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Steyr LP10 Air Cylinder Questions

Posted: Thu Jul 24, 2014 6:03 pm
by Scrench
Does anyone know the cc volume of the long and short air cylinders?

Does anyone know of a way to unscrew the air cylinder from the fill adapter without losing a bunch of air? No matter how fast I try to unscrew it from the adapter, which is screwed into the K valve on my scuba tank, it seems like I lose a lot of air. Any way around this to keep a full charge?

Thanks,

Scrench

Posted: Thu Jul 24, 2014 7:23 pm
by j-team
Most of that air you hear escape is the pressurised air in the yoke and adaptor rather than from your cylinder. I wouldn't worry about it.

Posted: Fri Jul 25, 2014 1:18 am
by dddstudio
Check the pressure gauge after you unscrew it. If it is around 200 bar, you are fine. Also if the small drop of pressure really concerns you, maybe try filling it just a hair above 200 bar. Also note that cooling also decreases the pressure a bit (when you fill it up it get warmer).

Posted: Fri Jul 25, 2014 9:44 am
by Brian Girling
The compact cylinder is 0.07L it's printed on it.


As the gun cylinder is unscrewed its valve closes before the seal is 'broken' therefore air can not be released from the cylinder only the connecting pipework.

Posted: Sun Jul 27, 2014 11:34 am
by markwarren
I have bought a fill adapter which allows you to bleed the system before you take the cylinder off. This means the cylinders is unscrewed without any pressure on the threads which personally I prefer. They are made by a company called Best Fittings here in the UK.

Good shooting

Mark

Posted: Sun Jul 27, 2014 11:41 am
by Rover
We at the club have one of those devices, but it will drain a Steyr cylinder. Does yours not do the same?

not for Steyr

Posted: Sun Jul 27, 2014 12:14 pm
by FredB
markwarren wrote:I have bought a fill adapter which allows you to bleed the system before you take the cylinder off. This means the cylinders is unscrewed without any pressure on the threads which personally I prefer. They are made by a company called Best Fittings here in the UK.

Good shooting

Mark
That works for Morini cylinders, but not for Steyr. Different valve setup.

Posted: Sun Jul 27, 2014 12:14 pm
by Gwhite
With the Steyr, you just need to back off the cylinder a turn or two first, or the vent will drain your cylinder.

Posted: Mon Jul 28, 2014 3:41 pm
by BobSki
Gwhite wrote:With the Steyr, you just need to back off the cylinder a turn or two first, or the vent will drain your cylinder.
+1

Just unscrew the cylinder 1 turn, THEN open the bleed valve.

Posted: Mon Jul 28, 2014 5:42 pm
by Rover
Why bother with all this; just unscrew it.

Posted: Mon Jul 28, 2014 6:20 pm
by Gwhite
The difference may be minor, but it puts extra wear & tear on the threads. What's worse, as you unscrew the cylinder, the strength of the threaded connection goes down, as the force from the air is supported by fewer & fewer threads. Over time, this will tend to mess up the last couple threads on both the cylinder & the adapter.

Posted: Mon Jul 28, 2014 7:48 pm
by Rover
Oh, BS!

Posted: Mon Jul 28, 2014 7:57 pm
by Gwhite
Do you have an engineering background to support that statement, or are you just spouting hot air (as per usual)?

I said the difference may be minor, but the rest of my statement is not a matter of conjecture. The forces are there, the support is reduced, and there WILL be accelerated wear on the last couple threads. All of which can be avoided if you vent the pressure as soon as you have unscrewed the cylinder enough to close the internal valve.

If you do not wish to treat your equipment with that degree of extra care, go right ahead.

Posted: Mon Jul 28, 2014 9:05 pm
by Rover
I'll keep it simple for you engineering types.

After about one turn of the cylinder the pressure has completely vented. You cannot use some device to vent a Steyr cylinder; you must unscrew it a little bit. Therefore, after that has occurred you are doing no more than unscrewing the cylinder.

If you fear that is wearing out the gun and cylinder, I offer no help. Perhaps your Steyr is different from mine and many others I've seen.

Posted: Mon Jul 28, 2014 11:26 pm
by j-team
Gwhite wrote:The difference may be minor, but it puts extra wear & tear on the threads. What's worse, as you unscrew the cylinder, the strength of the threaded connection goes down, as the force from the air is supported by fewer & fewer threads. Over time, this will tend to mess up the last couple threads on both the cylinder & the adapter.
I hope you have allowed for the fact that the volume of the trapped air is increasing as you unscrew the cylinder therefore reducing in pressure and so reducing the force on the thread...

I agree with Rover. Just unscrew the thing, the cylinder will be expired before the thread wears out!

Re: not for Steyr

Posted: Wed Jul 30, 2014 4:23 am
by markwarren
FredB wrote:
markwarren wrote:I have bought a fill adapter which allows you to bleed the system before you take the cylinder off. This means the cylinders is unscrewed without any pressure on the threads which personally I prefer. They are made by a company called Best Fittings here in the UK.

Good shooting

Mark
That works for Morini cylinders, but not for Steyr. Different valve setup.
Fred - I have one and it works fine on the Steyr thank you! I can bleed the system before I take the cylinder off.

Posted: Wed Jul 30, 2014 4:25 am
by markwarren
Rover wrote:I'll keep it simple for you engineering types.

After about one turn of the cylinder the pressure has completely vented. You cannot use some device to vent a Steyr cylinder; you must unscrew it a little bit. Therefore, after that has occurred you are doing no more than unscrewing the cylinder.

If you fear that is wearing out the gun and cylinder, I offer no help. Perhaps your Steyr is different from mine and many others I've seen.



Yes you can.

I am not an engineering type but I have one and it works. Don't know what else to say really!

Re: not for Steyr

Posted: Wed Jul 30, 2014 11:51 am
by FredB
markwarren wrote:
FredB wrote:
markwarren wrote:I have bought a fill adapter which allows you to bleed the system before you take the cylinder off. This means the cylinders is unscrewed without any pressure on the threads which personally I prefer. They are made by a company called Best Fittings here in the UK.

Good shooting

Mark
That works for Morini cylinders, but not for Steyr. Different valve setup.
Fred - I have one and it works fine on the Steyr thank you! I can bleed the system before I take the cylinder off.
Mark,
It's hard to argue with actual experience. Would you please give us more details - possibly photos - about your fill adapter? I can't imagine an arrangement that would allow what you describe, but I don't claim to have an unlimited imagination.

Posted: Wed Jul 30, 2014 1:35 pm
by Rover
I'd be curious, too. I have one and it does not work as you describe. We also have such a device on the compressor we use to fill single cylinders at my club. It doesn't work, either.

It WILL work if you back off the cylinder until the valve in it closes, THEN bleed the air.

By that time the air in the system has probably bled out.

As I said, not worth the trouble. I have the two original cylinders (with the pop-out fill indicators and way out of date) and they still work fine.

Hey, Scott....how about kicking in on this one (and get some REAL experience going).

Posted: Wed Jul 30, 2014 6:01 pm
by pilkguns
I got back from Perry last night late Been up there 3 times in the last 5 weeks.

As to this thread, I have never seen Steyr threads needing replaced from wear on either the adapter, cylinder. or regulator. Honestly of all the manufacturers, Steyr threads seem to be the most trouble free.