Carbon fiber tank failure.

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I was reading some of the info everyone has been nice enough to provide and I am a little confused on the life extension guide lines in regard to the five year retest, if I am reading it correctly instead of a hydro retest every five years the program calls for Modal acoustic tests every five years. Has anybody asked the sellers of the life extended tanks if that is the case?

Thanks again,

Jim 
 
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Pyramyd Air is the US vendor for civilian tanks being recertified by Modal Acoustics. Not sure but somewhere I heard the tests are a touch more expensive than standard hydro tests. My last tank cost $30 if I remember correctly for the hydro. I ran the numbers and there's no real advantage to the extended life tanks at this point. That may change over time, but for now, cost per year of service is about the same as buying a new tank and using the cheaper hydro test.

As for why the US DOT only allows a 15 year life span, I really don't know.

Oh, and as for failures, the examples I've seen are mostly paintball tanks. Airgunners tend to baby their tanks because we need them so much. Paintball players tend to be pretty tough on tanks, and can easily damage the epoxy coating, and compromise the integrity of the tank. The tanks are tough, but not indestructible. I have seen a video of a paintball player breaking the tank at the neck and watched it fly across the arena. Nothing to be trifled with.


 
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I would like to see an actual test of tanks failing under extreme pressure. I once visited a factory that made water well system pressure tanks. They pumped water pressure into the tanks until they failed. The steel tanks failed and was kind of violent at somewhere well below 600 psi( can't remember exact). However the fiber tanks went to just over 600 & did not explode just kind of unwound. I know there is no comparison to PCP tanks, but would like to see this same type test. 
 
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In order to throw a little context into the "sensationalized" failure in the video above, below is the "real" story of what was being recorded... Notice that the tank was INTENTIONALLY damaged by notching the composite overwrap by 50%. And even then, it didn't fail until almost 13,000 psi! If this doesn't show you just how tough these tanks really are, I don't know what else to say...

{In this video we explain the use of Modal Acoustic Emission(MAE) testing and its application to a Self Contained Breathing Apparatus (SCBA) cylinders. This specific video is regarding a SCBA that we intentionally notched the composite overwrap by 50%. Even with such a severe notch the SCBA nearly makes test pressure. This goes to show how overdesigned and safe these SCBA vessels are. Yes, the beginning is a bit dry as the MAE test procedure is explained. However you are rewarded at the end as we take this SCBA to failure.}
 
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Did the neck of the bottle break or did the regulator snap? I have been playing paintball for 20 years and have never seen or heard of a fiber wrapped bottle exploding. I am not saying it didn't happen but if so, it is very rare. Some of the cheaper manufacturers use brass regulators and they are prone to snapping when you try to remove them to be re-hydro'd.

I have also been to many fields that do not even check the hydro date before allowing people to fill their air bottles. 

They outer gel coat cracking is pretty common on Ninja tanks which are made by the Gayston Corp. They say it doesn't affect the integrity of the tank but I had an air bottle that had the gel coat cracked. I took the bottle back to Gayston and they sanded off the gel coat and re applied a new gel coat but when I went to have the bottle re hydro'd afterwards the tank failed hydro. IMO the gel coat cracking is an issue of how fast they fill the air bottles at paintball fields. They will fill an empty air bottle from 0 psi to 4500 psi in less than 3 seconds and those air bottles get really hot. 


 
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Yeah, I'm really going to start worrying about my carbon fiber tanks the next time I gouge the carbon fiber layer half way through the thickness, and then pressurize it to 13,000 psi...

;)

You only fill yours to 13 Grand? Something wrong with your compressor? ( trying to be funny , of course)

On a serious note, I am actually happy to see how much a damaged one can take, helps us all appreciate the safety factor.
Click to expand...


 
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The place I have my tank filled has one cut in half but not sure the brand of tank.



1541704334_6029660795be48a8ec30894.60627765_128.jpg

 
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