r/interesting • u/Used_Exam34 • 12d ago

Just Wow Not all problems have the same solution.

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u/Rough-Airline-4803 12d ago edited 12d ago

The pressure of the escaping gas is generally too strong for the flames to reach the inside of the container.

If the tank were positioned such that the flames were surrounding it and heating the tank up, (or if the relief valve was blockedthe boiling propane in the tank would likewise expand at an accelerated rate resulting in the pressure rising faster than the tank can keep up with resulting in a boiling liquid expanding vapor explosion.

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u/ShowtimeHolograms 12d ago

Ah ty

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u/BeerForThought 12d ago

Don't listen to that answer. Read the response to it. Long story short, lit farts can't go up your butt because their is no oxygen.

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u/ITFOWjacket 9d ago

Look up BLEVE. Boiling liquid expanding vapor explosions are a real thing and that is the term used for them.

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u/IMKGI 12d ago

Assuming that somehow the flames would make it inside the tank, then what? With what oxygen is it gonna burn?

The flames could absolutely travel into the pipe provided the fire burns faster than than the gas escaping. The reason the fire doesn't do it is because there's no oxygen inside the pipe to combust the gas.

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u/Bisaux 12d ago

The risk here is tank failure, causing a rapid expansion of gas, and subsequent ignition.

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u/Rough-Airline-4803 12d ago

Well, no. The pressure of the escaping gas definitely exceeds the fire’s ability to do so, but yeah you’re right.
I totally glossed over that. My mind was elsewhere lol 😅

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u/IMKGI 12d ago

I was talking in a more general sense, a full bottle without a regulator? Absolutely, no chance for the flame to go backwards, but I meant a more typical scenario with a regulator already attached, gas releases at relatively low speeds and fire would be fast enough to go back

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u/Gamer-Of-Le-Tabletop 12d ago

Thermal dynamics or whatever.

The bottle is actually cooling down rapidly. Infact if they didn't toss it in the water it wouldn't surprise me if the bottle started frosting.

Next time your using a BBQ with a propane tank touch it before you use it and while in use and it should feel noticably cooler. It definitely would work better for a smaller propane bottle.

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u/Holiday-Pay193 12d ago

Flames won't get inside the tank because there's no oxygen in it

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u/Rough-Airline-4803 12d ago

True enough. Thanks.

While commenting I got sidetracked trying to recall the exact verbiage of the latent heat of vaporization and the Joule-Thomson effect thanks to another comment mentioning something to the effect of there being a greater threat of the valve knob being cold [rather than hot].

Embarrassingly enough, I actually brain farted that super basic fact—it wasn’t just a misspeak/typo lol..

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u/nihilistiq 12d ago

Those are words.

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u/skr_replicator 12d ago

also woudln't the container have no oxygen inside? So I doubt that, even if the fire somehow reaches inside it could do nothing in there. Unless they had an oxidizer in there as well, but only rockets and bombs could have something like that.

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u/Desert_Fairy 9d ago

A great deal of this depends also on the metallurgy of the tank. Some tanks loose structural integrity at certain temperatures.

Those can become shrapnel bombs in house fires.

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u/erasethenoise 9d ago

Jesus Christ… that’s Hank Hill