PCP cylinder testing

[nitemax]

Does anyone know if PCP cylinders can be pressure tested and if so, who might do it ?
On a related issue, if a cylinder was to fail would it likely be a split in the steel rather than a full on explosion ?
Thanks

[angrybear]

Well there is no requirement to test a cyl under 500cc's, but if you wanted to I suppose ask the place that does your dive cylinder, or the rifle manufacturer.

If it's a buddy bottle that some moron has drilled & fitted a QF in the base then it's scrap,
if it's a tube that has been part drilled fitting a stud then it's probably scrap if drilled more than 0.5mm or so.

How they fail is more down to why they fail, they usually burst from a weak/failure point so the edges are blown open & peel back due to the force of escaping air, (like they do in cartoon explosions) but if it's due to general corrosion the stresses from the burst could cause the whole thing to shatter.

Burst or split if you were holding it, it would likely rip/blow your hand off.

[nitemax]

Well there is no requirement to test a cyl under 500cc's, but if you wanted to I suppose ask the place that does your dive cylinder, or the rifle manufacturer.

If it's a buddy bottle that some moron has drilled & fitted a QF in the base then it's scrap,
if it's a tube that has been part drilled fitting a stud then it's probably scrap if drilled more than 0.5mm or so.

How they fail is more down to why they fail, they usually burst from a weak/failure point so the edges are blown open & peel back due to the force of escaping air, (like they do in cartoon explosions) but if it's due to general corrosion the stresses from the burst could cause the whole thing to shatter.

Burst or split if you were holding it, it would likely rip/blow your hand off.

Having no requirement to be tested does not mean they are safe.
I have 3 PCP's and they are all pre-anti tamper so if they were dive bottles they would have required at least one pressure test by now.
My hands are something I use on a daily basis !

[angrybear]

True enough but there's hell of a difference in stress between a cyl at 300bar & a rifle tube at under 180bar.

[max headroom]

for testing, a dive shop. my s200 and 400 had numbers on. it told me my test date. some bggrs will say you need to replace the cylinder. the nice peeps say it is well in date.

[nitemax]

for testing, a dive shop. my s200 and 400 had numbers on. it told me my test date. some bggrs will say you need to replace the cylinder. the nice peeps say it is well in date.

One of mine is an S410 so I will check that, are the numbers coded or just straight forward dates ?
The other gun is an FX with a buddy bottle, the bottle has numbers on and I will check those too.
Thanks for the info.

[Peter Dunkley]

How the heck are they going to test them if they do. Do they take them off the gun and manufacture a plug to screw into the end. Also what pressure do they take them up to? i know the AA cylinders are weakened at the threads so this part opens before the cylinder splits. I have read of a few lads putting too much air in and this happening. it does not take much over the test pressure.
I think you are just supposed to buy new.

Nitemax what are you going to do about yours to save your hands?

[nitemax]

Nitemax what are you going to do about yours to save your hands?

Whatever is required, wouldn't you ?
Cylinder testing is something that should to be seriously considered on older PCP guns especially given the rise in popularity of them over the last 20 Years or so.

[max headroom]

One of mine is an S410 so I will check that, are the numbers coded or just straight forward dates ?
The other gun is an FX with a buddy bottle, the bottle has numbers on and I will check those too.
Thanks for the info.

when AA was still in England the bottles were numbered. the last two numbers gave the year. i.e 2471578 means it was made in 1978.

[max headroom]

How the heck are they going to test them if they do. Do they take them off the gun and manufacture a plug to screw into the end. Also what pressure do they take them up to? i know the AA cylinders are weakened at the threads so this part opens before the cylinder splits. I have read of a few lads putting too much air in and this happening. it does not take much over the test pressure.
I think you are just supposed to buy new.

Nitemax what are you going to do about yours to save your hands?

yes. and no. you use a bell diving attachment.

[RobF]

Well there is no requirement to test a cyl under 500cc's...

Where does it say that?

[hareng]

More like theres no requirement to test or periodically test a fixed cylinder sub 500cc. To my knowledge no manufacturer tests every cylinder, usually at best a pre production batch sample.
There are only a couple of producers that may test every cylinder they make, all local within 15 mile.

Any dive shop should be able to test the cylinder but will need the attachment to do so.
If they test to IDAS standards most will fail ie operate at 200bar means test to 300bar.

Steels good unless its rusted internally, aluminium no warning. Manufacturers have been putting dispose by dates on usually 10 years purely to cover themselves for the last 12 years or more.

[angrybear]

Where does it say that?

In the rules for testing compressed gas pressure vessels.

As hareng above has put, there might even be a link in the stickies.

[acmsarh]

After Falcon took over Titan the first off machined gun cylinders were sent to us (MDE) for testing , I set the hydro rig up using the blanks supplied with the cylinders and cycled the first cylinder to 200bar working pressure a number of times and then to test pressure 300bar but it did not get there as at 235 bar one of the blanks blew out across the test room (A mild shock to the system to say the least) , On examination the o'ring seal on the plug was in the wrong place allowing the pressure to act directly on the threads expanding the threads on the cylinder allowing the plug to let go ,The seal should have been at the other end of the blank sealing the threads off from direct pressure ,As the blanks and cylinder sealing areas were to be the same as actual airgun production components all further test's and manufactured components were scrapped as a redesign was needed.

[T 20]

How the heck are they going to test them if they do. Do they take them off the gun and manufacture a plug to screw into the end. Also what pressure do they take them up to? i know the AA cylinders are weakened at the threads so this part opens before the cylinder splits. I have read of a few lads putting too much air in and this happening. it does not take much over the test pressure.
I think you are just supposed to buy new.

Hi Peter.

On my travels I've actually been to the place that BSA buddy bottles are sent to be longevity tested and I've chatted to the chap who built the test rig and did the testing.

From what I could gather the cylinders are measured externally and then screwed onto a hydraulic test rig and then the rig is turned on and left running for a week or two.

During the test the cylinder goes through hundreds of thousands of fill cycles from 0 PSI up to about 500 PSI, after which they are measured again to check for deformation.


I wish I'd paid more attention now.




All the best Mick