Ten Year Old Cylinder Rule

[Fred Mannis]

This has been mentioned a few times now as one of the new for 2009 ISSF rules. I don't yet have a copy of the new rules, so have not read it, but does it allow for for cylinders that have been hydrostaticaly tested and passed. like SCBA tanks? If not, it is another great example of ISSF not caring about the great mass of club shooters that support the sport.

[TerryKuz]

Fred, In general, I think it is a good idea to pitch the cylinders in ten years. Depending upon the type of scuba tank, they also have a limited lifetime where they are not legal to be re-certified.
Certainly cost is an issue, but divided by 10 years the cost of a new cylinder is minimal. In my mind a new cylinder and 5000 pellets equals, one case of practice 22s, so after the first 5000 rounds the air cylinder is paid for, and a shooter is then saving on ammo. I think the minimal cost of cylinder replacement is appropriate considering the safety implications.
I don't know it is in the rules, but for everyone's safety, the cylinders should be replaced in ten years. Ter

[Richard H]

Scuba tanks and cylinders for rifles and pistol although they serve the same function are vastly different. For starters pistol and rifle cylinders are machined from solid aluminum billets which gives that much great structural integrity than those of scuba tanks.

I know of no one that Hydrostatically tests pistol?rifle cylinders. Considering the cost the hydrostatic test alone, then putting the cylinder back together and replacing seals, it would approach the cost of a new cylinder.

Can anyone point me to anywhere in a manual where it says 10 years? I have three Steyrs and I can find anywhere where it says to discard cylinders after ten years. I would think this is highly subjective as it would really not take into any consideration the usage, I have a hard time believing that someone who shoots once a week and someone who shoots everyday would stress a cylinder to the same level.

[David Levene]

Rule 6.2.2.8
It is the shooter’s responsibility that any air or Co2 cylinder has been certified as safe and is still within the validity date.

[Richard H]

What is the validity date?

FWB P44 says they should be disposed of after 10 years on page 38 of the manual, but I can't find anyhting similar in Steyr manuals.

Walther 300XT manual says 10 years too.

Morini I don't know, their web site seems to be out of action.

[cmj]

A ten year rule also will mean that the effective life of a lot of equipment will be ten years as in the case of the Hammerli air rifle. Already can not get new air cylinders.

[Misny]

What brought this rule about? Have there been some cases of people injured while using older cylinders?

[Muffo]

10 years seems to be a standard time frame for most pressurised things, like gas tanks for cars and bbqs ect

[Richard H]

10 years seems to be a standard time frame for most pressurised things, like gas tanks for cars and bbqs ect

You guys get new gas tanks every 10 yrs for your cars?

[Spencer]

gas tank - as in LPG tank; not gas as in gasoline

Spencer

[Fred Mannis]

10 years seems to be a standard time frame for most pressurised things, like gas tanks for cars and bbqs ect

What makes 10 years "a standard time"? Different 'pressurized things' have different internal pressures, materials of construction, working environments, etc.

At $175 per cylinder these days, I don't seen $17.50 per year as 'cheap'.
It also means that the resale prices of air guns will now be dependent on remaining cylinder life.

Is there any data from the airgun manufacturers that suggests a 10 year life? Nobody has yet provided a basis for ISSF selecting ten years, if that is what the validity date is.

[TerryKuz]

Here is a link to Anschutz concerning the ten year rule.
http://jga.anschuetz-sport.com/index.ph ... %250C%2593




Here is a picture of a ruptured cylinder. Fatigue can come from many processes, but personally I am concerned with corrosion or fatigue where the manometer threads in the cylinder. Cylinders can also be stressed by plane travel, heat, and shock from being dropped. As discussed above, all pressurized cylinders have a set lifetime, 10 years for a 200 dollar cylinder is an acceptable safety cost for me. Even with the cost of cylinders, pellets are very economical compared to Eley EPS, or the cost of gasoline to get to matches for ten years.
I think it is a minor cost to prevent an accident. I wish there was no cost, but over ten years, 20 dollars annually seems prudent to prevent accidents.
My background is material engineering, and I often used pressurized gas to make products. As a whole we ( engineers that process with high pressure gas) consider pressurized gas dangerous, and we take great lengths to minimize potential problems. So from a professional viewpoint, I am very biased to minimize risk at any cost.

(I also made the post before seeing Fred's post above mine. This post was not made to refute Fred, it is just an independent opinion.)

[jackh]

Are replacement Hammerli 480K2 cylinders still available. The milk bottle shaped ones

The "junior" ones fit too.

[Fred Mannis]

Refutation accepted :-)

Given Anschutz' statement, and assuming that the other cylinder manufacturers use similar designs, I can accept 10 years as a reasonable cylinder life.

[Fred Mannis]

Here is a different perspective from Edster99, published in a similar thread last tyear:

Based on a few years exerience dealing with large numbers of scuba cylinders its certainly the case that if they dont suffer from internal corrosion they will last indefinitely. Generally test pressure is set at working pressure plus 50%. This is then tested for the total level of residual deformation after loading to this pressure. Bursting pressure of a 'sound' cylinder is very much higher, and often it is the fittings that fail not the cylinder itself (i.e. the valve in the top). For scuba cylinders a notional number of charging cycles before failure at test due to fatigue is expected at around 10,000. Now thats a lot of cycles !!! Despite news stories to the contrary, corroded cylinders rarely rupture catastrophically blowing shards of shrapnel around, but more often 'tear' open releasing the gas inside in a very exciting but less dangerous way.
Its possible to get steel cylinders rusty inside if they are charged with damp air, slowly leading to failure - especially if they are used for rich oxygen mixes - but the aluminium cylinders primarily found on APs are less susceptible to corrosion. Just dont put salty water in them!

[Bill177]

Would the same apply to Co2 cylinders? I read the Anschutz information and saw no mention about Co2 cylinders.

They operate at considerably less pressure - roughly half of that used in compressed air cylinders.

I do know that the large Co2 tanks must be inspected periodically - my supplier takes care of this for me.

Any info or links?

[Ken O]

I just don't buy it that they go bad in 10 years. I'm a retired welder/fabricater, the acetylene and oxygen bottles supplied by the gas companies had the stamps of the hydro dates on them. Many of the bottles went back 100 years, and were still hydroing good even though the metalergy was nothing as it is now., Whats going to wear out? The oxygen bottles were around 2500 PSI range which is much more stress because the bottle is bigger.

Anshutz has defective cylinders out there, I had one on my 8002. I'm guessing thats what the pic is, and putting out the "10 years and it goes bad" might get someone to get rid of defective cylinder they weren't aware of. I would rather have a older cylinder that I knew was good, than a new one that could be defective.

[Muffo]

10 years seems to be a standard time frame for most pressurised things, like gas tanks for cars and bbqs ect

What makes 10 years "a standard time"? Different 'pressurized things' have different internal pressures, materials of construction, working environments, etc.

At $175 per cylinder these days, I don't seen $17.50 per year as 'cheap'.
It also means that the resale prices of air guns will now be dependent on remaining cylinder life.

Is there any data from the airgun manufacturers that suggests a 10 year life? Nobody has yet provided a basis for ISSF selecting ten years, if that is what the validity date is.

Its not a stansard time that things go bad but In a lot of pressurised applications they are required to be tested every 10 years. we dont have to get new lpg tanks every 10 yers we just have to have them tested

[Richard H]

That's the problem there are no provisions to test these cylinders. Standard. Cylinders are simple they pop the valve off do a visual, and a hydrostatic test. No one does this for these small pistol and rifle cylinders. The cost of having these tested would most likely be around 50% of a new cylinder, so it doesn't make much sense.

[Richard H]

I think people also question the motive of the Mfg, with regards to this 10 year lifespan too. With good reason this lifespan issue is pretty new, they didn't have much to say about it when they started selling these pistols in in the late '90's

It's a pretty good way to keep a revenue stream, a LP10 cost $1895 and every ten years they want you to change your cylinders at 2x$175=$350. So every ten years you fork over approx. 20% the value of the pistol.

Comparing air pistol cylinders to other types of pressure vessels without any study is a little off to. Look at scuba tanks and propane BBQ cylinders, they are both subject to much harsher environments than airgun cylinders, yet what is the 10 year failure rate for these cylinders?

The manufactures could make it a little easier to swallow if maybe they came up with a core charge for cylinders. An example you pay your $175/cylinder and when you return them you say get 25-30% back. I think many question the fact of profit motive in the guise of a safety issue. There really is no information with regards to these cylinders useful lifespan. The are different than many bigger pressure vessels, they aren't made from tubing, or drawn or welded, they are machined from solid aluminum billets.

If the manufactures did core exchanges they actually could do testing and find out what the lifespan is.