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PostPosted: Sat Mar 04, 2017 12:06 pm 
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Posts: 343
Both of my cylinders are leaking air now.

Taken off pump, start hissing, screw on pistol, shoots OK, no leak.

I think both cylinder seals need to be changed.

Need recommendation for the three prong wrench used to open cylinder.

Would the three prong wrench used to open watch caseback work?


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PostPosted: Sat Mar 04, 2017 12:22 pm 
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of course, for safety, I will release all pressure off cylinder before opening the cylinder.


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PostPosted: Sat Mar 04, 2017 7:46 pm 
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Location: Sugar Run, Pa
http://www.network54.com/Forum/79537/th ... isassembly


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PostPosted: Sat Mar 04, 2017 11:06 pm 
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wow, that is a long run for a short slide.

Isn't there a three-prong wrench for opening those three hole screw?


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PostPosted: Sun Mar 05, 2017 12:24 am 
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Location: czech republic
yes, there is the one that you made, it's easy.
there is the more difficult task not damage of the cylinder surface and cylinder shape
when unscrewing the cylinder cap, be careful
sorry, it is easy to damage the anodized layer and to make a sharp notch


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PostPosted: Sun Mar 05, 2017 1:59 am 
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Location: Costa Rica, Central America
seamaster wrote:
Would the three prong wrench used to open watch caseback work?

No, the watch case opener does not have the torque to open the valve end of the air cylinder.

You can ask a local machinist to make you the 3 prong spanner wrench with a long handle or
simply ask Steyr Sport to see which wrench they're using to assemble their cylinders.


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PostPosted: Sun Mar 05, 2017 2:35 am 
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It seems if you can open them up, you can do a visual inspection. Why can't these be visually inspected, hydro-tested, and recertified every couple years like scuba tanks?


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PostPosted: Sun Mar 05, 2017 8:50 am 
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Location: Massachusetts
They could, but the rules don't have an exemption for recertification. Date of manufacture is all it says.

The other issue is that every vendor's cylinders are different. If someone were to offer it as a service, they would need a collection of different tools, seals & fittings to do the testing. It's doable, but a bit of a pain to set up. The manufacturers could do it, or even recylcle valves & gauges on new cylinder walls.

Step 1 would be to get the ISSF to formally allow it. Given that the vendors make lots of money selling cylinders to everyone, they would much rather sell a cylinder for $200 than charge $50 for recertification. I have heard more than one person claim that the 10 year limit is primarily a money making dodge and has nothing to do with safety. Morini & Hammerli had no problem certifying their cylinders for 20 years before the rules change, so there is no technical reason why it couldn't be done.

If (as some people claim) the real problem is the number of cycles of expanding & contracting an aluminum cylinder under goes, then they should install counters that track the number of times a cylinder has cycled through a significant pressure change. A 5 year old cylinder that has been fired down to 80 bar and refilled every week is far more likely to fail than a 20 year old cylinder that is topped off after every practice session.


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PostPosted: Sun Mar 05, 2017 11:18 am 
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Location: czech republic
Above all, 10 years is a mere administrative act.
Cylinders, which so far have been ruptured by the quality of the material, the process of producing bad or poor design. In a well-designed cylinder should be much lower operational than the yield strength of the material and its durability can not therefore decide the number of pressurizing cycles. During long time operation cylinder will be under the influence of external mechanical damage and corrosion attack of the outer and inner surfaces. It's damage are very well visually observable.
On the other hand ISSF rules are clearly specified. We do not create it, we are only respected even if they are sometimes strange.
Boundary of 10 years is very very safe until it is pointless. And it is unsurpassed for ISSF competitions. That is the reality.

P.S. Air pistol cylinders can in no way compare scuba diving tanks, whose stress is a much greater and destruction and their consequences are much more serious.


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PostPosted: Sun Mar 05, 2017 5:35 pm 
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Location: Hamilton Square NJ
kevinkunkle wrote:
http://www.network54.com/Forum/79537/thread/1428705848/Steyr+Air+tube+disassembly


WECSOG at its best! All he needs is a Dremel.

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Norm
in beautiful, gun friendly New Jersey


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PostPosted: Mon Mar 06, 2017 12:12 am 
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Got the cylinder opened tonight with that "three-screw through wood stick" wrench technique.

Outer cap seal was cut, but I doubt that is the cause of the leak, because prior to remove the cap, I did a water leak test. Leak was coming off center, not perimeter of the cap.

How many seals are there?


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PostPosted: Mon Mar 06, 2017 12:38 am 
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Location: Aus
http://www.targettalk.org/viewtopic.php?f=4&t=54750#p263940

Image
from original LP10 manual

Code:
Item                Designation                   Standard
72     Propellant cylinder compressed air   
72.1   Cylinder body compressed air   
72.2   Cylinder valve compressed air   
72.3   Valve head   
72.4   Trigger adjusting spring   
72.5   Cylinder valve tappet assy   
72.5.1 Cylinder valve tappet   
72.5.2 Parallel pin                               DIN 6325 2m6x16
72.6   O-ring 20x2   
72.7   Valve body for pressure reducing valve   
72.8   O-ring 2.9x1.9   
72.9   Supporting ring   

29     Pressure reducing valve LP-1   
29.1   Piston assy   
29.2   Adapter for pressure reducing valve   
29.3   Housing for pressure reducing valve   
29.4   Adjusting screw for pressure reducing valve   
29.5   Cover for pressure reducing valve   
29.6   Guiding sleeve   
29.7   O-ring 1.5x1   
29.8   O-ring 8.92x1.83   
29.9   O-ring 4x1.5   
29.10  O-ring 3x1.5   
29.11  Connecting screw   
29.12  Disc spring                                DIN 2093 A 12.5 GR1
29.13  Filter   
13     O-ring 18x2


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PostPosted: Tue Mar 07, 2017 11:55 am 
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Joined: Fri Nov 25, 2005 11:46 am
Posts: 391
Location: Western Washington State, USA
Greetings All,

Since I like taking things apart to see how they work, this post has been most tempting.

Only two O-rings I can see in the cylinder.

Since the O-rings do all the work of sealing, I wonder what torque is recommended for refitting the end cap?

Also, what lubricant, if any, would be used on the threads to prevent galling?

Cheers,

David


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PostPosted: Tue Mar 07, 2017 1:47 pm 
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Joined: Sun Jan 16, 2011 6:24 pm
Posts: 343
How much torque?

A lot !!

Used three prong through wood stick technique. Hard to line up all three screws, was able to line up two prongs. Take a lot of torque. Enough to make hand blister via rubber pad grip on my two hands.

Replaced seals. Working great, pressure up to red line, no leak on water test. Shoot vigorously.


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PostPosted: Sun Mar 12, 2017 2:18 pm 
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Joined: Tue Mar 06, 2007 12:51 am
Posts: 57
Location: czech republic
Do not overdo it with the torque. Tightening adds to the stress from cylinder internal pressure. Be careful.


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PostPosted: Sun Mar 12, 2017 3:39 pm 
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Joined: Sun Jan 16, 2011 6:24 pm
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Torque required, I was talking about opening. Steyr OEM cylinder is very tight. Takes hand blistering torque to open it.

To recap it, hand tightening is with proper seal is very adequate.


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PostPosted: Sun Mar 12, 2017 4:24 pm 
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Location: czech republic
Note: Rubber is incompressible. Poisson's ratio is very high


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PostPosted: Wed Mar 15, 2017 6:03 pm 
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Location: Hamilton Square NJ
pbrejsa wrote:
Note: Rubber is incompressible. Poisson's ratio is very high


True. But it is deformable to match the sealing groove. Once that's been achieved, no more torque.

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in beautiful, gun friendly New Jersey


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