Over filling cylinder

[gunsmoke77802]

So when I fill my cylinder to 200bar and come back the next day I'm down 20-25bar. I know the physics. Would it hurt to go over that much to get a full fill or am I being nit picky. Reason I ask is when I'm still in the green on the low side saying I have enough air my pellets start cutting ugly holes

[marky-d]

Realistically, it would most likely never be a problem. However, the better/safer option would be to fill to 200bar, let it cool, then top it off.

marky-d

[Gwhite]

If you like tidy holes, make sure you are using good targets. These are FAR better than any US made targets:

https://www.krugerpremiumtargets.com/or ... ock-of-250

Also, the gauges on most cylinders are not very accurate, and depending on the brand, the "green" region may be overly optimistic. You should be able to get good shots down to around 70-80 Bar. If that doesn't work, your regulator may be mis-adjusted.

[David M]

So when I fill my cylinder to 200bar and come back the next day I'm down 20-25bar.

When you say cylinder are you referring to the pistol cylinder or the big dive tank cylinder ?
I fill a dive tank on a compressor (without the bottle sitting in a water tank), so the tank gets hot.
I fill it to 210 bar.
After an hour or two when it cools back to room temperature it is at 200 bar.
Filling the pistol cylinder from it after it is cool the pistol cylinder has a very slight temp rise than
dissipates quickly, leaving it on the big cylinder for a minute or two it cools and takes on bottle pressure.

[gunsmoke77802]

Yeah pistol cylinder. Didn't think about leaving it on tank to normalize. Good idea

[Ramon OP]

Do you have access to the filling station? Then you are being nitty picky :) If you rarely have access to it then buy a pump and fill your pistol cilinders to about 150: good for more than a 120 shot training session (unless you've increased the speed of your shots) and easier than exerting yourself to 200 for nothing (the last 50 bars with my pump are a pain). There's absolutely no advantage in shooting to have the cylinder up to 200. I just refill after training sessions.

[m1963]

We routinely allow cylinders to normalize when attached to tanks. It makes good sense. Why overfill? We encourage all of our shooters to follow safe practice when handling compressed air.

[Arcturus]

Never ever try to overfill the air cylinder. Never ever.

https://timesofindia.indiatimes.com/spo ... s?from=mdr

[David M]

I don't know that it was overfilled.
Look at the photo with the end caps in his hand, the gauge shows just under 200 bar.
That assumes that the gauge was damaged and jammed when it blew.
Also the tube failure seems to be very straight along the cylinder length and very nearly at 180 deg apart.
Appears to have failed along a extrusion line.
Makes me wonder how the tube was made and what sort of die it was forced into to extrude.

[m1963]

David M, you are spot on. Was this cylinder even legitimately produced? Who knows?

[PeeWeeDaddy]

Did you guys read the accompanying news article?
The link in the story.
Scary.

[Gwhite]

Hopefully more details will come out in time. The text on the cylinder and the logo on the pressure gauge look a lot like it was a Morini.

The local SCUBA shop thinks they are doing us a favor by filling our tanks to 230 Bar. We have a hard time convincing them to ONLY fill our tanks to 200 bar. That's all our various pistol cylinders are rated for, and with students filling their cylinders, we don't want any possibility of a problem. We use high quality large gauges from Best Fittings on our fill adapters, so we can monitor the cylinder pressure accurately, independent of the built-in gauges.

When we put a new tank into service, I won't let the students near it until I'm sure it's down to 200 bar. I frequently fill a whole bunch of cylinders CAREFULLY to 200 bar until the tank pressure is down to a safe level. We had to put a new tank into service right before a big match last month, and I had to just vent the top 30 bar because there wasn't time to fill a bunch of cylinders carefully.

[kqrxbn]

That's a nasty accident! My Steyr cylinders have two numbers on them: "PW 200 bar" and "PH 300 bar". I interpret the first number as something like "working pressure" and the other what they've tested it at. I usually fill the cylinder to a couple of strokes beyond 200 bar because when it is unscrewed, it drops a little bit. Will keep these images in mind next time

[KDZ]

A cylinder could also fail/rupture at or below nominal max pressure. What about putting the cylinder into a heavy steel pipe (say 1/4" wall thickness) and then filling? At least in this case shrapnel would only fly out of the sides of the pipe and you could stay safe(r) by keeping away from the pipe ends.

[David M]

The only time overfilling is a problem is if you are filling a 200 bar tank from a 300 bar cylinder.
This cannot be done with the standard fittings because the 200 bar adaptor will not fit a 300 bar
cylinder, it leaks because it it shorter.
You cannot overfill a 200 bar tank from a 200 bar cylinder.
Most pistol tanks are proof tested to 150% of operating pressure.
There was something very mechanically wrong with that tank, lets wait for the engineering report.

[Gwhite]

I believe you can buy "adapters plugs" that allow you to bypass the deeper thread safety feature. Their mere existence strikes me as an accident waiting to happen.

[David M]

Yes, you can or you can lathe turn a adaptor....or just blow yourself up.
If used as designed everthing is fine, but sometimes you just cannot train Pelicans....

[PeeWeeDaddy]

We have a couple of fellows shooting 10M here in the SF Bay Area with those type of cylinders.
I will not be shooting next to them.

[David M]

Don't jump the gun, these pistol have been safely in use since 1992 with no problem.
Wait for the engineering report or recall before you condem them.
Just take care for now.

[gn303]

Overfilling the cylinder looks like a bad idea. I have a cylinder that after a while runs completely empty. I figure it has to do with the valve. But 'overfilling' it makes no sense and as Arcturus suggests may be dangerous. Remember you're putting other people at risk as well.
Save shooting!