Nitrox Tank

[ajduplessis]

Because O2 is such an excellent oxidant that in high enough concentrations the right fuel source can ignite at ambient temperatures. It was one of the first things I learned in my blending class.

Can you please define and back the "enough concetrations" statement.
An example would be great!!

 

[ajduplessis]

No need, that's been done by our fellow ScubaBoard posters who are much more versed in the subject than I am.
But I do appreciate the Einstein comparison, thanks.

:cool2:

I agree. This is very obvious.

 

[PfcAJ]

You're pretending that you can totally remove heat from the system. You can't. That's not reality. If you're trying to split hairs to sound smart, you're failing.

In real life, some heat DOES exist (during filling, opening the valve), and the tank really needs to be cleaned to mitigate that risk. Just get the damn tank cleaned, and be on your way.

 

[Slamfire]

However heat/pressure is being raised time and time again. The debate is around O2 and fuel only. No heat or ignition source.

I'm not sure I completely understand what you are referring to. If you are saying that O2 and fuel but no heat would not combust, you are right. At least theoretically. No heat means absolute zero temperature which is a technical impossibility. If you have ambient temperature higher than absolute zero, you have heat. If you happen to have an O2 concentration and pressure that makes a certain fuel reach an autoignition temperature that's very close to ambient temperature, well... better have the insurance papers in order.

If you are referring that in our hypothetical scenario we have an autoignition temperature above ambient and ambient will never change, then yes, you are right again. In real life, though, ambient temperature constantly changes you could have slow filled an unclean O2 cylinder in winter, stored it in your unheated garage, only to have it blow up as spring/summer arrives.

 

[boulderjohn]

I'm just going to surrender. You must be right, and I apologize for arguing.

For the benefit of the rest of the world that deals with oxygen, you should immediately inform all of the official organizations that teach oxygen handling that everything they have been teaching for so many decades is totally wrong. I am sure they will be grateful to hear that and will immediately start changing all their instructional materials.

Now we can finally end all of this needless care and work we now do to avoid flash fires and explosions.

 

[PfcAJ]

YouTube - I reject your reality and substitute my own.

 

[idocsteve]

I agree. This is very obvious.

It's also very obvious that you are entirely too dense to concede a point that is not only a very simple concept but has been explained to you several different ways by several different posters and is the reason for standards that have been in place in the Scuba diving industry for decades.

 

[boulderjohn]

standards that have been in place in the Scuba diving industry for decades.

...and people were filling O2 tanks for a long time before scuba was invented.

 

[ben_wilson3301]

Direct quote from the PADI Enriched Air Manual page 26 and 28: "1. Fire/explosion hazard. You've already learned that many substances readily burn or explode when in contact with pure oxygen or high proportions of oxygen. These substances include trace hydrocarbons (lubricants) found in normal compressed air scuba. Therefore, normal compressed air can create a hazard if it comes in contact with high oxygen concentrations. This is why blenders use oxygen compatible air for partial pressure blending. Attempting to blend enriched air without following proper filling procedures can be very hazardous. Never put pure oxygen in a standard cylinder and fill it or have it filled from a conventional scuba air fill station in an attempt to make enriched air. This practice poses a high risk of fire or explosion."

Concentrations??? Isn't 100% high enough
Fire triangle: O2 = Got it!
Fuel = A tank with silicone lubricant (hydrocarbon). Check!
Heat/Ignition Source = The heat created from the expanding aluminum. = Boom!

Why do you think the insurance is so high for any place that fills O2 tanks, and not just the scuba shops?

 

[ben_wilson3301]

Well I guess they should have said "Hopefully by now some of you have learned..."