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AP:Expired seldom used cylinders vs New daily used cylinders

Posted: Tue Jul 23, 2013 2:00 am
by conradin
Do cylinder fail due to age, or due to use? If I have a new old stock 20 years old cylinder that only been used for a dozen times, vs a new cylinder that has 5 years left but was used every day, which one is actually more reliable, and actually has a longer life? Is there a way to test the cylinders how much life they have left?

Posted: Tue Jul 23, 2013 3:27 am
by Gerard
I'd be more concerned about the valve integrity of am older cylinder, and perhaps construction standards. Aluminum has a limited lifespan in terms of flexion cycles, whether that's bending or internal pressure. So the actual danger comes from usage, not idle aging. And of course no larger match is going to allow you to use old cylinders.

Re: AP:Expired seldom used cylinders vs New daily used cylin

Posted: Tue Jul 23, 2013 5:50 am
by Spencer
conradin wrote:Do cylinder fail due to age, or due to use? If I have a new old stock 20 years old cylinder that only been used for a dozen times, vs a new cylinder that has 5 years left but was used every day, which one is actually more reliable, and actually has a longer life? Is there a way to test the cylinders how much life they have left?
Fail, as is start leaking, or fail as in catastrophic?

Re: AP:Expired seldom used cylinders vs New daily used cylin

Posted: Tue Jul 23, 2013 9:34 am
by GOVTMODEL
conradin wrote:Do cylinder fail due to age, or due to use?
A combination. A cylinder fatigues due to the cyclic nature of the stresses from filling and emptying. Steel cylinders are also prone to rust.
conradin wrote:Is there a way to test the cylinders how much life they have left?
Not to my knowledge.

I suspect that inspecting the interior of a cylinder isn't practical, and that's why you don't see shops offering inspection and hydro-static testing of airgun cylinders.

The ISSF rules seem to simply have a cut-off age, which makes the business of inspection and hydro even less lucrative.

Posted: Tue Jul 23, 2013 10:35 am
by Tycho
I'm still waiting to see proof of a cylinder that failed due to age. The only ones I know of where Anschutz air rifle cylinders that burst - after only 6 months or so, due to faulty production. And we've seen Morini manometers take off toward the ceiling, but that was a problem of the manometer threads. Otherwise, all rumours.

and furthermore...

Posted: Tue Jul 23, 2013 11:15 am
by FredB
And here's another fact to ponder. There are now a huge number of non-target PCP guns in use and being made. To the best of my knowledge, none of these guns come with any kind of warning about dangers due to aging; indeed they barely, if at all, even mention dangers due to over-filling. I haven't heard of any catastrophic failures from these types of guns (doesn't mean none has happened, just not highly publicized).

These guns' manufacturers are located all over the world, including the lawsuit-happy USA. Don't you think that, if there were truly any significant danger, at least the USA manufacturer lawyers would be all over their bosses to plaster warnings on the guns and packaging? Why aren't these manufacturers telling their customers to stop using their guns after 10 years? Is it so much more dangerous to use a PCP in an ISSF competition?

Just askin'.

FredB

Posted: Tue Jul 23, 2013 11:26 am
by Gerard
A fairly obvious suggestion arising out of your observation, FredB, would seem to be the possibility of collusion for profit between the ISSF and the cylinder manufacturers. No?

Posted: Tue Jul 23, 2013 11:57 am
by Bob-Riegl
While Gerard's suspicion may be thinkable but hardly the problem. This whole thing blew up recently when new ISSF rules were "discovered" re: cylinder age. The average everyday pcp unit used by us peasants, gets filled once or twice a month. Personally I use a manual pump, "hard work" but reliable---I sincerely think that kind of refilling is kinder to the cylinders than scuba tanks with initial pressures of several thousand lbs./sq. in.. This has stirred up a minority of persons in the AP shooting community for no good reason. I know air pistols and CO2 pistols that have been around for years, with none the worse re: new ISSF rules. The ISSF has nothing better to do than constantly make the international shooting community hysterical about various and sundry "new" or changed rules. Just remember the arrival of the shooting jackets, pants and shoes on the ISSF rules and their recent changes. Somebody rightly said "hey these clothes are a true support for rifle shooters"---calm down and don't get caught up in the hysteria of the moment Conradin. "Doc"

Re: AP:Expired seldom used cylinders vs New daily used cylin

Posted: Tue Jul 23, 2013 3:25 pm
by j-team
conradin wrote:Is there a way to test the cylinders how much life they have left?
Yes. Wait till it blows up, then you will know how much life it had left.

Anything else is an estimate.

Posted: Tue Jul 23, 2013 3:54 pm
by Tycho
That's why you have two cylinders ;-)

Re: AP:Expired seldom used cylinders vs New daily used cylin

Posted: Tue Jul 23, 2013 3:58 pm
by conradin
Spencer wrote:
conradin wrote:Do cylinder fail due to age, or due to use? If I have a new old stock 20 years old cylinder that only been used for a dozen times, vs a new cylinder that has 5 years left but was used every day, which one is actually more reliable, and actually has a longer life? Is there a way to test the cylinders how much life they have left?
Fail, as is start leaking, or fail as in catastrophic?
My 20 year old ones start to leak, and also apparently cannot give consistent air pressure. After70 shots it is done. So right now I am concerned about the 14 years old ones, which seems to be seldom ever used (from Pilk). I don't know whether this is new old stock, or old stock that has been used extensively.

Posted: Tue Jul 23, 2013 4:08 pm
by j-team
Tycho wrote:That's why you have two cylinders ;-)
And two hands!

Posted: Tue Jul 23, 2013 9:21 pm
by Chris
I would look the seals and see if they are still in a good condition. Rubber does not last for ever and will dry and crack.

Posted: Tue Jul 23, 2013 9:55 pm
by Rover
If the cylinders are the ones that came with the LP1 (with the "tit" fill indicators), they are almost certainly "belly up" but repairable. Have the indicators disabled during the rebuild since they are troublesome and generally worthless.

Posted: Wed Jul 24, 2013 3:25 am
by conradin
Rover wrote:If the cylinders are the ones that came with the LP1 (with the "tit" fill indicators), they are almost certainly "belly up" but repairable. Have the indicators disabled during the rebuild since they are troublesome and generally worthless.
Yes they are the nipples one. Would you please explain what you wrote? (belly up) So far they seemed to be OK, but who knows.

The long term solution is simply to purchase new cylinders.

Posted: Wed Jul 24, 2013 4:33 am
by Gerard
When a fish dies it floats 'belly up'.

Posted: Wed Jul 24, 2013 11:35 am
by conradin
How can I tell if the 14 years old ones are losing it?

Posted: Wed Jul 24, 2013 11:42 am
by Rover
I did myself what I told you to do. I sent them one at a time when each started to leak so I still had a gun. The nipples usually start to leak first. Disabling them cures this. You can tell when a cylinder is "losing it" when it doesn't hold air.

I'm still using both with no problems. With your luck, the cylinders will probably dynamite the neighborhood. Buy a new cylinder shortly before your first World Cup or Olympics.

BTW From now on do a search. Almost all your questions have been beaten to death on this forum.

Posted: Wed Jul 24, 2013 12:01 pm
by David Levene
Rover wrote:I did myself what I told you to do. I sent them one at a time when each started to leak so I still had a gun. The nipples usually start to leak first. Disabling them cures this. You can tell when a cylinder is "losing it" when it doesn't hold air.

I'm still using both with no problems. With your luck, the cylinders will probably dynamite the neighborhood. Buy a new cylinder shortly before your first World Cup or Olympics.

BTW From now on do a search. Almost all your questions have been beaten to death on this forum.
...or a USA Shootingevent.

Posted: Wed Jul 24, 2013 1:44 pm
by conradin
Rover wrote: The nipples usually start to leak first. Disabling them cures this.
Can you teach me about disabling them and check for leak at the nipples?
Rover wrote:
BTW From now on do a search. Almost all your questions have been beaten to death on this forum.
Before my fist ever post, I read the entire archive...