300 Bar/4500 PSI bottle faliure tests
Saw this on youtube and thought it was pretty interesting
These guys are pretty brave as well
http://www.youtube.com/watch?v=tyINNUaXa8Q
Dave
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Dave
I don’t have any experience with hydro testing air tanks, but my understanding has always been that you are correct in thinking that the pressure is the same- air or water. And that is exactly why they fill them with water. A catastrophic failure of an 80 cu ft tank at ~4000psi is much safer when the tank is mostly full of water. You then have a minimal amount of air in the tank to expand upon failure vs having the tank full of air, failing, and having what could be a rocket blasting around the room.
Like I said, this is just my understanding and really its just an assumption I made.
–Dan
…..should have added that he managed to cross thread the brass valve fitting it was one of the older 1/4″ threaded steel tanks as well…so no the water wasnt what actually cause the cylinder to fail..I was just giving an example about air pressure and what it can do in a tank at higher than its stamped fill pressure when it lets go…
Im not doubting you in any way but I don’t see how not filling the cylinder with water would cause the diving bottle to fail. It would be the same stress if it was water pressure or air pressure. Just curious
Dave
Actually these guys are pretty stupid…I’ve seen a 3000psi 72cf tank that went through a wall through a fire truck and then mushroomed up against a bank safe wall because the dive shop had caught on fire and blew the valve out of the top of the tank (I’m still curious as to how much presure built up in the cylinder to do that) ……Also when i was in the divign industry we used to perfrom hydrostatic test of scuba cylinders…well one day one of the testers forgot to place water inside the cylinder being tested…it blew the top of the testing unit through the roof of the shop out into the parking lot and managed to push the tank cylinder through the bottom of the testing machine and into the high pressure concrete below… :shock:..Yeah he was a dumba$$ and deaf for a couple of days on top of it.
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I read where they get pressurized to 5/3 of the pressure stamped on the tank. For AF tanks that would be 5,000 PSI. They submerge the tank in water and do not allow air inside the bottle. Water doesn’t compress and has low kinetic energy when put under pressure. If the tank fails, very little water is released.
A freshly hydro-ed tank should survive another five years of appropriate use providing no dents, scratches, etc. occur.