I put a regulator in my S410E awhile ago and started charging it to 250 bar for the extra shot capacity. Well, today while charging it spit out an o-ring near the fill port. I guess you can see why. Oh well, maybe I can turn it into a blunderbuss.
Air Arms Why you shouldn’t overpressurize your S4xx/5xx
- Thread starter Sawney Bean
- Start date
No one was hurt. It was actually not that eventful. The gun was on the pump and suddenly there was a large hissing noise and air was visibly blowing out from the underside of the gun. I should have had the foresight to take a picture of it, but it looked as normal, only with a chunk of o-ring extruded between the reservoir and the end cap.
I had started charging it to 250 bar because I had read online that the Air Arms reservoir tubes were rated to 300 bar. With the regulator set at 150 bar I assumed that 250 would be a safe fill.
I had started charging it to 250 bar because I had read online that the Air Arms reservoir tubes were rated to 300 bar. With the regulator set at 150 bar I assumed that 250 would be a safe fill.
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Guess you can't believe everything you read on line. Maybe the tube is rated to 300 bar UNTIL you put threads in the end. Honestly this borders on "dangerous and unsafe" practices.
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I think that’s exactly the situation. It’s not the threads so much as the o-ring mating surface, which is even thinner than the area around the threads.
Regarding the dangerous and unsafe practices, that’s exactly why I posted it, in order to discourage anyone else from doing the same thing.
Edit: there is a airgun YouTuber advocating 250+ bar fills.
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My neighbor thought he could do that to his s510 after he regulated it and I advised him STRONGLY to stop...I didn't even wanna be in the same room as that gun when he filled it so high....looks like I was right.
He got his advice online, I won't name names but I think some youtuber...
-Matt
He got his advice online, I won't name names but I think some youtuber...
-Matt
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Crazy how youtube personalities can make so many false, damaging statements through-out their career with little repercussion, yet he's consider one of the big wigs in the industry. NAME AND SHAME.
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I intend on messaging him and letting him know about my own experience. I’m not going to try and call someone out over something I was all too willing to do myself without first giving them the chance to retract it.
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It's all good, I know who and my hint above and yours should make it obvious to anyone else keen enough.
-Matt
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In case you didn't know. You can get a replacement here.
Air Arms Air Cylinder for S400/S410/S500/S510 Carbines | Pyramyd AIR
We've got a great price on Air Arms Air Cylinder for S400/S410/S500/S510 Carbines at Pyramyd AIR. Shop where the experts do!
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I got the last one they had in stock.In case you didn't know. You can get a replacement here.
Air Arms Air Cylinder for S400/S410/S500/S510 Carbines | Pyramyd AIR
We've got a great price on Air Arms Air Cylinder for S400/S410/S500/S510 Carbines at Pyramyd AIR. Shop where the experts do!www.pyramydair.com
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Well, if you get real unlucky, both your fill gauge, and your reservoir gauge are reading low.... This is why I invested in a very good gauge for my 9 litre fill tank.
I can also see why it was weak... a lot of my guns have the oring on the other side of the threads (inside) where the tube is the thickest
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I'm glad you didn't get hurt.
It kind of worries me that this was only a 20% overfill. Now I'm not saying that isn't a lot, but on the other hand, I'd like to think they are burst tested a bit higher than 20% over. Heck, I've seen a lot of gauges on airguns that were 20 bar off..... Pays to be careful! I used to work with HPA cylinders a lot, and I'm thinking 4500 CF tanks are tested to something on the order of 7Kpsi, and were tested to have a burst of something on the order of 17,000psi, but that's from memory, it's been a few lifetimes ago. It runs in my mind 1.7x working pressure is your test pressure.
It kind of worries me that this was only a 20% overfill. Now I'm not saying that isn't a lot, but on the other hand, I'd like to think they are burst tested a bit higher than 20% over. Heck, I've seen a lot of gauges on airguns that were 20 bar off..... Pays to be careful! I used to work with HPA cylinders a lot, and I'm thinking 4500 CF tanks are tested to something on the order of 7Kpsi, and were tested to have a burst of something on the order of 17,000psi, but that's from memory, it's been a few lifetimes ago. It runs in my mind 1.7x working pressure is your test pressure.
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250 bar is 30% over the recommended 190 bar IIRC. Although I'll agree failure shouldn't really occur here, but this is why you don't overfill...
-Matt
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I'm quite glad you were not injured.
I've had several AA rifles over the years and it REALLY surprises me that this is not more common. I really do not consider AA' s poorly made... actually could be a favorite except for the air tube sealing. If you look carefully, you'll see that they took a 9k psi tube (a guess here but it appears to be), and reduced the thickness at the seal by a significant margin, and also cut threads inside the pressurized portion of the tube... Both will SIGNIFICANTLY reduce the burst or rupture pressure in those spots.
All other air rifles I own have the seal INSIDE the threaded portion where the tube is full strength. The only tradeoff I can think of is having the seal survive the assembly process on others like Daystate but that usually isn't a problem.
Again... not hating on AA... just don't understand this from an engineering or liability view.
Just be very careful to not overpressure in the future when you get it repaired.
Bob
I've had several AA rifles over the years and it REALLY surprises me that this is not more common. I really do not consider AA' s poorly made... actually could be a favorite except for the air tube sealing. If you look carefully, you'll see that they took a 9k psi tube (a guess here but it appears to be), and reduced the thickness at the seal by a significant margin, and also cut threads inside the pressurized portion of the tube... Both will SIGNIFICANTLY reduce the burst or rupture pressure in those spots.
All other air rifles I own have the seal INSIDE the threaded portion where the tube is full strength. The only tradeoff I can think of is having the seal survive the assembly process on others like Daystate but that usually isn't a problem.
Again... not hating on AA... just don't understand this from an engineering or liability view.
Just be very careful to not overpressure in the future when you get it repaired.
Bob
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