CO2 pressure bottle, Stainless steel Vs. aluminium alloy, which is safer ?

[rogerfans]

What's your opinion on this topic?

I think in the limit condition, if the over pressure, the decompression valve is invaild, bottle body occurs explosion. aluminium might be safer than stainless steel bottle. beacuse aluminium just break from the body, the stainless steel will be break into pieces...

[Darkblade48]

All of this would be supposition at best. I have never seen a cylinder (over)filled to the point where the pressure release valve failed and caused a cylinder explosion.

The pressure release valve will always give first, since that is what it was designed to do.

[Matt F.]

Yes, I agree with Darkblade48. I don't think this is an issue. No professional gas company will overfill a CO2 tank. They are hydro-tested and stamped every 5 years by law here in the USA, there is a pressure release valve, and they are engineered to store pressurized gas. I've seen plenty of these tanks (steel and aluminum) used and abused for many years. they will last forever. Coke and Pepsi distribute aluminum tanks, fwiw.

One thing to consider is the fact that steel tanks can/do rust internally. If you aren't using a CGA filter, you might get rust particles in your regulator which can cause leak or mechanical failure. with aluminum tanks, you don't have to worry about this.

[HD Blazingwolf]

keep in mind also that most service pressure's for even aluminum tanks is 1800 psi with a max pressure of 3000 psi. the relief valve is around 1800-2200 psi. so there is a margin for error there. especially considering that most tanks in the hot sun will only get to about 1300-1400 psi which isn't even their service pressure