Oxygen fire. Please read

[GLOC]

Oxygen fire. Please read

More here on the subject of spontaneous combustion

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120003032_2012002559.pdf

Regards

[weazelz]

I give up

I will maintain that for materials used in mainstream diving equipment - ie brass & stainless steel - they do not spontaneously combust - as indeed do not vaselin'd BASC 'tashes at 3ATA of O2 (I blame Chasey for that one)

honestly - regulate yourselves before someone else does [Janos bait 101]

[Major Clanger]

Oxygen fire. Please read

Iain has an interesting take on this and why black soot like particles are found in cylinders during cleaning but he's not migrated and it's over the other place. Reckons that it happens more often than we know on a micro level within our gear. Trouble is, he then goes on to sweat the detail and annoy everyone.

[GLOC]

Oxygen fire. Please read

I know brass and steel don't spontaneously combust!

If oil and grease aren't an issue with high pressure O2, then why is there all the advice about not mixing the 2? I'm not talking about just inside the diving industry.

Genuinely interested.

Regards

[GLOC]

Oxygen fire. Please read

Andy,

This is what I think happens. As you seem so knowledgeable in this area, please correct me I am wrong.

Certain base assumptions/comments:

When a substance oxidises (rust is oxidisation, but a slow pace) a chemical reaction takes place which generates heat.
For combustion to occur there needs to be heat, fuel and oxygen
For sustained combustion there needs to be significant fuel, continued O2 and sufficient heat to support the combustion

Using a pure O2 scuba diving environment, there is O2, should be no fuel (hydrocarbons) and no heat. The regulator is opened and O2 flows through the system. The gas is restricted as it moves and causes friction. In the case of a presence of an oxidising fuel (oil/grease), this oxidises and will raise the local temperature. If that temperature rises enough to allow spontaneous combustion of ANY fuels present, an ignition will occur. If there is enough fuel to continue the combustion and raise the temperature higher, other items may become fuel because their ignition temperatures have been reached.

In the case of the report above, the O2 escaping produced a situation where enough fuel (grease/oil) was being oxidised to raise the local temperature to ignite the fuel, once that happens, you have a sustainable fire.

No ignition source has been introduced and yet you have a sustainable fire because you have fuel, heat and oxygen.

Regards

[Fernando. Rueda]

Hi Guys,

Just read this and though I would let you know that my two year old inspiration Rebreather caught a light exactly the same way last 28th June 2019 whilst running the start up procedure, on opening the O2 ads I have done 100's of times, within a second it caught on fire I wasn't so lucky and sustained some burns to my left hand and face which are busy being treated specialist burn doctors.

The cause is still completely unknown we suspect maybe a ~HP hose ruptured but nothing conclusive as yet the back of the first stage blew off as well, I can categorically say that if it had been strapped toy back when opening the O2 the outcome would have been horrific

I can categorically advice NEVER to open your O2 whilst the machine is strapped to one's back

i am not very affair with these posts but would like to share some photographs and really hope we can learn something from this

[Darren A]

Hi Guys,

Just read this and though I would let you know that my two year old inspiration Rebreather caught a light exactly the same way last 28th June 2019 whilst running the start up procedure, on opening the O2 ads I have done 100's of times, within a second it caught on fire I wasn't so lucky and sustained some burns to my left hand and face which are busy being treated specialist burn doctors.

The cause is still completely unknown we suspect maybe a ~HP hose ruptured but nothing conclusive as yet the back of the first stage blew off as well, I can categorically say that if it had been strapped toy back when opening the O2 the outcome would have been horrific

I can categorically advice NEVER to open your O2 whilst the machine is strapped to one's back

i am not very affair with these posts but would like to share some photographs and really hope we can learn something from this

Blimey, I know these things try and kill you every dive, I didn’t realise they try and cremate you as well. Glad you were not hurt more badly.

No doubt AP will charge you to repair the unit.