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If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 3:33 am
by gigitt
A friend asked me why cant you get some other cheap gas like co2 from BOC and fill up with that!
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 6:53 am
by GriMo
Id say it largely comes down to operating pressures, and densities. Not sure exactly but i would imagine the valves etc within are all designed to work with the expansion rates of normal air. Not sure what effect a denser or less dense Gas could have, issues with corrosiveness and temperature sensitive aswell i guess.
Not really sure but i would imagine Lewis harry or NH will be along in due course
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 7:29 am
by ogre6br
sorry mate
but
Is $7 for a 12 litre 300 BAR scuba tank fill to expensive??
I'd prefer to pay $7 for a fill of the propper clean dry air rather than many hundreds if not thousands of $ for a repaired or new PCP
Just asking???
P
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 11:02 am
by gigitt
Dont have a bottle... yet only Hand Pump
Rapid need 3200psi
I did ask my friend about a getting an out of hydro test date scuba tank and he said you will not be able to fill it in Sydney!
His Dad used to work in the Hospitals and they have tanks of various gases all at high pressure.
The question was asked to me, can I use other inert gasses like co2 or o2 etc
We figured that both these gases are the major components of our AIR so damaging internal PCP components will be zip.
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 11:20 am
by GriMo
well, o2 definitely wouldnt be my recommendation. The stuff tends to make burning pretty emphatic.... high pressure, source of fuel (little bit of crease/wax etc).
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 11:31 am
by andrewk
O2 isn't an inert gas either from what i can remember
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 11:59 am
by RayG
gigitt wrote:A friend asked me why cant you get some other cheap gas like co2 from BOC and fill up with that!
It has all been tried before G, and some of the outcomes are and can be horrific.
One nut in UK used Oxygen in a Rapid and it practically dissolved the action block and the air cylinder Vaporised.
With all of the good PCP makers the gun actions and cylinders are made for high pressure air only mate.
The yanks do make a couple of guns which can use either air or C02 but they are rare,then there are guns also dedicated to CO2 only.
Buy a Dive tank mate and have fun safely.
Cheers Ray.
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 12:20 pm
by gigitt
Just wanted to know the what if... I will update my friend that he should not keep sugesting things that might blow my head off!
I know ultimately I will have to go a dive tank... and then even one of Lewis Compressors
Cheers boys.
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 1:16 pm
by daisy
I have heard of people in the USA using nitrogen. A bit expensive to set up.
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 1:41 pm
by kjd
daisy wrote:I have heard of people in the USA using nitrogen. A bit expensive to set up.
Really what would be the difference between nitrogen and air if Air is 70% nitrogen?
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 4:47 pm
by Rumpus
Nitrogen is more stable in changing conditions.. Air will change depending on humidity, temperature. It can contain moisture depending on the system used to fill the cylinder and the pickup etc.
Air is made up of Nitrogen 78% Oxygen 21% and 1% other Gases..
Nitrogen I would imagine would give a more consistent results and will be better for the firearm as there will not be the moisture content thus why it is also used in rifle scopes and similar gear...
Mind you I have no experience with Air guns, but have a fai mr amount of experience with Oxygen and Air Cylinders..
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 5:02 pm
by RayG
By what I have learnt about Nitrogen from the USA AG forums is that the airgunners were getting big changes in POI when at altitude in the mountains. The experiments with Nitrogen apparently were in part successful but it never really took off.
R.
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 5:42 pm
by Rumpus
Yea, that would make sense as as altitude increases pressure decreases so Air would work better as it will also change whereas nitrogen will remain a constant so different external pressures will shoot differently..
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 9:25 pm
by stillair1
Fill it with air and nothing else. There was a muppet over here that filled his rapid with oxygen. Anyway it exploded while in use as anyone in the compressed gas business will tell you oil residues and compressed 02 are a bomb waiting. The result explosion blew out the doors windows and lifted the roof of an MOD building. The operator suffered bad facial burns.
I have seen the particular rifle and pics, the stainless bit between the action and bottle was never found.
http://www.airgunbbs.com/forums/showthread.php?t=38213
.
neil
Re: If you could, What CAN you fill a PCP with other than air?
Posted: Wed Sep 30, 2009 9:38 pm
by Marco
guys how about helium and humans can also breath it underwater
its also safe for balloons and KIDS and easlly available from BOC gases.