TargetTalk

I asked this question a year ago and got no replies.

Worldwide, over the 20+ years that we have been using CO2 and CA in precision air gun shooting, how many catastrophic failures of cylinders have been documented?? What are the particulars of each incident? Of these, how many have produced any injuries??

This question is not meant to re-hash the debate of whether or not we should have cylinder expiration dates - for national and international level matches we are pretty much stuck with them. I would just like to know about failures that have occurred.

This is an excellent question, and I'll be interested to see if any of the vocal predictors of imminent catastrophe from newly out-of-date cylinders speaks up.

And I have a related question that I've asked before and no one answered. Why does it appear that ONLY the 10 meter cylinders require dating, among all the many kinds of small PCP containers on or attached to all the currently available airguns? The non-10-meter PCP airguns vastly outnumber the 10 meter guns, so shouldn't manufacturers and users be worried about the danger from them? Why do they apparently pose no liability problem?

I agree with PaulB that it's now pointless to discuss the dating rule for 10 meter - it's a done deal and competitors at the larger matches have to cope. But many of us are non-competitors, due to age or inclination, so I'd really like to understand why out-of-date air cylinders are supposed to be such a danger to us.

FredB

I just had a cylinder failure on a newer cylinder
As I was unscrewing a cylinder with about 150 Barr in it the last few (2) threads separated and the cylinder jumped out of my hand.
No damage to me it just popped off the last few threads
I sent it in to that manuf. and they sent out a new one
End of story Do not try and read any thing else into it
Dennis

I have two cylinders fail at the same time. Both are exactly twenty years old when they fail. Nothing spectacular, within a week both of them decided not to hold the air any more, as if you try to pump a tire that has a slow leak. I just found it fascinating that they lasted for exactly twenty years.
At no time did I think there would be an explosion or any sort of spectacular events would happen.
Right now all my practice cylinders are 15 years old, work well, and I expect when they fail they will fail the same way. No explosion...

SuperIIFT wrote:I just had a cylinder failure on a newer cylinder
As I was unscrewing a cylinder with about 150 Barr in it the last few (2) threads separated and the cylinder jumped out of my hand.
No damage to me it just popped off the last few threads
I sent it in to that manuf. and they sent out a new one
End of story Do not try and read any thing else into it
Dennis

conradin wrote:I have two cylinders fail at the same time. Both are exactly twenty years old when they fail. Nothing spectacular, within a week both of them decided not to hold the air any more, as if you try to pump a tire that has a slow leak. I just found it fascinating that they lasted for exactly twenty years.
At no time did I think there would be an explosion or any sort of spectacular events would happen.
Right now all my practice cylinders are 15 years old, work well, and I expect when they fail they will fail the same way. No explosion...

are these 'catastrophic cylinder failures'?

Vince's failures sound much more like seal failure. Although annoying that is not really a big issue, very easy to get a new set of seals fitted. Many of the sporting rifles, especially the ones made in the UK, where we don't seem to have a problem with manufactures incorporating the cylinder in the rifle as a non removable component don't have any problems. I have visited the Daystate factory, and the sales manager (Tony Belas) that showed me around reckoned that the air cylinder was good for 50 years, but might need resealing. Oh and that would include filling it in the field with a stirrup pump! They have no concerns over corrosion.

Alan

You might look at this:

https://www.youtube.com/watch?v=TjxZ6MrBl9E

BigAl wrote:Vince's failures sound much more like seal failure. Although annoying that is not really a big issue, very easy to get a new set of seals fitted. Many of the sporting rifles, especially the ones made in the UK, where we don't seem to have a problem with manufactures incorporating the cylinder in the rifle as a non removable component don't have any problems. I have visited the Daystate factory, and the sales manager (Tony Belas) that showed me around reckoned that the air cylinder was good for 50 years, but might need resealing. Oh and that would include filling it in the field with a stirrup pump! They have no concerns over corrosion.

Alan

Oh great, I threw them away...should have kept them :( I sprayed them into some fun colors.

You'll find everything you want to know right here:


search.php?search_id=574212454&start=0

If there are no reports of failures then the system is working, if the seals/valves fail before the cylinder does that's a good thing.

An airgun cylinder supposedly has as much embodied energy as a stick of dynamite - is it really such a chore to change cylinders every ten years?

Yes there are stories of cylinders lasting thirty years, just as there are stories of 40-a-day smokers making it into their 90s.

Corrosion and fatigue are both dealt with by probabilistic approaches, just like cancer, this should make people think.

So did you mean it is possible to have a kaboom?

Aluminum fatigues, progressively. Bicycle handlebars may be a good point of comparison. Most of those are aluminum. A sensible bike racer would not use the same set of handlebars for more than a few years, as the millions of stress cycles inevitably weaken the bars, and a handlebar coming off during a critical sprint would cost them a victory. The potential price paid with airgun cylinders is certainly no less serious, and potentially more dangerous. Failure seems unlikely while pressure is being let off (while shooting), much more likely while filling (or unintentionally overfilling), at which time the proximity of the shooter's face would seem to indicate that such an incident would have unhappy results.

Aluminium's tendency to weaken over time spooks me enough that I think it's probably a good idea to have some sort of safeguard in place. I just don't happen to agree that a time limit is necessarily the fairest way to implement it. For instance, I've shot less than 1 tin of pellets through my K12 since March due to a persistent elbow injury. It's almost healed, but I'm taking it easy to be sure. I've filled my cylinders only twice in that time. Cycling the pressure is what fatigues them, just as loading and unloading firearm magazines is what fatigues the springs and leaving them loaded or unloaded for long periods does not. But I understand that implementation of a rule around numbers of fill cycles and maximum pressures used would be challenging, at least until we see microchip recording in every cylinder, a sort of 'black box' for air gunners. If/when that happens it'd be easy enough to just plug your cylinder's USB port into a computer at equipment check and see a pass or fail indicator based on industry standard tests. We're obviously not there yet. So I guess we're stuck with the 10 years they came up with, and cylinder sales aside, I'm sure they had their reasons.

And of course everyone can go ahead and shoot way, waaaaaaaay beyond that limit at home or the local club or wherever you can get away with it.

JamesH wrote:If there are no reports of failures then the system is working, if the seals/valves fail before the cylinder does that's a good thing.

An airgun cylinder supposedly has as much embodied energy as a stick of dynamite - is it really such a chore to change cylinders every ten years?

Yes there are stories of cylinders lasting thirty years, just as there are stories of 40-a-day smokers making it into their 90s.

Corrosion and fatigue are both dealt with by probabilistic approaches, just like cancer, this should make people think.

Totally misses the point and is non-responsive to the original post question.

The OP asked for actual examples - not hypothetical fear-mongering - of catastrophic cylinder failure. No one has posted such an example, and examples of seal failures are irrelevant.

My follow-up question essentially asked why "the system" was different for 10M PCP airguns than for the more numerous non-10M PCPs, often made by the same manufacturer. The no-dating "system" apparently works just as well as the dating "system", which in any case is quite recent.

Where are the actual examples of catastrophic failure? Hypotheticals don't count.

Bada bing, bada boom!

I've charged my cylinder (FWB 700) maybe 1000 times in the past 3 years and have yet to have even the slightest leak. The only thing wrong with my cylinder is a crack in the manometer glass from poor handling at the airport.

Why stress out over this subject when you can...:

viewtopic.php?t=46430

Rover, you are a one-trick pony.

I've charged my cylinder (FWB 700) maybe 1000 times in the past 3 years and have yet to have even the slightest leak.

Cylinder failure isn't like any leak you're likely to have ever encountered.

Willie, I sincerely believe what I'm telling these guys, but what do they know about "experience".

All I see is bozos puking up what they've read on the 'net, no matter that they can't shoot worth shit. Then there are the guys taking what they say as "gospel".

But, then, what the hell do I know!

BTW I have to admit I DO post some of this stuff just to annoy them.

I've been working on this issue from the "Transportation" angle for years... replacing cylinders is about selling more expensive cylinders. You can use the "risk argument" in any way and in a million ways to justify spending money needlessly. There is no evidence that I've ever found of "catastrophic" failure unless someone is unscrewing the cylinder with a large wrench, (while the cylinder is installed on the rifle / pistol) and specifically not following manufactures warnings. Newer cylinders now have a small hole that will release pressure prior to the ends fully unscrewing from the cylinder. I've talked to folks that have left full (charged) cylinders in hot cars, flown them around the world on aircraft, and shipped them. Cylinders have been run over by forklifts and vehicles, and not one single example of a catastrophic failure...

Now, let the games begin...

Do pressure sometime vessels fail? Yes they do.

Do aluminium parts sometime fail catastrophically? Despite an immense amount of care and attention airliners do still fall out of the sky.

Do aluminium pressure vessels sometimes fail? Yes, although scuba tanks are tested and inspected annually, and often scrapped well before they're really dangerous, they still sometimes fail unexpectedly with severe consequences.

Has anyone seen an airgun cylinder fail yet? Maybe not, but it will happen.

Competition organisers don't want the liability on their head so they take a cautious approach.

People can use old cylinders to their hearts content on their own property, club etc, if they want to go to an organised competition they need a cylinder which is less than ten years old.
For an average ~$10/year I just don't see that its a big deal - what is that - one tin of match pellets?

Or we could gripe and moan and maybe we'll achieve a victory and the system will be changed so we can pay a $20 annual inspection fee to continue using old cylinders.