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|10-12-2006, 03:51 PM||#21 (permalink)|
Guys, this is the reason everyone thinks you shouldn't do it (I think)
"The main reason we do not recommend people put CO2 into fiber and Carbon Fiber Series bottles is mainly because of hydro testing. Its not so much that it is not safe, it is more because the bottles chance of passing hydro testing in 3 years is drastically less. The problem is that with CO2 is that it causes the aluminum shell to shrink ever so slightly. After the shell starts to shrink it actually pulls the away from the fiber or Carbon Fiber wrap. Eventually it causes the bottle structure to weaken. Which can (and does) decrease the chances of it passing the hydro test. When a bottle fails a hydro test they drill a hole in it so it will not be able to hold air. "
However, none of the bottle manufactures will back that up. In fact, I believe manike spoke to carleton & luxifer and they said it was BS; but I have no actual proof of that.
|10-14-2006, 12:33 AM||#22 (permalink)|
Needs new knees
Join Date: Apr 2006
Location: St. Louis
As hot as some tanks get when being filled with HPA and then cooling down, you would see the tank delaminating before it would happen using CO2. Theres more temp differential using HPA than with CO2. If you dont feel comfortable using CO2 in a fiberwrapped tank, then dont, but it is safe.
There seems to be a "Fear" of HPA tanks that is wholly unfounded. Now it is good for beginers to be somewhat timid about HPA, but its getting almost to the silly stage. A tank will NOT "Explode" by pressure alone. If you introduce oil into the tank, then fill it up, then yes it can and has happened. One reason your now starting to see it happening, is how fast they have been filling tanks. 4 years ago there werent many fill stations that could slam 4500psi of air into a tank that quickly, but everyone wants their air "Right Now". At a Chicago NPPL, I used an infrared handheld thermometer, to measure the temp of tanks immediatley after being filled. Guess how high some of them were? Over 120-130 degrees at times......
I dont remember what the DOT standard is for temps, but it is lower than 120*. When air fills were done by boosters, they filled it much slower, and safer.
So, when using CO2 in a fiber wrapped tank, it is perfectly safe, as long as you mind the STANDARD CO2 tank proceedures. The Co2 isnt going to go over the rated pressure, unless you use artificial means. Now if you happen to overfill it, and happen to park it in the sun, then it might blow the burst disc, like any other CO2 tank, aluminum or otherwise. If your field wont fill it, then I wouldnt trust them to fill an HPA tank properly. They are clearly untrained. How many fields actually check every tank for hydro dates BEFORE they fill them, everyday?
Also, tanks dont catastrophicly explode like you would think. If the tank does fail, it would be a small hole, not the whole tank shredding. Its becoming an urban legend! The only tanks that have actually "Exploded" where done on purpose to see how high they would go. And it took over 10,000psi if I recall correctly, to shred the tank.
Wow, what got into me????..........
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