Air Bottle Charging

[wymberley]

Got my PCP a while back but Covid and my non-covid illness curtailed my activities. Oppo needed his bottle charging so went along with him and got mine done although it didn't really need it just yet. Now, I have to say that I don't know about these things so didn't quite know what to expect. My problem is is that I was a Trenchard Brat in airframe flavour which gave me an understanding that when charging nitrogen, oxygen, air or whatever, on aircraft, the required figure is what you stuffed in - not a tad more or less. In a later life, Team Lotus required the same consideration for their active suspension. On collection my bottle although not 'hot' was reasonably warm. Sufficiently so for me to order a couple of blanking caps so I could check the pressure before doing anything. 

Is 270 bar an acceptable level within plus/minus when charging a 300 bar PCP bottle? As said, I know not for this application but can't help thinking about the fact that the this PCP work and other shooting business is an add on to the firm's main thrust of diving.

[Mice!]

30 minutes ago, wymberley said:

Is 270 bar an acceptable level within plus/minus when charging a 300 bar PCP bottle? As said, I know not for this application but can't help thinking about the fact that the this PCP work and other shooting business is an add on to the firm's main thrust of diving.

Read about this happening a few times, was it done while you waited,  or did you go back to collect it another day?

Some places will cool them and top up others probably don't bother, I've never checked but I've only had one bottle done that I could check.

[Walker570]

My supplier always fills mine whilst submerged in water and I have never noticed any temperature.  I honestly don't know what pressure they put in.

Charge a fiver.

[Houseplant]

As a diver, I wouldn't be thrilled with a 270 bar fill in a 300 bar cylinder, but I would probably accept it, especially if I was in a rush to get the cylinder filled.

[Ultrastu]

As the air is compressed  it heats up (all that friction and energy imput etc ) the compressor wont compress air above 300 bar (its not capable /legal) 

So it stops at 300 .it then cools down after an hour or so ,depending on the air temp . And when you check it now reads 270 bar (presuming your gauge reads the same as the shops ) as said above a top up and cool down and top up again is the only way to achieve  near 300 bar ,probably not actually perfectly possible but 295 should be achievable .

[wymberley]

8 hours ago, Ultrastu said:

As the air is compressed  it heats up (all that friction and energy imput etc ) the compressor wont compress air above 300 bar (its not capable /legal) 

So it stops at 300 .it then cools down after an hour or so ,depending on the air temp . And when you check it now reads 270 bar (presuming your gauge reads the same as the shops ) as said above a top up and cool down and top up again is the only way to achieve  near 300 bar ,probably not actually perfectly possible but 295 should be achievable .

Have to say that I've always charged from 6000psi bottles (except for LOX). What do folk use for the periodic pressure test?

My bottle was put on 'charge' when we arrived. Oppo had a problem with his rifle so after a while while they were looking into this, my charging was stopped. Then later before we left it was given a final charge. I know that rifle mounted gauges may not be all that accurate, but mine and my bottle gauge had identical reading up to the 232 bar.

As I don't think (for other reasons) that I'll be going back, any comments re Crackshot at Heathfield, anyone, please?

[sportsbob]

I have noticed that several factory set compressors safety valve opens at 300 bar so they are set to shut of at somewhere in the region of 285 to 290 bar so once cooled 270 is common and the reality is you will be on average  3 -4 fills down when using a 7L cylinder.

[Mice!]

1 hour ago, wymberley said:

but mine and my bottle gauge had identical reading up to the 232 bar.

I wouldn't fill your gun to 232, even if it says you can, I only ever go just over the 200 on my R10.

[oldypigeonpopper]

Hello, if you getting a 300 bar air cylinder filled then that is what it should be, anything less your getting short changed, just to clarify is your air cylinder 300 bar or 232 bar , ??  All the PCPs I have used I filled 5 Bar below the recommended manufacturers maximum Bar, eg AA 410 190 Bar, filled to 185 bar, filling a PCP will loose a small percentage of air with every fill, my first air cylinder many many years ago was a 12 ltr 232 bar , it just means you will not get as many fills , my first PCP was a falcon prairie when falcon engineers were still working within the Air Arms factory, 

Edited August 10, 2022 by oldypigeonpopper

[oldypigeonpopper]

23 minutes ago, oldypigeonpopper said:

Hello, if you getting a 300 bar air cylinder filled then that is what it should be, anything less your getting short changed, just to clarify is your air cylinder 300 bar or 232 bar , ??  All the PCPs I have used I filled 5 Bar below the recommended manufacturers maximum Bar, eg AA 410 190 Bar, filled to 185 bar, filling a PCP will loose a small percentage of air with every fill, my first air cylinder many many years ago was a 12 ltr 232 bar , it just means you will not get as many fills , my first PCP was a falcon prairie when falcon engineers were still working within the Air Arms factory, 

Hello, just to add it's very easy to check on how much air is in a cylinder after a few fills of a PCP, best fitting do an inline plug kit , for a few £s it's worth getting, at least to check if you got your cylinder filled and found less air than the recommended fill, 

[wymberley]

1 hour ago, Mice! said:

I wouldn't fill your gun to 232, even if it says you can, I only ever go just over the 200 on my R10.

This was going to be my next query as I have the R-10. I think I've read something about this - not sure -  regulator associated? If you take a small bucket to the well you will get the same amount of water as if you take a big one - you just have to go more often - no problem, easy enough. Also a car will last longer if you don't continually drive it a max revs - no problem. What is the reason for the 200 bar, please?

[Ultrastu]

The reg doesn't perform well much above 200 bar usually  ,(obviously there will be exceptions )

[Mice!]

50 minutes ago, wymberley said:

What is the reason for the 200 bar, please?

I'll have read it somewhere,  the Orings can blow and often when people have been having problems they'll have been filling to the max.

So I just stick to the 200, it still gives me way more shots than I need.

[wymberley]

2 hours ago, Mice! said:

I'll have read it somewhere,  the Orings can blow and often when people have been having problems they'll have been filling to the max.

So I just stick to the 200, it still gives me way more shots than I need.

I hope you’re right, Granddaughter is about to have a R-10 and Alecto afternoon and she’ll be moving lead around.