O2 on general rigs

[boogeywoogey]

Hello clique,

I was wondering how much O2 you would be prepared/have put through your first stgae safely and regularly.

Of course, manufacturers stress a max 40% but I am sure, like the sell by dates on Christmas cards it means little...OR does it???

Thank you

boogey

 

[karstdvr]

Maybe I'm an accident waiting to happen,but I've only ever owned 1 oxygen cleaned regulator,and I sold that because it was like sucking a bowling ball through a straw. I've used Mk2/R190s as my oxygen regulator for 7 years-new out of the box without cleaning. I've made approx 800 deco dives on oxygen without a problem,I'm just very careful when it comes to cracking the valve,plus I keep my valves O2 compatible.

 

[padiscubapro]

Maybe I'm an accident waiting to happen,but I've only ever owned 1 oxygen cleaned regulator,and I sold that because it was like sucking a bowling ball through a straw. I've used Mk2/R190s as my oxygen regulator for 7 years-new out of the box without cleaning. I've made approx 800 deco dives on oxygen without a problem,I'm just very careful when it comes to cracking the valve,plus I keep my valves O2 compatible.

all scubapros nowadays comeout of the box using oxygen compatible components and lubricants, but they dont guarantee that it meets oxygen service conditions.. chances are if you keep the reg from getting contaminents and you aways pressureize the system slowly you'll be ok..
but there is always that one chance... and oxygen firers happen fast, they are generally over before you even realize an ignition occurred..

 

[StSomewhere]

Technically, oxygen itself doesn't burn. What it actually does is to lower the temperature at which other materials burn. At higher O2 percentages, even stuff you wouldn't normally think of as being flammible will burn -- esp. when ignited from trace impurities (think hydrocarbons like you'd find in any grease or oil). Now put that O2 under pressure and you can burn almost anything. A fire fed by 50% O2 under pressure is indistinguisable from a fire fed by 100% O2, and is about as extinguishable. Be careful out there people. :11:

 

[karstdvr]

. chances are if you keep the reg from getting contaminents and you aways pressureize the system slowly you'll be ok..
..

I agree. Most oxygen fires I have seen have initiated in a valve due to abdiatic reasons. I keep the valve clean to oxygen specs. When I first started cave diving a haskel was unheard of,so we all used steel 72s because getting high pressures was unheard of-lucky if you could get 2000psi. Now most people use AL40s and want 3000psi and higher,I've seen more oxygen related incidents. I am always very careful when it comes to cracking the valve. Personally I've taken all my Al40s out of oxygen use,and now use steel 46s at lower pressure for oxygen.

 

[GDI]

karstdvr has what I call the ideal size cylinder for O2 deco use the steel Lp 45. The size is plenty for deco and the working psi gives you a better chance to get a full O2 cylinder. I do have a Al 30 but I seldom use that for pure O2 (85% or higher) I may from time to time use it for mixes like 60 or 70%. In any case always fill the O2 to a lp and at a slow rate using O2 compatable materials and lube

 

[karstdvr]

karstdvr has what I call the ideal size cylinder for O2 deco use the steel Lp 45. The size is plenty for deco and the working psi gives you a better chance to get a full O2 cylinder. I do have a Al 30 but I seldom use that for pure O2 (85% or higher) I may from time to time use it for mixes like 60 or 70%. In any case always fill the O2 to a lp and at a slow rate using O2 compatable materials and lube

Good advice on filling tanks slow. A smaller vessel needs a slower fill rate

I have shifted my al40s to 50/50 and one for 34% when I do a Diepolder.

I even keep a st72 with oxygen for old time sakes

 

[Rick Murchison]

Technically, oxygen itself doesn't burn.

I love this popular statement. If you define "burning" as "combining with oxygen and giving off a flame and heat" then it's true - oxygen doesn't burn - it causes other things to burn.
But you could define burning as "combining with methane and giving off a flame and heat" and say "technically, methane doesn't burn" just as well.
Let there be no doubt, whether you technically call what oxygen does "burning" or not, it is the essential ingredient is the fires that are liable to roast your tail and ruin your day.
I prefer to say it burns easily, readily and hot - like crazy.
Rick

 

[MikeFerrara]

I love this popular statement. If you define "burning" as "combining with oxygen and giving off a flame and heat" then it's true - oxygen doesn't burn - it causes other things to burn.
But you could define burning as "combining with methane and giving off a flame and heat" and say "technically, methane doesn't burn" just as well.
Let there be no doubt, whether you technically call what oxygen does "burning" or not, it is the essential ingredient is the fires that are liable to roast your tail and ruin your day.
I prefer to say it burns easily, readily and hot - like crazy.
Rick

I think the correct description would be that the O2 isn't the fuel part of the "fire triangle" (fuel, heat and oxidizer).

 

[StSomewhere]

Thanks Mike, that was the point I was trying to make.

As long as you manage the other issues (specifically the fuel) O2 can be safe, otherwise it is dangerous as all h3ll.