Mailing List Archive Mailing List Archive
--- 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! Shopping: http://shopping.yahoo.com -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
Navigate by Author:
[Previous]
[Next]
[Author Search Index]
Navigate by Subject:
[Previous]
[Next]
[Subject Search Index]
[Send Reply] [Send Message with New Topic]
[Search Selection] [Mailing List Home] [Home]