It can happen but the tanks are designed usually to go it a fire on the back of someone so it is a what if and if you worry about what if scenarios all the time you would be scared of everything
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HPA Tank Failure - Should I Be Concerned? What Happens When A SCBA or SCUBA Tank Fails? What Happens When A Valve Fails? (VIDEOS)
- Thread starter Ezana4CE
- Start date
Absolutely right. If used in fire fighting and are safe, airgun use will never see service like that, unless you’re stupid.
Many years ago Ann Landers had an advice column. One time she had somebody that was afraid of everything. I don’t remember the exact words and didn’t find it on google, but it went something like…
Don’t walk you might trip, don’t run you might fall, don’t sleep you might not wake up, don’t eat you might choke, don’t swim you might drown.
Get the idea? There are no guarantees in life. Is there that SCBA out there that might blow up in your face as you’re filling it? Maybe. Unlikely? Absolutely.
If that’s your fear, take up knitting. No wait, you might jam a knitting needle in your eye.
When I was learning to skydive, on my fifth or sixth jump it was just me and the pilot in a Cessna. We were flying at the moment in heavy clouds. The pilot yells to me “Watch for airplanes”. I could see the propeller, that was all. I would have seen the oncoming plane when it contacted ours. My instructors favorite saying was “You pays your money and you takes your chances”.
I did a boat load of extreme sport stuff and survived quite well. You educate yourself and make informed, hopefully wise decisions, or you just read about other peoples adventures.
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I do not worry about stuff i cannot control . In this case i just do not over fill anything and also i under fill by about 3 or 5 % .
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Not trying to be a dick, not sure I understand how 135-225psi lower pressure makes it safer.
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Fantastic read from the Navy study!
A few excerpts:
The Navy has operated SCBA GFRP and CFRP cylinders in shipboard firefighting applications for more than 16 years. Navy SCBA cylinders are among the safest and most reliable equip- ment in Navy inventory. The Navy has accumulated more than 400,000 pressurized operating years of experience with pressurized SCBA cylinders and has not experienced a single failure related to cylinder strength or integrity.
• The Navy has a robust visual inspection program. Cylinders are given a visual inspection after routine use, prior to filling, and on a monthly basis by ship firefighting-equipment maintenance personnel. Additional visual inspections are conducted by ship’s force (crew) at six-month intervals. Cylinders are also inspected at the appropriate three- or five-year test interval by
SCBA Cylinder Life-Extension Study, Final Report (August 2012) 2-1
certified testers prior to hydrostatic testing. About half of all visual inspection failures observed are due to wear or damage experienced from exposure to knocks and abrasion during frequent firefighting drills on Navy ships. The other major category of visual inspection failures consists of those induced by hydrostatic testing—including cylinder stem thread galling due to improper removal and reinstallation of the cylinder valve fitting, and to interior cylinder surface contami- nation or corrosion caused by improper drying of the cylinders after hydrostatic testing. Hydrostatic testing of the cylinders is accomplished by removing the valve from the cylinder, threading on a test connection, filling the cylinder with water, pressurizing the cylinder to five- thirds (5/3) of service pressure, and measuring cylinder expansion. Based on findings regarding testing-induced failures and the high hydrostatic testing false-positive rate, it is likely that more cylinders are damaged by the hydrostatic testing process than by service handling and usage.
The predominant failure mode associated with cylinder damage observed during the study was cylinder liner leakage vice bursting at near operational pressure. The liner leakage failure mode is not a safety concern (as defined by MIL-STD-3034) since leakage presents no immediate hazard, as the working gas for cylinders is breathing air and the failure is evident to the operator. This predominant failure mode confirms a fail-safe leak before burst behavior for Navy cylinders during worst-case conditions observed during normal service life.
^^^Can someone explain this more clearly, are they saying it won’t burst even if the liner wears away because it will fail in some other manner that isn’t ‘explosive’? Or are they saying it can burst but it’s not a flammable/poisonous/oxidizing/acidic/etc gas?
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I think part of the confusion in that paragraph is from the word "vice" in the first sentence - it makes no sense there, and I think is a word error; the only thing in that context that makes sense to me is "versus", and I think it ties in with how I read the whole thing.
If visual inspection shows no damage to the epoxy or fiber wrap, then there is zero chance of a tank "bursting" at operational pressures. The only possible failure mode is liner leakage, and that probably requires corrosion inside (most likely from a hydrostatic test, per the earlier text). When that happens, there is no hazard as the tank contains only air and the operator will know that it is happening. Personally, I would not want that to happen while I was fighting a fire, but I guess they mean that the operator would know it and could leave the fire to get a new tank.
This all indicates what I have felt for a long time - get a new or well cared for tank, don't ever let condensed water end up in it, and it will do well for you pretty much regardless of age, especially without hydrotesting, which can only be done if we fill them ourselves (although occasional internal visual testing would not hurt).
If visual inspection shows no damage to the epoxy or fiber wrap, then there is zero chance of a tank "bursting" at operational pressures. The only possible failure mode is liner leakage, and that probably requires corrosion inside (most likely from a hydrostatic test, per the earlier text). When that happens, there is no hazard as the tank contains only air and the operator will know that it is happening. Personally, I would not want that to happen while I was fighting a fire, but I guess they mean that the operator would know it and could leave the fire to get a new tank.
This all indicates what I have felt for a long time - get a new or well cared for tank, don't ever let condensed water end up in it, and it will do well for you pretty much regardless of age, especially without hydrotesting, which can only be done if we fill them ourselves (although occasional internal visual testing would not hurt).
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There is a very consistent theme when it comes to any of these tanks "blowing up." It only seems to happen when someone forces it to, or if the tank experiences some sort of catastrophic external conditions.
People get so wrapped up in the false notion that these tanks are basically just bombs waiting to explode. History and scientific testing has repeatedly proven that is simply not the case. Yet people still fear them.
There was a video years ago where a man was heavily preaching about the imminent dangers of SCBAs. He chose to demonstrate how dangerous they were by shooting it with a firearm in order to make it blow up, which it essentially did. The only thing dangerous there was between that man's ears.
People get so wrapped up in the false notion that these tanks are basically just bombs waiting to explode. History and scientific testing has repeatedly proven that is simply not the case. Yet people still fear them.
There was a video years ago where a man was heavily preaching about the imminent dangers of SCBAs. He chose to demonstrate how dangerous they were by shooting it with a firearm in order to make it blow up, which it essentially did. The only thing dangerous there was between that man's ears.
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@AlanMcD Adyer giving it more thought, they repeatedly state that the aluminum liner doesn’t provide any structural integrity and exists solely to prevent escaping gas. So I think maybe they’re saying the tanks fail in a manner where even if the liner corroded there’d be a crack and the tank wouldn’t pressurize at all or that even if the liner corrodes the CF wouldn’t and would continue to hold pressure…?
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The paragraph makes more sense if you replace "vice" with versus. I am pretty sure it says in other places no Navy tank has failed catastrophically. None have "blown up". I think SCBA tanks are safer for our application than SCUBA for several reasons due to the different construction. There seems to be a lot of margin in the carbon fiber wrap. One of the videos showed failure at 12,000 psi when half the carbon fiber was missing. How would you ever get to 12,000 psi? Who would use a tank with half the carbon fiber missing? The aluminum liner will fail if it is not supported by the carbon fiber and could fail from corrosion. But if the liner fails and the carbon fiber is intact, the tank will leak but there is no risk of it "blowing up". The carbon fiber overwrap is not leak tight but it will withstand even an overpressure. Remember, the hydro tests expansion at overpressure, the tank does not "explode".
SCUBA tanks are designed for lower pressure so our compressors could fill them up closer to their limits and their typically metal construction does not seem to provide the considerable margin of the carbon fiber. But treated appropriately I am sure SCUBA tanks are safe to use.
SCUBA tanks are designed for lower pressure so our compressors could fill them up closer to their limits and their typically metal construction does not seem to provide the considerable margin of the carbon fiber. But treated appropriately I am sure SCUBA tanks are safe to use.
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I read somewhere recently that the US Navy has 40,000 SCBA’s in their active inventory. I’m thinkin’ SCBA’s are safe.
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ALL my tanks, several including my PPCs, has the letters DOT stamped on them. The cost of some of the oversea tanks are very attractive without the DOT stamps. Since the US Navy has SCUBA tanks covered, me myself and I would be more concerned with the flood of low cost filter housing from overseas markets. On filter I sent back to Amazon shows a tube weld had failed. He lived! This one:
Amazon.com
www.amazon.com
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What do you mean by” a tube weld had failed”. I don’t have one of those filters. Curious where a welded component is used.
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Maybe look at the link I sent? There is only one tube I know of, right? Look under reviews...
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Wow. According to the specs the product , main components are 7075 aluminum. It would be made from extruded tube or bored out solid bar, which is unlikely. There’s no such thing as welded seam 7075 aluminum tubing. 7075 aluminum is not a weldable aluminum.
That tube was either over pressurized or it was defective in some way, such as wrong heat treatment or a crack.
In any case, that guy was lucky he was not injured or killed.
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