Leshiy 2 explodes

Was HOPING that ED would comment on my O-ring placement observation of post #157 ?
I mentioned it in post 16.
Other posts by Travis and Ed concerning this are in posts 109,123

I think there are others but Ed’s reply is post 123. He essentially discounted it (speculated) that it was blown to wrong position during failure. ?

Dave
 
I mentioned it in post 16.
Other posts by Travis and Ed concerning this are in posts 109,123

I think there are others but Ed’s reply is post 123. He essentially discounted it (speculated) that it was blown to wrong position during failure. ?

Dave
Ah, such a Looong thread, only skimmed along. THANKS !!
 
He says he was shooting it when it blew up. Also says he filled to 200bar, went on to mention there was no prior visible damage to the tube. Maybe I will start wearing my full face motorcycle helmet when I shoot my L2 from now on. Keep in mind this was posted on Facebook, lots of fake stuff there, but it seems real.
Make sure the visor is Polycarbonate. I'm pretty sure they are but I'd double check. My Shoei didn't break when I tried to grind my face off with a 80mph get off.
 
Not to sound cocky .. I'm seeing plain as day a GLARING ISSUE :unsure:
On the Fractured tube at threaded end there is a machined area inboard of threads that the Female spigot area of connections O-Ring rests on when fully screwed together. This places the actual sealing ahead of threads, leaving threads in Shear and not radially exposed to pressure .. as it should be.

Tho picture shows NOT ONLY a Sheared away or damage O-ring groove at the end of the female spigot, BUT AN O-RING at shoulder of where tube butts up when fully screwed on ... WTF !!! Ed's shared drawing shows NO SUCH O-RING at that position :oops:

With the O-ring omitted due to perhaps a previous Fupaw of o-rings groove on end of the spigot, one was placed where tube butts up ? .... This alone places pressure Radially on the threads and would create such a failure IMO.
To tell you truth I even cannot imagine that this O-ring can be installed on the wrong place!!! But, if we accept that as the version -- that is complete desaster! :) I assume that it was blown from it's place by the explosure, though how it remain unbroken that is another magic...
 
Ed,

This has been mentioned by 3 different people who actually study and build different pressure containing scenarios. I am not one to dismiss any possibility until final analysis is available.

I did move the oring on one of my spare plenums and you are correct that it is difficult but will get there. Once there, I screwed the tube on. Hand tight, there is a lot of oring exposed. I didn’t try to tighten with tools but if someone did, it would form a seal.

I wouldn’t take anything off the table before completing the investigation.

Thanks Ed for participating here. I’m sure this will get sorted.

Dave
 
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Curious what the findings will be. By the looks and sounds of it that o-ring was installed in the wrong place, though perhaps cold temps have something to do with this 🤷‍♂️. Would be interesting to know if the gun was ever maintained or if this was an issue during assembly by manufacturer/assembler. I see people mention in the UK the user has to piece the gun together, if that's the case then that could easily be the cause for issue without clarity on where all o-rings must be sitting before assembling.
 
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@EDgun

Thanks for all the attention you are putting on this issue. It is clear your technical understanding is beyond reproach on the subject. I am also impressed with your true understanding of what it takes for a manufacture to guarantee their products adhere to the engineering specification and requirements. Just a guess on my part, but maybe the initial failure mode has nothing to do with pressure? Maybe it has to do with a static impact to the rifle? Looking at a bending moment where a hit to the bottle reservoir from below and forward? This location where the tube attaches to the butt would probably see highest possibility to fail from this moment? It would not take much of bending moment to perhaps cause very small damage that could initiate a failure due to pressure? Your standard reservoir with standoff support would not cause such a moment but an unsupported bottle might? You clearly have the tools to study and understand the possibility of the load such a moment would place at the tube at its rear attachment. Just trying to help…
 
That’s an excellent and detailed observation. Whether it’s the cause in this event or not, it might be something to consider putting a simple block between the tank and tube. Creating a point of support similar to the non-tank version of the L2.

Obviously, the safest thing is to handle ANY high pressure vessel with care. I’m starting to think more and more that mishandling lead up to this event.

Dave
 
@EDgun

Thanks for all the attention you are putting on this issue. It is clear your technical understanding is beyond reproach on the subject. I am also impressed with your true understanding of what it takes for a manufacture to guarantee their products adhere to the engineering specification and requirements. Just a guess on my part, but maybe the initial failure mode has nothing to do with pressure? Maybe it has to do with a static impact to the rifle? Looking at a bending moment where a hit to the bottle reservoir from below and forward? This location where the tube attaches to the butt would probably see highest possibility to fail from this moment? It would not take much of bending moment to perhaps cause very small damage that could initiate a failure due to pressure? Your standard reservoir with standoff support would not cause such a moment but an unsupported bottle might? You clearly have the tools to study and understand the possibility of the load such a moment would place at the tube at its rear attachment. Just trying to help…
The best of experiment is
233.png
 
The best of experiment is
View attachment 335490
Totally possible but this example below may be more likely?

I don’t believe this force is nearly enough to cause the total failure damage in the photo (unless the gun was used for a club?). It could take the tube to yield or cause some micro cracking. This initial static damage could easily be the root cause for an ultimate failure under pressure.

If this does prove to be a possibility with testing by Ed I’m not sure what the responsibility of a manufacture would be to mitigate damage caused by misuse, dropping or from a foreign object? If it was easy to mitigate with a design modification I would hope Ed would consider?

I would also like to state if this does prove to be the root cause I don’t think the L2 design will prove to be more vulnerable than most any other air rifle design out there? Static damage to any high pressure device or component is a very high possibility for any air rifle?

Certainly if you witness damage to a high pressure component or see any evidence of damage, stop and de-pressurize. Also be very aware of the fact sometimes there are no visible indications when there is actually some damage. These air rifles are not your father’s M1 Garand!

I see now that Ed has similar speculation with finite element analysis on post #128 with an impact to the butt. My example may actually take less force to cause the same moment due to the longer lever distance.


6A74BECE-8B3A-418C-ADC7-706666FBCC38.jpeg
 
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…a spacer between the bottle and plenum might prevent the above scenario…?
Tri-angling the support back to the front of the tube would basically eliminate the fulcrum and the moment force from either a butt or bottle vector force. Much more structure would be involved with any failure as compared to the point failure without this support. The rifle would also be more effective for use as a head butt or club? I’m curious if Ed has done a finite element analysis of an impact with his original tube reservoir and support in place? I bet it would nearly eliminate this issue?

”If Grandmother had nuts she would Grandfather” Putin

Yeah but if your Grandfather thought they were a Grandmother you probably would not exist to worry about it…
 
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To tell you truth I even cannot imagine that this O-ring can be installed on the wrong place!!! But, if we accept that as the version -- that is complete desaster! :) I assume that it was blown from it's place by the explosure, though how it remain unbroken that is another magic...
Ed, are the parts tracking successfully back to you? The OP has gone very quiet it seems 🤔
 
yep Bernie coming in to ALWAYS comment on this lol…

Ed, this comment is not directed at you, it’s because some people think that if you can go to a fire house for a fill in Russia, they can do it over here…

However, if you live in the US, owning an Airgun doesn’t entitle you to interrupt first responder operations. This is the type of behavior that reflects very poorly on the community as a whole, and looks super suspicious to anyone not familiar with PCPs. There’s a lot of talk about how to set a good example when it’s comes to safety, not bothering neighbors, etc. this is part of that. I’ll now step down from my soapbox.
 
yep Bernie coming in to ALWAYS comment on this lol…

Ed, this comment is not directed at you, it’s because some people think that if you can go to a fire house for a fill in Russia, they can do it over here…

However, if you live in the US, owning an Airgun doesn’t entitle you to interrupt first responder operations. This is the type of behavior that reflects very poorly on the community as a whole, and looks super suspicious to anyone not familiar with PCPs. There’s a lot of talk about how to set a good example when it’s comes to safety, not bothering neighbors, etc. this is part of that. I’ll now step down from my soapbox.
That’s one helluva soap box.
As a firefighter myself, I haven’t seen an issue with people coming in and asking for bottle fills. With our sport as small as it is, it’s not really an annoyance. I will say, if your bottles out of date, or isn't dot approved, we won’t fill it. This protects us from liability issues.