Welding grade O2 (again)

denzel · 8th November 2006, 22:35

From my old welding days.....
IIRC the O2 is the same for welding grade and medical, but the difference is in the procedures. The medical O2 get's drained and filled from zero, and welding O2 they just top up on whatever was in there.

Denz.

Dutchy · 8th November 2006, 22:36

@Gill Envie
You might have a point there since mil spec aviation oxygen has some 200 times less water in it. What I'd like to know though is whether that's theory or experience?

***sadave*** · 9th November 2006, 00:55

Quote: (Originally Posted by denzel)

From my old welding days.....
IIRC the O2 is the same for welding grade and medical, but the difference is in the procedures. The medical O2 get's drained and filled from zero, and welding O2 they just top up on whatever was in there.

Denz.

And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back...

Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled.
Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually.

My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again...

I know what o2 I use, and its not welding grade.

ps, I have nothing against tradies, I just know too many of them!!!

silent running · 9th November 2006, 02:56

Quote: (Originally Posted by PeteS)

Regarding Argon in Welding O2 being a problem, I seem to remember that the O2 on some live aboards is 97%, and they all say it's no problem. So I'm in the welding gas camp. As opposed to the camp welding gas, which is only for bent divers.......

It does make you wonder what's in that other 3% though.

As for the topping up vs. emptying and checking each time it seems the scenerio posed by Dave is plausible and worrysome. I had the whole O2 side of my rig replaced after my first trip to Indonesia, somehow water had got into the O2 and took out $300 worth of parts. I can just see the empty O2 cylinder sitting, valve open, in the rain on the muddy ground of some construction site...

jhaaja · 9th November 2006, 08:53

Quote: (Originally Posted by sadave)

And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back...

Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled.
Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually.

My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again...

I know what o2 I use, and its not welding grade.

ps, I have nothing against tradies, I just know too many of them!!!

All industrial gas cylinder valves I have seen have spring vlaves inside. It shuts the valve when the pressure drops to 1,52bar. That way no dirt can get in.

You all have to remember that O2 is made from air. So there can not be much bad gas in it if the air was pure.

I have allways used industrial 2.5 O2 (99,5% O2) from Messer, they come in nice 300Bar cylinders

steevke · 9th November 2006, 09:55

Quote: (Originally Posted by Gill Envy)

so how true is the increase in moisture content cliam for welding O2...how big of an issue would a higher moisture content be for a steel tank...i've seen them rust so bad they have to get chucked...and at $250 a tank, the difference in cost between welding and aviation O2 could fast become moot, no?

Seeing that I get delivered my welding O2 in steel cylinders (and some of them are over 25 years old), I would not worry about moisture in the gas.

steven

jaap · 9th November 2006, 10:07

Quote: (Originally Posted by sadave)

And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back...

Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled.
Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually.

My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again...

I know what o2 I use, and its not welding grade.

ps, I have nothing against tradies, I just know too many of them!!!

I only use 'Breathing Oxygen'-quality or occasionally Analytical 5.0 O2.

But I can't resist to ask one thing. If welders abuse their cylinders so badly how come there are not more O2 fire accidents? Or do you also argue that the risk of O2 fires is exagerated ;-)

***Beanie*** · 9th November 2006, 10:09

Quote: (Originally Posted by jaap)

I only use 'Breathing Oxygen'-quality or occasionally Analytical 5.0 O2.

But I can't resist to ask one thing. If welders abuse their cylinders so badly how come there are not more O2 fire accidents? Or dou you also argue that the risk O2 fires is exagerated ;-)

non-return valves?

jaap · 9th November 2006, 10:25

Quote: (Originally Posted by jhaaja)

All industrial gas cylinder valves I have seen have spring vlaves inside. It shuts the valve when the pressure drops to 1,52bar. That way no dirt can get in.

You all have to remember that O2 is made from air. So there can not be much bad gas in it if the air was pure.

I have allways used industrial 2.5 O2 (99,5% O2) from Messer, they come in nice 300Bar cylinders

Hi

Would these "spring valves" only sit on Industrial cylinders? I would imagine that vaccuming an empty cylinder would be difficult with that sort of thing on it?

What I have seen on some cylinders is a "peg"-connecting to a one way valve inside the cylinder valve. This functions so as to not allow any gas to _enter_ the cylinder if the correct filling hose complete with a corresponding "peg"-pusher is not used. It serves to avoid gas entering an empty cylinder with an open valve or to have backpressure gas go into the cylinder during use with a std regulator.

Another function of this arangement is probably to make it harder for people to intentionally refill/remix into these cylinders. Ofcourse a determined person can bypass this function

Ben Field · 9th November 2006, 12:02

Quote: (Originally Posted by Beanie)

Air products

no idea on BOC pricing

Well when I asked it was around £150 (alll in) and you had to collect, the monthly rental was huge too like £40+ seeing a J will last me a year it'll cost £5 litre by the time I send it back :-(

Getting O2 seems to be all about who you know, whether you catch the Supplier on a good day and for how long you've been buying.

I live in Essex, I keep hearing that there is a supplier who will lend you the J's rental free.. can I find them/will someone tell me? NO, because I only want one and I'll have it for months and months.

I know they are in business to make money not "help divers" but they don't go out of their way to advertise in any way, "word of mouth" is so 1970's way of doing business IMVHO!

8th November 2006, 22:35	#21 (permalink)
denzel Holiday diver Current Rebreather/s: Inspiration Classic Other Rebreather/s: Not Bought Yet Join Date: Aug 2005 Location: Perth! Posts: 358	Re: Welding grade O2 (again) From my old welding days..... IIRC the O2 is the same for welding grade and medical, but the difference is in the procedures. The medical O2 get's drained and filled from zero, and welding O2 they just top up on whatever was in there. Denz. __________________ My deepest so far, 558.50 mtr, my rig a LF90D...
(Offline)

8th November 2006, 22:36	#22 (permalink)
Dutchy Rene Warries Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: Apr 2006 Location: Nieuwegein (The Netherlands) Posts: 844	Re: Welding grade O2 (again) @Gill Envie You might have a point there since mil spec aviation oxygen has some 200 times less water in it. What I'd like to know though is whether that's theory or experience? __________________ = This post is environmentally friendly. It is composed of 100% recycled electrons only. = Last edited by Dutchy : 8th November 2006 at 22:37. Reason: Had to point who this was adressed to. Denzel prevented me from posting right under his post ;)
(Offline)

9th November 2006, 00:55	#23 (permalink)
*sadave* Administrator Current Rebreather/s: Sport Kiss Other Rebreather/s: Not Bought Yet Classic Kiss Join Date: Jun 2005 Location: Brisbane, Queensland Posts: 1,131	Re: Welding grade O2 (again) Quote: (Originally Posted by denzel) From my old welding days..... IIRC the O2 is the same for welding grade and medical, but the difference is in the procedures. The medical O2 get's drained and filled from zero, and welding O2 they just top up on whatever was in there. Denz. And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back... Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled. Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually. My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again... I know what o2 I use, and its not welding grade. ps, I have nothing against tradies, I just know too many of them!!! __________________ Wave!
(Offline)

9th November 2006, 02:56	#24 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,873	Re: Welding grade O2 (again) Quote: (Originally Posted by PeteS) Regarding Argon in Welding O2 being a problem, I seem to remember that the O2 on some live aboards is 97%, and they all say it's no problem. So I'm in the welding gas camp. As opposed to the camp welding gas, which is only for bent divers....... It does make you wonder what's in that other 3% though. As for the topping up vs. emptying and checking each time it seems the scenerio posed by Dave is plausible and worrysome. I had the whole O2 side of my rig replaced after my first trip to Indonesia, somehow water had got into the O2 and took out $300 worth of parts. I can just see the empty O2 cylinder sitting, valve open, in the rain on the muddy ground of some construction site...
(Offline)

9th November 2006, 08:53	#25 (permalink)
jhaaja Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Mar 2005 Location: Finland Posts: 885	Re: Welding grade O2 (again) Quote: (Originally Posted by sadave) And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back... Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled. Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually. My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again... I know what o2 I use, and its not welding grade. ps, I have nothing against tradies, I just know too many of them!!! All industrial gas cylinder valves I have seen have spring vlaves inside. It shuts the valve when the pressure drops to 1,52bar. That way no dirt can get in. You all have to remember that O2 is made from air. So there can not be much bad gas in it if the air was pure. I have allways used industrial 2.5 O2 (99,5% O2) from Messer, they come in nice 300Bar cylinders
(Offline)

9th November 2006, 09:55	#26 (permalink)
steevke Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Sport Kiss Join Date: Jul 2005 Location: Belgium Posts: 317	Re: Welding grade O2 (again) Quote: (Originally Posted by Gill Envy) so how true is the increase in moisture content cliam for welding O2...how big of an issue would a higher moisture content be for a steel tank...i've seen them rust so bad they have to get chucked...and at $250 a tank, the difference in cost between welding and aviation O2 could fast become moot, no? Seeing that I get delivered my welding O2 in steel cylinders (and some of them are over 25 years old), I would not worry about moisture in the gas. steven
(Offline)

9th November 2006, 10:07	#27 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 473	Re: Welding grade O2 (again) Quote: (Originally Posted by sadave) And therein lies the problem... Was discussing this with a friend of Dad's who works for BOC a few years back... Medical o2 cylinders are drained, valve pulled, inspected, evacuated, then filled. Welding o2 cylinders are topped up. The valve gets pulled and the cylinder checked annually. My question is this... We've all seen "tradies" in action. How much do you trust the local plumber with his arse crack hanging out the back of his shorts, and a cigarette in his mouth welding pipes while standing in raw sewage? Every plumber I know, see's that his oxy is down to 20bar, goes and gets another cylinder, keeping the one he has, until its drained to zero. (despite the size of the afore-mentioned arse crack, they are all tight-arses!!!) He then swaps the cyl's over, chucks the empty one in the dirt, continues the job, then heaves the empty cylinder in the back of the ute, where it sits there for probably a week or so till he takes it back to BOC. And coz he drained it to zero, he more than likely left the valve open when he took the reg off, and it stayed that way till BOC fill it again... I know what o2 I use, and its not welding grade. ps, I have nothing against tradies, I just know too many of them!!! I only use 'Breathing Oxygen'-quality or occasionally Analytical 5.0 O2. But I can't resist to ask one thing. If welders abuse their cylinders so badly how come there are not more O2 fire accidents? Or do you also argue that the risk of O2 fires is exagerated ;-) __________________ My initials: JAAP Last edited by jaap : 9th November 2006 at 13:43.
(Online)

9th November 2006, 10:09	#28 (permalink)
*Beanie* Gallery Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,311	Re: Welding grade O2 (again) Quote: (Originally Posted by jaap) I only use 'Breathing Oxygen'-quality or occasionally Analytical 5.0 O2. But I can't resist to ask one thing. If welders abuse their cylinders so badly how come there are not more O2 fire accidents? Or dou you also argue that the risk O2 fires is exagerated ;-) non-return valves? __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
(Offline)

9th November 2006, 10:25	#29 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 473	Re: Welding grade O2 (again) Quote: (Originally Posted by jhaaja) All industrial gas cylinder valves I have seen have spring vlaves inside. It shuts the valve when the pressure drops to 1,52bar. That way no dirt can get in. You all have to remember that O2 is made from air. So there can not be much bad gas in it if the air was pure. I have allways used industrial 2.5 O2 (99,5% O2) from Messer, they come in nice 300Bar cylinders Hi Would these "spring valves" only sit on Industrial cylinders? I would imagine that vaccuming an empty cylinder would be difficult with that sort of thing on it? What I have seen on some cylinders is a "peg"-connecting to a one way valve inside the cylinder valve. This functions so as to not allow any gas to _enter_ the cylinder if the correct filling hose complete with a corresponding "peg"-pusher is not used. It serves to avoid gas entering an empty cylinder with an open valve or to have backpressure gas go into the cylinder during use with a std regulator. Another function of this arangement is probably to make it harder for people to intentionally refill/remix into these cylinders. Ofcourse a determined person can bypass this function __________________ My initials: JAAP Last edited by jaap : 9th November 2006 at 13:45. Reason: spelling
(Online)

9th November 2006, 12:02	#30 (permalink)
Ben Field CK+Shearwater Current Rebreather/s: Classic Kiss Other Rebreather/s: Sport Kiss Join Date: Aug 2005 Location: London, England Posts: 1,775	Re: Welding grade O2 (again) Quote: (Originally Posted by Beanie) Air products no idea on BOC pricing Well when I asked it was around £150 (alll in) and you had to collect, the monthly rental was huge too like £40+ seeing a J will last me a year it'll cost £5 litre by the time I send it back :-( Getting O2 seems to be all about who you know, whether you catch the Supplier on a good day and for how long you've been buying. I live in Essex, I keep hearing that there is a supplier who will lend you the J's rental free.. can I find them/will someone tell me? NO, because I only want one and I'll have it for months and months. I know they are in business to make money not "help divers" but they don't go out of their way to advertise in any way, "word of mouth" is so 1970's way of doing business IMVHO! __________________ Know your PPO2, Pre-breath, Use checklists, Validate cells at 6mtrs, Use pure O2 at or near surface, Use a BOV, Don't dive Solo, Change Slime and Cells as recommended by Manufacturer and RTFM! Beware Fridge Suck! www.hugsac.org.uk
(Offline)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode