Rebreather World - View Single Post - O2 for suit inflation on deep Rebreather cave dives

Mdemon · 6th October 2006, 18:30

If there is a fire then I agree - I don't think the results will be pretty.

As far as sparking goes - is this a red herring? The spark isn't actually anything burning, just energy. Whilst this might ignite flammable gasses, there are none present - O2 isn't. I'm not sure whether there is enough energy in a static spark to actually ignite material, even if surrounded in O2.

Would make for an interesting experiment!

Quote: (Originally Posted by Sutty)

I suspect the risk of a fire is small. HOWEVER the consequences of a fire are really serious, oxygen filled fabrics burn really well at 1bar, how fast they would burn at 15bar I can only imagine! I very much doubt that you would be able to extinguish the fire by opening the zip before you had major burns, the consequence of 60% burns on a long dive would probably be fatal before you could even get out of the cave. Burns need major amounts of fluid resuscitation due to fluid losses from weeping burns and fluid moving into swelling tissues. Body surface area minus head and hands is about 80% of total surface area. Predicted mortality of burns is age in years + surface area burnt ie 60% burns in a 30yr old=90% mortality.
The idea that a drysuit is damp seems like a good way to reduce the chances of a static electric spark, however the area around the suit feed has had very dry gas passed through it and may be effectively dried enough to be able to generate a spark.
Overall there's no way I'd risk it.

Neil

6th October 2006, 18:30	#36 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,946	Re: O2 for suit inflation on deep Rebreather cave dives If there is a fire then I agree - I don't think the results will be pretty. As far as sparking goes - is this a red herring? The spark isn't actually anything burning, just energy. Whilst this might ignite flammable gasses, there are none present - O2 isn't. I'm not sure whether there is enough energy in a static spark to actually ignite material, even if surrounded in O2. Would make for an interesting experiment! Quote: (Originally Posted by Sutty) I suspect the risk of a fire is small. HOWEVER the consequences of a fire are really serious, oxygen filled fabrics burn really well at 1bar, how fast they would burn at 15bar I can only imagine! I very much doubt that you would be able to extinguish the fire by opening the zip before you had major burns, the consequence of 60% burns on a long dive would probably be fatal before you could even get out of the cave. Burns need major amounts of fluid resuscitation due to fluid losses from weeping burns and fluid moving into swelling tissues. Body surface area minus head and hands is about 80% of total surface area. Predicted mortality of burns is age in years + surface area burnt ie 60% burns in a 30yr old=90% mortality. The idea that a drysuit is damp seems like a good way to reduce the chances of a static electric spark, however the area around the suit feed has had very dry gas passed through it and may be effectively dried enough to be able to generate a spark. Overall there's no way I'd risk it. Neil __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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