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no, like I was saying, it had to do with film manufacturing, as best I remember. ---------- > From: Esat Atikkan <atikkan@ya*.co*> > To: techdiver@aquanaut.com > Subject: Re: Isn't oxygen, oxygen? > Date: Monday, November 29, 1999 1:48 PM > > > > --- Jess Armantrout <armantrout@wo*.at*.ne*> > wrote: > > this is not correct. There are many more grades of > > oxygen and helium. > > There are lab grades with purities (and prices) you > > would not believe. For > > example, if we had to use some of the helium used in > > photgraphic processes, > > we would all take up golf. > > > > I presume U mean He used as a carrier in gas > chromatography. > > No the chromo prefix has nothing to do w/ color > photography. > > Emergency O2 has been taken off the prescription list > - Check FDA directives or call DAN > > Safe bubbles > > Esat Atikkan > > > The average person can get Medical o2 if he has a > > presciption to get it. > > This is not hard to get. > > > > Medical and aviators are identical, however, the av > > gas is guaranteed to > > have a lower dewpoint to prevent freezing at > > altitude. The med gas is > > guaranteed to meet FDA requirements. In reallity, > > they are identical, i.e., > > ABO would meet the FDA standard and USP would meet > > the dewpoint standard. > > The two gases, if fact, share the same MSDS. > > > > Ironically, in some high tech welding applications, > > the purity requirements > > for welding gas can be *greater* than that of > > breathing grades of oxygen > > > > As has been stated before, all of the oxygen comes > > from the same place. > > Cylinder prep and tracking procedures are the only > > differences. > > > > Oxygen, in and of itself is not explosive. > > > > Finally, reputable gas suppliers track lot numbers > > on both av gas and med > > o2. > > > > For much more information, see the Air Liquide and > > Air Products web pages. > > > > Trout > > > > -----Original Message----- > > From: Russ Nolet <rnolet@un*.as*.co*> > > To: p k <abyss30@ho*.co*> > > Cc: techdiver@aquanaut.com <techdiver@aquanaut.com> > > Date: Sunday, November 28, 1999 11:27 AM > > Subject: Re: Isn't oxygen, oxygen? > > > > > > >Yes, O2 is O2 (almost!). The highest quality O2 > > that is available is > > >Medical Grade, but the average person cannot get > > it. The next grade of O2 > > >is Avation Grade. I do not know for sure exactly, > > but is most likely > > >extremely similar in quality to medical except is > > not certified medical > > >grade (this is what I use to mix my gas). The > > poorest quality is welding > > >grade, which is not monitored at all for quality, > > and is not required to be > > >filtered to remove particulate matter. From a > > welding perspective the > > >percentage of O2 in the tank is really not that > > critical. > > > > > >There are also different grades of helium. The > > lowest grade is that which > > >is used for filling helium balloons, and should be > > avoided for diving > > >purposes, welding grade which is the next step up > > is similar to welding > > >grade O2 in quality. Military or medical grade > > helium is the one to use > > >because the gas is filtered and cylinders are > > controlled for quality of > > gas. > > > > > >The explosion/fire risk is essentially the same for > > each grade of O2. You > > >are probably correct, most welders do not wash > > their hands, but the risk of > > >fire/explosion from changing an O2 reg with dirty > > hands is probably nill. > > >O2 is explosive when exposed to hydrocarbons at > > high pressure, any O2 > > >leaking from the reg or bottle valve is immediately > > reduced to 1atm and > > >diluted in the ambient atmosphere. > > > > > >An interresting anecdote: I am an engineer for a > > company that designs > > custom > > >test machinery to inspect for leaks in vessiles > > (gas tanks, evaporator > > >cores, a/c compressors, etc...), we use a > > technology called Helium Mass > > >Spectrometry, where we fill the test object with > > helium tracer gas and > > >"look" for heluim outside the test object. A while > > back, I was starting up > > >a machine I designed, and I connected a Nitrogen > > tank to the test object to > > >confirm the machine cycle before introducing the > > helium which sometimes > > >causes another set of problems. This time I kept > > getting what appeared to > > >be minor heluim leaks from the test opject. After > > several hours, I > > >determined that the nitrogen tank contained helium > > gas even though the > > >bottle was the correct paint color to indicate > > nitrogen. The most > > important > > >thing to be aware of when buying your own gas for > > mixing is to know what > > you > > >are getting, and welding grade gasses are not > > controlled to the same degree > > >that the avation grades are. > > > > > >Russ Nolet > > > > > >----- Original Message ----- > > >From: p k <abyss30@ho*.co*> > > >To: <techdiver@aquanaut.com> > > >Sent: Saturday, November 27, 1999 8:05 PM > > >Subject: Isn't oxygen, oxygen? > > > > > > > > >> This question has plagued me for a while. > > >> What is the difference between breathing oxygen > > and welding oxygen? > > >> > > >> First,I was told that welding O2 had more > > hydrocarbons contained in > > >> it, BUT isn't the explosion/fire risk the same? > > How many auto mechanics > > >wash > > >> and dry there hands before changing a regulator > > on an > > >> oxy-acetylene torch? The second thing I was told > > is "there is possibly a > > >> higher moisture content", to me that doesn't hold > > up either because > > oxygen > > >> (commercial grade) will always come in a steel > > cylinder, if there is any > > >> moisture in there it will rust and pretty quickly > > I might add. So what's > > >the > > >> deal? Anybody? > > >> > > >> > > > ______________________________________________________ > > >> Get Your Private, Free Email at > > http://www.hotmail.com > > >> -- > > >> Send mail for the `techdiver' mailing list to > > `techdiver@aquanaut.com'. > > >> Send subscribe/unsubscribe requests to > > `techdiver-request@aquanaut.com'. > > >> > > > > > >-- > > >Send mail for the `techdiver' mailing list to > > `techdiver@aquanaut.com'. > > >Send subscribe/unsubscribe requests to > > `techdiver-request@aquanaut.com'. > > > > > > -- > > Send mail for the `techdiver' mailing list to > > `techdiver@aquanaut.com'. > > Send subscribe/unsubscribe requests to > > `techdiver-request@aquanaut.com'. > > > > __________________________________________________ > Do You Yahoo!? > Thousands of Stores. Millions of Products. All in one place. > Yahoo! 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