Steel cylinders can hold the same amount of air as aluminum cylinders, but with a smaller size and/or lower pressure?

[admikar]

And the explosion pressure is much higher, possibly double!

I thought you were talking about 2x service pressure and then I see this

As an engineer I was trained to use a safety factor of 3 when designing pressure vessels.
So the stress in the metal will reach the tensile strenght of the material at 232×3=696 bar. That is twice the hydro test pressure.

So, most likely, your valve would melt away anyway before we get enough heat to burst a tank?

 

[L13]

I thought you were talking about 2x service pressure and then I see this

So, most likely, your valve would melt away anyway before we get enough heat to burst a tank?

The meliting point of brass is ~1200K or more depending on alloy details, 3x service pressure is at ~900K, so:

No, the valve won't melt first, but the soft parts (seat and o-rings) will fail from heat long before a steel tank will burst.

 

[admikar]

That's what I was alluding to