "fast fill" the tank.  As the pressure in the tank rises, so does the temp.  If you fill a tank too fast, it will get pretty hot because the pressure and temp are rising faster than the excess heat can be radiated off of the tank.  When the tank cools, you can loose a few hundred PSI, especially in smaller tanks, regardless of ambient temperature.  Another problem, depending on your supplier, IF they are filling on site, from a cascade system, is that they can (obviously) never get a tank completely full unless they have brand new, full cylinders that they are filling from and even then it's not guaranteed.Contact me for any metal polishing needs you may have, my avatar is a pic of a standard, painted fire axe that I ground, sanded polished and buffed to a mirror finish.
Reply:The LWS where I get my gases is only filling helium bottles for long time helium customers, and taking no new ones.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:The last two fills (most recent one, yesterday) of my "K" size argon cylinders rated at 2015 psi at my preferred LWS were 2250 psi when I checked them at home.  That means I netted 248 cu.ft..  If the cylinders had been filled to only 2015 psi, I would have netted only 222 cu.ft. of argon.  That means I got almost 12% more gas with their "overfills" compared to their competitors.  I paid $82 plus tax and haz. fee for a total of just over $96 for the most recent fill.  The grand total for a fill is up 54% in the last two years (they didn't impose haz. fees two years ago).ScottMiller XMT 350 CC/CV w/gas solenoid opt.Miller S-22A wirefeederBernard 400A "Q" gunMiller Spoolmatic 30A / WC-24C-K 200A torch/gas lensWeldcraft WC-18 watercooled torchHypertherm Powermax 30Victor O/A
Reply:I should have added that my most recent fill of an oxygen cylinder at the same LWS netted 124 cu.ft. of gas in a cylinder if filled to its rated pressure would have yielded 120 cu.ft., a gain of just over 3%.  They add haz. fees to oxygen fills as well, so with the overall increase in the price of compressed gasses, prices have gone up a bunch on oxygen too.ScottMiller XMT 350 CC/CV w/gas solenoid opt.Miller S-22A wirefeederBernard 400A "Q" gunMiller Spoolmatic 30A / WC-24C-K 200A torch/gas lensWeldcraft WC-18 watercooled torchHypertherm Powermax 30Victor O/A
Reply:i used to work for a gas plant and we would fill them to 2000psi even thought they were rated for more but like the otheres said the cold weather makes them read lower at about 70 deg above zero they will ready higher
Reply:Well I have been using oxygen for at least 30 years, and I do understand the relationship between temp and pressure ("The Ideal Gas Law"). Not to mention the adiabatic, isothermal, and isometric factors that come into play when tanks are filled.But this seems to be a trend around here. 1500 is considered a "full" bottle. I know of at least 3 suppliers that are doing it. Some say that it is against the law to put more in. I think that is BS. I think it is more like the shrinking candy bars of the 70's.Last edited by joethemechanic; 02-27-2008 at 07:53 AM.Joewww.CummingsHauling.com
Reply:Originally Posted by joethemechanicWell I have been using oxygen for at least 30 years, and I do understand the relationship between temp and pressure ("The Ideal Gas Law"). Not to mention the adiabatic, isothermal, and isometric factors that come into play when tanks are filled.But this seems to be a trend around here. 1500 is considered a "full" bottle. I know of at least 3 suppliers that are doing it. Some say that it is against the law to put more in. I think that is BS. I think it is more like the shrinking candy bars of the 70's.
Reply:It has always been 2000# around here. I haven't bought one in a while but the last one was still 2000#. Pressure in acetylene cylinders is not a reliable indication of the amount in the cylinder. It varys too much with temperature. On a very hot day you might have 350# on your guage and on a very cold day you might have 200#. Both reading on a full cylinder. I don't know what one would show where it gets really cold.
Reply:Pressure in a 'liquid' cylinder (liquid CO2, or acetylene dissolved in in acetone) depends on the type of 'stuff' in the cylinder/tank and the temperature, but will be pretty much the same pressure if there's 1 pound or gallon of liquid in the tank or 100 pounds or gallons of liquid in the tank.  Liquid tanks are done by weight or volume and not pressure.Gas cylinders/tanks are (gaseous nitrogen, argon, oxygen C25, helium, etc) filled by pressure.  The pressure does vary a little with temperature, but not drastically.1500 psi is NOT a full tank for a tank sized and rated based on 2015 psi.Dmaxer/Scott, you may have gotten a little 'extra' gas.  I doubt if it was much though.
Reply:I just hooked up a fresh one today and it had 2000 on it.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:My first fillup netted me 2050psi O2 and 230psi ACE.Miller Syncrowave 200MillerMatic 180 AutoSetHobart Airforce 500iVictor O/A (80cf)
Reply:For those of you who don't know if your tank has a + after the hydo stamp its rated to 10% over the stated presure on the tank, 2400 +'d would be rated to 2640psi. Not that they may fill them to that but they could.I dive, and if you want to know about temps changing presures I've got one for you. in Oct I filled my doubles to do a long working dive 2 hrs + at 70'. Technical divers regularly over fill certain tanks made in europe. In Europe these tanks are rated to 300 BAR or around 4200 PSI, in the US DOT limits them to 2400+ed to 2640 due to the size of the valve used. I forget what I filled them to but it was around 50 deg F when I filled them and they were FULL. Weather was bad and we didn't dive. Feb comes around and I'm getting ready for a class in florida so I have so pool time set up to check out my gear before we leave for the class. Tanks have been in the truck all night, air temp 14 deg F. While waiting for the pool to open I set up my gear and check the gauges in the parking lot. Presure reads 3200psi. Hmmm... seams kinda low but maybe the valve got bumped in storage. Oh well I don't need that much gas in the pool, I'll just check in the water to be sure the valves arn't leaking. Well we get in the pool and do equipment drills for about 2 hrs. As we get ready to get out of the pool I look at my gauges to see how much air I have to dump to refill for the trip. Gauge reads 4300psi after 2 hrs. the pool is 89 deg F! I don't even want to think how high they went when I got in the pool.BTW the burst disks in the valves go at 5600 psi the same as US tanks rated for 3242 or 3500 psi. No pluses on these tanks per DOT. Still well within the EN spects for the tanks and in europe thes tanks wouldn't even need burst disks. Hydro spects on 2400psi +ed tanks test at 4400psi. so the tanks were well below burst rating.Not that I would recomend that you fill you tanks this way.... nor do I on a regular basis. But I fill my own tanks and extra air dosen't kill technical and cave divers, LACK of AIR DOES!
Reply:Here... my place we fill it 1800 PSI... you dont get 7 cubic meter of gas but a norm 6 cubic meter take and give...Unit in my fab shop dept:my good hand and team that trust me...A lone welder make art... a village full of welder make Miracles...