Welding grade O2 (again)

Andy M · 8th November 2006, 15:03

Quote: (Originally Posted by Beanie)

What?
£52 for one inc VAT and Handling and energy charge (more makes it less) + rental of course
< 1p per litre

Is that 200 bar?

I have seen some dive shops with 250 bar J cylinders of O2, where did they get these from at a sensible price?

Andy

***Beanie*** · 8th November 2006, 15:04

Quote: (Originally Posted by Andy M)

Is that 200 bar?

I have seen some dive shops with 250 bar J cylinders of O2, where did they get these from at a sensible price?

Andy

yeah 200bar

250 is BOC I think but they don't liek us having O2

Andy M · 8th November 2006, 15:06

Quote: (Originally Posted by Beanie)

yeah 200bar

250 is BOC I think but they don't liek us having O2

Hmm. 200 bar diving grade at 52 quid? Who from?

Any idea how much for the 250 bar BOC?

***Beanie*** · 8th November 2006, 15:28

Quote: (Originally Posted by Andy M)

Hmm. 200 bar diving grade at 52 quid? Who from?

Any idea how much for the 250 bar BOC?

Air products

no idea on BOC pricing

**Gill Envy** · 8th November 2006, 15:35

in these parts it seems that the consensus is aviation grade is pretty much on par with medical grade but that welding grade may not be as dry or free of contaminants. I've heard it argued both ways.

Woz · 8th November 2006, 17:22

Welding O2 £6.30 for a 200 bar J.

Andy M · 8th November 2006, 17:30

Quote: (Originally Posted by Woz)

Welding O2 £6.30 for a 200 bar J.

Thats cheap!

I am primarily interested in higher pressure O2 cylinders though, ones that are 250 bar or so.

Whats the cheapest 250bar O2 J suitable for rebreather diving?

Dutchy · 8th November 2006, 18:59

Why the concearn? When I look up Oxygen 2.5 (intended for welding and cutting) I find it should be >99.5% O2 and 1500 (volume) parts per million H20. The rest is claimed to be Nitrogen (I don't care) and Argon. Worst case 100 - 99.5 - 0.15 - 0 = 0.35% is argon (assuming N2 is zero so all is Argon contribution)

As argon is not used it will built up in your loop. Assuming you loose none you'll collect 0.35 * 1/100 * 1000 ml = (an approximate) 1/3 of a ml/minute at an oxygen flow rate of 1liter/minute. To give you an idea that's 60 ml after a 3 hour dive.
Is that a problem? (we all know you shouldn't breath Argon)
Assuming the total loop capacity is only 6l (Which is once more a worst case since you have the 4l breathing bag and 2l of other space such as open space in scrubber, tubes and dead space in our throat and lungs etc) this gives us a fraction of 60/6000= 1%

Right so in a worst case situation you'll have a fraction of 1%. At what depth does that become a problem?

I'd argue that my personal limit is 30 meter on normal Air. With Argon being 2.33 times as narcotic I'd argue that my new limit becomes:
79*30/2.33 = 1017m

That is such an absurd number that I don't consider Argon to be problem. So what is? Are there substances in the parts per million/billion range that have an effect?

PeteS · 8th November 2006, 19:22

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.......

**Gill Envy** · 8th November 2006, 20:40

Quote: (Originally Posted by Dutchy)

Why the concearn? When I look up Oxygen 2.5 (intended for welding and cutting) I find it should be >99.5% O2 and 1500 (volume) parts per million H20. The rest is claimed to be Nitrogen (I don't care) and Argon. Worst case 100 - 99.5 - 0.15 - 0 = 0.35% is argon (assuming N2 is zero so all is Argon contribution)

As argon is not used it will built up in your loop. Assuming you loose none you'll collect 0.35 * 1/100 * 1000 ml = (an approximate) 1/3 of a ml/minute at an oxygen flow rate of 1liter/minute. To give you an idea that's 60 ml after a 3 hour dive.
Is that a problem? (we all know you shouldn't breath Argon)
Assuming the total loop capacity is only 6l (Which is once more a worst case since you have the 4l breathing bag and 2l of other space such as open space in scrubber, tubes and dead space in our throat and lungs etc) this gives us a fraction of 60/6000= 1%

Right so in a worst case situation you'll have a fraction of 1%. At what depth does that become a problem?

I'd argue that my personal limit is 30 meter on normal Air. With Argon being 2.33 times as narcotic I'd argue that my new limit becomes:
79*30/2.33 = 1017m

That is such an absurd number that I don't consider Argon to be problem. So what is? Are there substances in the parts per million/billion range that have an effect?

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?

8th November 2006, 15:03	#11 (permalink)
Andy M Dude Current Rebreather/s: Home Build Other Rebreather/s: Sport Kiss Home Build Join Date: Mar 2005 Location: Cambridge, UK Posts: 424	Re: Welding grade O2 (again) Quote: (Originally Posted by Beanie) What? £52 for one inc VAT and Handling and energy charge (more makes it less) + rental of course < 1p per litre Is that 200 bar? I have seen some dive shops with 250 bar J cylinders of O2, where did they get these from at a sensible price? Andy __________________ Know your PO2 at all times
(Online)

8th November 2006, 15:04	#12 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,247	Re: Welding grade O2 (again) Quote: (Originally Posted by Andy M) Is that 200 bar? I have seen some dive shops with 250 bar J cylinders of O2, where did they get these from at a sensible price? Andy yeah 200bar 250 is BOC I think but they don't liek us having O2 __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk 0871 242 7808
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8th November 2006, 15:06	#13 (permalink)
Andy M Dude Current Rebreather/s: Home Build Other Rebreather/s: Sport Kiss Home Build Join Date: Mar 2005 Location: Cambridge, UK Posts: 424	Re: Welding grade O2 (again) Quote: (Originally Posted by Beanie) yeah 200bar 250 is BOC I think but they don't liek us having O2 Hmm. 200 bar diving grade at 52 quid? Who from? Any idea how much for the 250 bar BOC? __________________ Know your PO2 at all times
(Online)

8th November 2006, 15:28	#14 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,247	Re: Welding grade O2 (again) Quote: (Originally Posted by Andy M) Hmm. 200 bar diving grade at 52 quid? Who from? Any idea how much for the 250 bar BOC? Air products no idea on BOC pricing __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk 0871 242 7808
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8th November 2006, 15:35	#15 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,326	Re: Welding grade O2 (again) in these parts it seems that the consensus is aviation grade is pretty much on par with medical grade but that welding grade may not be as dry or free of contaminants. I've heard it argued both ways. __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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8th November 2006, 17:22	#16 (permalink)
Woz Custom Title Allowed! Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: Jun 2005 Location: Nottingham Posts: 185	Re: Welding grade O2 (again) Welding O2 £6.30 for a 200 bar J. __________________ Still punting shiny diving tatt to gullible divers www.kitfondle.co.uk
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8th November 2006, 17:30	#17 (permalink)
Andy M Dude Current Rebreather/s: Home Build Other Rebreather/s: Sport Kiss Home Build Join Date: Mar 2005 Location: Cambridge, UK Posts: 424	Re: Welding grade O2 (again) Quote: (Originally Posted by Woz) Welding O2 £6.30 for a 200 bar J. Thats cheap! I am primarily interested in higher pressure O2 cylinders though, ones that are 250 bar or so. Whats the cheapest 250bar O2 J suitable for rebreather diving? __________________ Know your PO2 at all times
(Online)

8th November 2006, 18:59	#18 (permalink)
Dutchy Rene Warries Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: Apr 2006 Location: Nieuwegein (The Netherlands) Posts: 762	Re: Welding grade O2 (again) Why the concearn? When I look up Oxygen 2.5 (intended for welding and cutting) I find it should be >99.5% O2 and 1500 (volume) parts per million H20. The rest is claimed to be Nitrogen (I don't care) and Argon. Worst case 100 - 99.5 - 0.15 - 0 = 0.35% is argon (assuming N2 is zero so all is Argon contribution) As argon is not used it will built up in your loop. Assuming you loose none you'll collect 0.35 * 1/100 * 1000 ml = (an approximate) 1/3 of a ml/minute at an oxygen flow rate of 1liter/minute. To give you an idea that's 60 ml after a 3 hour dive. Is that a problem? (we all know you shouldn't breath Argon) Assuming the total loop capacity is only 6l (Which is once more a worst case since you have the 4l breathing bag and 2l of other space such as open space in scrubber, tubes and dead space in our throat and lungs etc) this gives us a fraction of 60/6000= 1% Right so in a worst case situation you'll have a fraction of 1%. At what depth does that become a problem? I'd argue that my personal limit is 30 meter on normal Air. With Argon being 2.33 times as narcotic I'd argue that my new limit becomes: 79*30/2.33 = 1017m That is such an absurd number that I don't consider Argon to be problem. So what is? Are there substances in the parts per million/billion range that have an effect? __________________ = This post is environmentally friendly. It is composed of 100% recycled electrons only. =
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8th November 2006, 19:22	#19 (permalink)
PeteS Consent Issued! Current Rebreather/s: Inspiration Classic Inspiration Vision Other Rebreather/s: Join Date: Jun 2005 Location: New Zealand Posts: 531	Re: Welding grade O2 (again) 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....... __________________ Pete S. http://www.steggle.co.nz Every silver lining has a cloud
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8th November 2006, 20:40	#20 (permalink)
Gill Envy Shearwater Copis Divers Current Rebreather/s: Other CCR Other Rebreather/s: Evolution Other CCR Join Date: Nov 2005 Location: seattle Posts: 1,326	Re: Welding grade O2 (again) Quote: (Originally Posted by Dutchy) Why the concearn? When I look up Oxygen 2.5 (intended for welding and cutting) I find it should be >99.5% O2 and 1500 (volume) parts per million H20. The rest is claimed to be Nitrogen (I don't care) and Argon. Worst case 100 - 99.5 - 0.15 - 0 = 0.35% is argon (assuming N2 is zero so all is Argon contribution) As argon is not used it will built up in your loop. Assuming you loose none you'll collect 0.35 * 1/100 * 1000 ml = (an approximate) 1/3 of a ml/minute at an oxygen flow rate of 1liter/minute. To give you an idea that's 60 ml after a 3 hour dive. Is that a problem? (we all know you shouldn't breath Argon) Assuming the total loop capacity is only 6l (Which is once more a worst case since you have the 4l breathing bag and 2l of other space such as open space in scrubber, tubes and dead space in our throat and lungs etc) this gives us a fraction of 60/6000= 1% Right so in a worst case situation you'll have a fraction of 1%. At what depth does that become a problem? I'd argue that my personal limit is 30 meter on normal Air. With Argon being 2.33 times as narcotic I'd argue that my new limit becomes: 79*30/2.33 = 1017m That is such an absurd number that I don't consider Argon to be problem. So what is? Are there substances in the parts per million/billion range that have an effect? 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? __________________ Gill Envy ...Because I wasn't born with gills! ><(°>><(°>><(°>><(°>><(°>><(°>><(°>><(°>
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