Nitrox Only

[rjack321]

No source of ignition is necessary. These substances can self-ignite. This may be even more likely under pressure.
https://www.google.com/search?as_q=&as_epq=Petroleum+based+products%2C+oils%2C+grease+and+lotions+can+self-ignite+in+the+presence+of+&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=&as_occt=any&safe=images&tbs=&as_filetype=&as_rights=#as_qdr=all&lr=&q=can+petroleum+and+pure+oxygen+self-ignite+

you need to brush up on your fire triangle.

 

[Tigerman]

I brush up on ruining it twice a year.. The firedudes has changed the diesel barrel for a propane powered water bucket now - FANCY (and much more practical is more and more of our extinguishers are foam)

 

[Skittl1321]

You can use them for reg air fills but once you switch the tank to regular air you can't switch it back to nitrox unless its O2 cleaned. Both of my tanks had nitrox stickers on them when I bought them but I switched them over to regular air (just peeled the stickers off).

PS...The stickers are a PITA to get off if they are all scratched up.

If this is a serious concern, I'm not sure I'd trust that a used tank (it sounds like these were bought used) had been properly used by the previous owner, and would probably get them O2 cleaned before using with nitrox anyway.

 

[101recon]

Analytical Chemist, Inc. http://www.airanalysis.com/Home_Page.html specializes in the analysis of compressed gases and life support systems for Scuba Diving, Fire and EMS workers and the Military. The following is copied from this page: http://www.airanalysis.com/Oxygen_Compatible_Air.html

　
"Adding compressed air directly to pure oxygen brings the danger of fire caused by ignition of the piping which becomes fuel for the oxygen. IGNITION COMES FROM hot spots inside the piping or SCUBA flask which can be caused by particle impingement AND OXIDATIVE HEATING OF ACCUMULATED FUGITIVE OIL. Sampling, analysis and specification protocols for this differ between laboratories; the differences are significant."

"The least expensive way to prepare oxygen enriched air (i.e. Nitrox) is to add compressed air directly to a cylinder which contains pure oxygen; this is called Partial Pressure Blending. Unfortunately, partial pressure blending is potentially dangerous. A fire in pure oxygen starts with ignition by particles hitting/scraping the piping walls as they rapidly shoot through the piping OR BY SPONTANEOUS COMBUSTION OF AN ACCUMULATED OIL SPOT. Therefore, air to be mixed with pure oxygen must meet purity criteria which are more stringent than for normal SCUBA air."

　
I don't see how it gets any plainer than that guys.

 

[Tigerman]

Youre right, its pretty plain and straight forward that THERE IS A SOURCE OF IGNITION and that it does not just randomly explode because there is oxygen and fuel in the same container..

 

[101recon]

When I said no source of ignition is necessary I should have said no spark is necessary. Please forgive me.

 

[dfx]

Spontaneous combustion - Wikipedia, the free encyclopedia

Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly accelerates to high temperatures) and finally,ignition.^[1]

Stuff can spontaneously self-ignite.

 

[Tigerman]

Yeah, the diet coke can also fountain out of the bottle if someone spontaneously introduce some mentos..

 

[fbk]

Happy Thanksgiving,

Recently, I bought a couple of tanks that had stamped on the valve stem "Nitrox Only". Can anybody provide a good reason why I should only fill these tanks with Nitrox?

Debajo

There is the possibility that the valves might be of EU origin which use a slightly different (M26) DIN thread for dedicated Nitrox 1st stages. Have you tried a regular DIN first stage or is it a yoke fitting?

 

[Tigerman]

I keep hearing about these socalled european nitrox valves - Ive NEVER seen one though..