O2 for suit inflation on deep Rebreather cave dives

decoweenie · 8th October 2006, 17:04

Quote: (Originally Posted by Mdemon)

...Mwuhahahaaaaaaaaaaaaaa!

(PS Yes, the weather is crap and there's no diving anywhere.

)

Yah, keep it up and one of these days, young man...

Barrie Law · 8th October 2006, 17:27

Quote: (Originally Posted by iain-hsm)

It would be interesting to know just how many dives you have on pure 02 suit inflation and to what depth…..and why? When Air or Nitrogen for that matter is just as “good” in molecular size.

When we test materials in oxygen under pressure to see the reaction we do the same test 20 times before increasing either the pressure or temperature or both. 1 fire in 20 tests is interesting, 3 fires in 20 and were thinking, 13 fires in 20 test time to choose another material but I never considered the luck of the Irish. How many dives was that again Barry? lol

Static discharge is the biggest risk IMHO. Remember when girls wore those fluffy nylon tops and the hairs on your arms tingled when you got a hand up. At the time I would have thought she was hot! As the video enclosed shows….. I was right.
(Yes, agreed I would have moved the car first too)

Hi Iain,

Interesting video and certainly confirms the flammability of petrol when in contact with an ignition source and that dry clothes can produce a spark.

I have done 40+ dives using Oxygen for suit inflation to depths deeper than 60 mtrs without incident. My reason for using Oxygen was to eliminate Nitrogen from my suit as I dive with Heliox and I wanted to prevent any possibility of a skin bend from Nitrogen.

After researching with a professional gas engineer and an anatomy doctor it seemed the biggest danger was post-dive when opening the suit, naked flames and sparks where the biggest concern although this was off-set somewhat by the 'Damp' condition of my under-suit post dive.

I did some testing with undergarments using static and also naked flames to gauge the possible danger before using O2 but found even mildly damp under-suit's quite difficult to ignite.

Oxygen because we metabolise it would eliminate my concerns regarding Nitrogen skin bends and subject to it's safety record reduce the need for me to carry a cylinder that whilst using Heliox I could not breath from if the need arose.

I had also noticed an increase in body temperature and comfort levels at the end of longer dives on Heliox, when the loop contained only Oxygen and this also prompted me look further at Oxygen use.

As I stated in my previous post;

"Like DRMike if there is a proven instance of diver injury due to using O2 in the DS I would like to hear about it, none exist outside of the 'pub rumour' to my knowledge.

Risk assessment and dive planning aside using O2 in your DS is probably something you do not need to be worrying about during your dive but I would not castigate those who do choose to use it accept maybe the smokers amongst us."

As with many things in diving it is a work in progress and not "Proven" or something most divers would be engaged in but I think it is useful to know that it may be considered during an emergency.
Regards

Mdemon · 8th October 2006, 20:00

Quote: (Originally Posted by iain-hsm)

It would be interesting to know just how many dives you have on pure 02 suit inflation and to what depth…..and why? When Air or Nitrogen for that matter is just as “good” in molecular size.

Lots. 3hrs+ and 130m.

No lasting ICD, "warm" molecule, allows redundancy of inflation and O2 and I have enough crap to carry without a separate tin for my DS.

RonMicjan · 8th October 2006, 23:59

Well the major problem where the sh1t is gonna hit the fan, is doing a long deep dive with O2 in the suit after a big breakfast of huevos rancheros, now you have a seriously explosive mixture of fartrox, or less commonly known as meth-ox, a known contributor to global warming, one small bit of friction, a tiny static discharge, and ka-boomie, roast diver. Im pretty sure that is the method of providing the staged explosion that was filmed in "the cave" movie. Andres Matthes was the stunt diver, and we all know where he lives, yup, mexico, look at what happened to his hair for gosh sakes.
Enough concentration of meth-ox in a divers dry suit and you could even have spontaneous diver combustion, a rare killer of deep cave diver.

Its the devils gas, whatever you call it, fartrox or meth-ox, beware of this deadly combination and stay away from the beans when using oxygen as a drysuit inflation gas...YOU HAVE BEEN WARNED!!

and now, back to our regularly scheduled thread....

iain-hsm · 9th October 2006, 16:35

Glad you liked the video I know not the same, but shows sufficient discharge energy with petrol fumes. There is another engineers classic with balloons filled with hydrogen and oxygen all packed in a large bin liner you roll the sealed bin liner with the balloons inside around the shop floor and bingo! H leaks from the balloons and the small static build up discharge is enough for the lot to go up.

This is becoming interesting, I cant work out either an unsuficiant static build up or a natural drain or both. Look up data on olefin fiber the stuff Thinsulate is made from and clearly there is a reduced static on these fibers, but the nylon cover? Also is there insufficient static discharged in the spark to start the chain reaction or kindling effect on the material?

Or is it the increase in water vapour that decreases the fire risk? I have seen videos of chamber test fires on manikin dummies in oxygen concentrations of 23 to 50% using water mist rather than water deluge I wasn’t that impressed with the mist as the dummy was still burning 30 seconds after ignition. We went for a 500 gallon water deluge within 5 seconds of activation in our chambers but are still paranoid on proper static drains. Granted it’s a different application dry not damp and huge gas flows that create the static in the first place, together with the electrical gear and shell material but we were at 3 bar ATA not 7 to 14.

But would still like to see a sample of nylon backed Thinsulate saturated with oxygen and some form of static build up to discharge. The gas burner piezo actuator is possibly much to powerful but I don’t have a figure.

The Avon dry suit example of the only diver fire I know can be put down to the wooly bear material (a pure nylon pile) inside an insulated rubber suit and smoking. Proberbly a hot ember from the ash of enough energy to start the chain reaction or kindling effect.

So my question now is what is the maximum static discharge possible in a suit and is this capable of a kindling effect in an oxygen saturated material, firstly dry then the same question with increased water vapour.
For those concerned with methane there is an old 1960s paper on oxy methane 3:1 ratio explosion experiments using massive gas ballons of 100ft plus diameter to mimic a nuclear blast (not sure if suitable on the forum)

mortenkjerulff · 9th October 2006, 17:02

Does anyone know if the ignition temperature of a material is a function of the partial pressure of oxygen surrounding the material, or if that is irrelevant?

If not, then why should we be afraid of a fire in our drysuit, when we normally do not burn holes in our clothing during diving (I know that more oxygen makes the fire more violent).

Morten

babar · 9th October 2006, 18:21

Quote: (Originally Posted by Barrie Law)

"Like DRMike if there is a proven instance of diver injury due to using O2 in the DS I would like to hear about it, none exist outside of the 'pub rumour' to my knowledge.

Risk assessment and dive planning aside using O2 in your DS is probably something you do not need to be worrying about during your dive but I would not castigate those who do choose to use it accept maybe the smokers amongst us."

As with many things in diving it is a work in progress and not "Proven" or something most divers would be engaged in but I think it is useful to know that it may be considered during an emergency.
Regards

Well, It may or may not be relevent, but there was a poster presentation at the UHMS conference last year. It reported a case of 2nd degree burns that resulted from the use of a chemical hand warmer placed down the leg of a DS. The diver was using Nitrox 36 for back gas and dry suit inflation. On descent she began to have pain in her leg, which she thought was squeeze. Inflated the suit immediately made the pain worse and she surfaced with partial thickness burns to her leg.

Not really close to the same case, but related and worth thinking about.

Mdemon · 9th October 2006, 19:06

Quote: (Originally Posted by babar)

Well, It may or may not be relevent, but there was a poster presentation at the UHMS conference last year. It reported a case of 2nd degree burns that resulted from the use of a chemical hand warmer placed down the leg of a DS. The diver was using Nitrox 36 for back gas and dry suit inflation. On descent she began to have pain in her leg, which she thought was squeeze. Inflated the suit immediately made the pain worse and she surfaced with partial thickness burns to her leg.

Not really close to the same case, but related and worth thinking about.

Chemical? Could this be the carbon handwarmer incident I was refering to? This is a carbon rod, ignited and left to smoulder in an insulated case. Fine in air, not much fun in 100% O2!

Iain, this sounds like the ideal opportunity for more experimentation!

Barrie Law · 10th October 2006, 00:33

Quote: (Originally Posted by mortenkjerulff)

Does anyone know if the ignition temperature of a material is a function of the partial pressure of oxygen surrounding the material, or if that is irrelevant?

If not, then why should we be afraid of a fire in our drysuit, when we normally do not burn holes in our clothing during diving (I know that more oxygen makes the fire more violent).

Morten

Hi Morten,

I believe it is the 100% Oxygen rather than the Bar pressure that is the concern here because although Oxygen will not Burn (*) it will cause a fire once ignited to vigorously spread within the drysuit as you mention.

The question is can a fire be started in a DS during a dive given the normally damp condition of the undersuit and is the material used in the undersuit capable of producing enough static to ignite the undersuit even if bone-dry?

I suspect Mdemon or Iain-hsm will have some results on that but the best I could do even with a naked flame was to melt a bit of the material from the undersuit.

(*) There was a fact regarding Oxygen burning that escapes me but it was not relevant to using it in a DS.

Regards

Mdemon · 10th October 2006, 07:07

How to produce a static spark?

Was thinking of a balloon with a duster inside a bin liner of O2 - rub balloon and see what sparks do. Looking on the bright side, if it blows my hands off at least it will stop me from picking my nose.

Any other ideas?

8th October 2006, 17:04	#51 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by Mdemon) ...Mwuhahahaaaaaaaaaaaaaa! (PS Yes, the weather is crap and there's no diving anywhere. ) Yah, keep it up and one of these days, young man... __________________ "...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..." - Rebreather World PM
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8th October 2006, 17:27	#52 (permalink)
Barrie Law RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jun 2005 Location: Ireland Posts: 459	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by iain-hsm) It would be interesting to know just how many dives you have on pure 02 suit inflation and to what depth…..and why? When Air or Nitrogen for that matter is just as “good” in molecular size. When we test materials in oxygen under pressure to see the reaction we do the same test 20 times before increasing either the pressure or temperature or both. 1 fire in 20 tests is interesting, 3 fires in 20 and were thinking, 13 fires in 20 test time to choose another material but I never considered the luck of the Irish. How many dives was that again Barry? lol Static discharge is the biggest risk IMHO. Remember when girls wore those fluffy nylon tops and the hairs on your arms tingled when you got a hand up. At the time I would have thought she was hot! As the video enclosed shows….. I was right. (Yes, agreed I would have moved the car first too) Hi Iain, Interesting video and certainly confirms the flammability of petrol when in contact with an ignition source and that dry clothes can produce a spark. I have done 40+ dives using Oxygen for suit inflation to depths deeper than 60 mtrs without incident. My reason for using Oxygen was to eliminate Nitrogen from my suit as I dive with Heliox and I wanted to prevent any possibility of a skin bend from Nitrogen. After researching with a professional gas engineer and an anatomy doctor it seemed the biggest danger was post-dive when opening the suit, naked flames and sparks where the biggest concern although this was off-set somewhat by the 'Damp' condition of my under-suit post dive. I did some testing with undergarments using static and also naked flames to gauge the possible danger before using O2 but found even mildly damp under-suit's quite difficult to ignite. Oxygen because we metabolise it would eliminate my concerns regarding Nitrogen skin bends and subject to it's safety record reduce the need for me to carry a cylinder that whilst using Heliox I could not breath from if the need arose. I had also noticed an increase in body temperature and comfort levels at the end of longer dives on Heliox, when the loop contained only Oxygen and this also prompted me look further at Oxygen use. As I stated in my previous post; "Like DRMike if there is a proven instance of diver injury due to using O2 in the DS I would like to hear about it, none exist outside of the 'pub rumour' to my knowledge. Risk assessment and dive planning aside using O2 in your DS is probably something you do not need to be worrying about during your dive but I would not castigate those who do choose to use it accept maybe the smokers amongst us." As with many things in diving it is a work in progress and not "Proven" or something most divers would be engaged in but I think it is useful to know that it may be considered during an emergency. Regards __________________ Barrie Law Rebreather World Store Supplying the Rebreather World Tel:US +19548403892 Fax:US+19543333792 Tel:EU+442071930496 Fax:EU+442077606344 Mobile+353876880628 Skype:barrielaw Email: barrie@rebreatherworldstore.com
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8th October 2006, 20:00	#53 (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: 1,927	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by iain-hsm) It would be interesting to know just how many dives you have on pure 02 suit inflation and to what depth…..and why? When Air or Nitrogen for that matter is just as “good” in molecular size. Lots. 3hrs+ and 130m. No lasting ICD, "warm" molecule, allows redundancy of inflation and O2 and I have enough crap to carry without a separate tin for my DS. __________________ 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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8th October 2006, 23:59	#54 (permalink)
RonMicjan Cap Ron scourge of the NW Current Rebreather/s: Megalodon Dolphin Home Build Other Rebreather/s: Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Cape Disapointment, The Graveyard of the Pacific Posts: 1,100	Re: O2 for suit inflation on deep Rebreather cave dives Well the major problem where the sh1t is gonna hit the fan, is doing a long deep dive with O2 in the suit after a big breakfast of huevos rancheros, now you have a seriously explosive mixture of fartrox, or less commonly known as meth-ox, a known contributor to global warming, one small bit of friction, a tiny static discharge, and ka-boomie, roast diver. Im pretty sure that is the method of providing the staged explosion that was filmed in "the cave" movie. Andres Matthes was the stunt diver, and we all know where he lives, yup, mexico, look at what happened to his hair for gosh sakes. Enough concentration of meth-ox in a divers dry suit and you could even have spontaneous diver combustion, a rare killer of deep cave diver. Its the devils gas, whatever you call it, fartrox or meth-ox, beware of this deadly combination and stay away from the beans when using oxygen as a drysuit inflation gas...YOU HAVE BEEN WARNED!! and now, back to our regularly scheduled thread.... __________________ Marine rescue, towing and salvage. Interfering with natural selection since 1983. www.tmishop.com Diving bits etc. www.seatowpdx.com The Summer Job
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9th October 2006, 16:35	#55 (permalink)
iain-hsm Custom Title Allowed! Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Other CCR Other SCR Join Date: Mar 2005 Location: Loughborough England uk Posts: 347	Re: O2 for suit inflation on deep Rebreather cave dives Glad you liked the video I know not the same, but shows sufficient discharge energy with petrol fumes. There is another engineers classic with balloons filled with hydrogen and oxygen all packed in a large bin liner you roll the sealed bin liner with the balloons inside around the shop floor and bingo! H leaks from the balloons and the small static build up discharge is enough for the lot to go up. This is becoming interesting, I cant work out either an unsuficiant static build up or a natural drain or both. Look up data on olefin fiber the stuff Thinsulate is made from and clearly there is a reduced static on these fibers, but the nylon cover? Also is there insufficient static discharged in the spark to start the chain reaction or kindling effect on the material? Or is it the increase in water vapour that decreases the fire risk? I have seen videos of chamber test fires on manikin dummies in oxygen concentrations of 23 to 50% using water mist rather than water deluge I wasn’t that impressed with the mist as the dummy was still burning 30 seconds after ignition. We went for a 500 gallon water deluge within 5 seconds of activation in our chambers but are still paranoid on proper static drains. Granted it’s a different application dry not damp and huge gas flows that create the static in the first place, together with the electrical gear and shell material but we were at 3 bar ATA not 7 to 14. But would still like to see a sample of nylon backed Thinsulate saturated with oxygen and some form of static build up to discharge. The gas burner piezo actuator is possibly much to powerful but I don’t have a figure. The Avon dry suit example of the only diver fire I know can be put down to the wooly bear material (a pure nylon pile) inside an insulated rubber suit and smoking. Proberbly a hot ember from the ash of enough energy to start the chain reaction or kindling effect. So my question now is what is the maximum static discharge possible in a suit and is this capable of a kindling effect in an oxygen saturated material, firstly dry then the same question with increased water vapour. For those concerned with methane there is an old 1960s paper on oxy methane 3:1 ratio explosion experiments using massive gas ballons of 100ft plus diameter to mimic a nuclear blast (not sure if suitable on the forum)
(Offline)

9th October 2006, 17:02	#56 (permalink)
mortenkjerulff Customise Me! Current Rebreather/s: Megalodon Other Rebreather/s: Not Bought Yet Join Date: Mar 2005 Location: Denmark Posts: 143	Re: O2 for suit inflation on deep Rebreather cave dives Does anyone know if the ignition temperature of a material is a function of the partial pressure of oxygen surrounding the material, or if that is irrelevant? If not, then why should we be afraid of a fire in our drysuit, when we normally do not burn holes in our clothing during diving (I know that more oxygen makes the fire more violent). Morten
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9th October 2006, 18:21	#57 (permalink)
babar Curmudgeon Current Rebreather/s: Evolution Sport Kiss Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Other CCR Join Date: Apr 2005 Location: Southern California Posts: 417	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by Barrie Law) "Like DRMike if there is a proven instance of diver injury due to using O2 in the DS I would like to hear about it, none exist outside of the 'pub rumour' to my knowledge. Risk assessment and dive planning aside using O2 in your DS is probably something you do not need to be worrying about during your dive but I would not castigate those who do choose to use it accept maybe the smokers amongst us." As with many things in diving it is a work in progress and not "Proven" or something most divers would be engaged in but I think it is useful to know that it may be considered during an emergency. Regards Well, It may or may not be relevent, but there was a poster presentation at the UHMS conference last year. It reported a case of 2nd degree burns that resulted from the use of a chemical hand warmer placed down the leg of a DS. The diver was using Nitrox 36 for back gas and dry suit inflation. On descent she began to have pain in her leg, which she thought was squeeze. Inflated the suit immediately made the pain worse and she surfaced with partial thickness burns to her leg. Not really close to the same case, but related and worth thinking about. __________________ Babar Evolution Plus Sport kiss
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9th October 2006, 19:06	#58 (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: 1,927	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by babar) Well, It may or may not be relevent, but there was a poster presentation at the UHMS conference last year. It reported a case of 2nd degree burns that resulted from the use of a chemical hand warmer placed down the leg of a DS. The diver was using Nitrox 36 for back gas and dry suit inflation. On descent she began to have pain in her leg, which she thought was squeeze. Inflated the suit immediately made the pain worse and she surfaced with partial thickness burns to her leg. Not really close to the same case, but related and worth thinking about. Chemical? Could this be the carbon handwarmer incident I was refering to? This is a carbon rod, ignited and left to smoulder in an insulated case. Fine in air, not much fun in 100% O2! Iain, this sounds like the ideal opportunity for more experimentation! __________________ 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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10th October 2006, 00:33	#59 (permalink)
Barrie Law RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jun 2005 Location: Ireland Posts: 459	Re: O2 for suit inflation on deep Rebreather cave dives Quote: (Originally Posted by mortenkjerulff) Does anyone know if the ignition temperature of a material is a function of the partial pressure of oxygen surrounding the material, or if that is irrelevant? If not, then why should we be afraid of a fire in our drysuit, when we normally do not burn holes in our clothing during diving (I know that more oxygen makes the fire more violent). Morten Hi Morten, I believe it is the 100% Oxygen rather than the Bar pressure that is the concern here because although Oxygen will not Burn () it will cause a fire once ignited to vigorously spread within the drysuit as you mention. The question is can a fire be started in a DS during a dive given the normally damp condition of the undersuit and is the material used in the undersuit capable of producing enough static to ignite the undersuit even if bone-dry? I suspect Mdemon or Iain-hsm will have some results on that but the best I could do even with a naked flame was to melt a bit of the material from the undersuit. () There was a fact regarding Oxygen burning that escapes me but it was not relevant to using it in a DS. Regards __________________ Barrie Law Rebreather World Store Supplying the Rebreather World Tel:US +19548403892 Fax:US+19543333792 Tel:EU+442071930496 Fax:EU+442077606344 Mobile+353876880628 Skype:barrielaw Email: barrie@rebreatherworldstore.com
(Offline)

10th October 2006, 07:07	#60 (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: 1,927	Re: O2 for suit inflation on deep Rebreather cave dives How to produce a static spark? Was thinking of a balloon with a duster inside a bin liner of O2 - rub balloon and see what sparks do. Looking on the bright side, if it blows my hands off at least it will stop me from picking my nose. Any other ideas? __________________ 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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