Nitrogen

[stillair1 16]

Stick to clean compressed air, industrial gases have various grades and the cheap ones will contain dust, which will muller seals.

[DIVERD 34]

We should always use clean comp. air in our pcp's However for the purposes of discussion:

 

Other basically inert gases will have different properties and will certainly effect the way a pcp operates. CO2 is ok but very temperature dependant, much more so than other gases because of the way it is stored. It boils off from liquid to gas to produce the pressure and this rate of boiling depends on ambient temperature.

 

Gases such as Argon, have larger molecules and are heavier than air, when breathed as argonox make you sound like Barry white as they move more slowly through the voice box. They would certainly reduce the velocity of a pellet from an air gun.

 

Hydrogem would just blow up like hindenburg

 

Helium is a small light fast inert gas. it moves quickly through the voice box making a donald duck squeeky voice. It would have the opposite effect to argon and would produce a far faster pellet than both air/nitrogen and argon. It is a leaky gas as it is so small so would probably quickly leak from a rifle over a week or so. FPS increase of up to a 1/3 more when compared to air have been found in my application, and a similar effect would be found in a PCP. However this would push a rifle considerably above the 12ft/lb and therefore should never be played with. Also, because although the gas will have been changed the rifle seals would not, and it may burst or displace these, as the pressure may not have changed but the speed at which the pressure is applied will and most seals have operating ranges for taking up this strain.

Edited November 29, 2009 by DIVERD

[hughes_jh 0]

DIVERD, well done on the informed answers. I'm totally in agreement that we should only use compressed air (well, I have to as I use a pump!) but the incessant argument that every gas other than compressed air is dangerous doesn't wash with me, I'm an engineer and know of countless uses for compressed gases (other than air) where they ensure safer working conditions or they are used in much more dangerous conditions than our little 12 ft lbs air rifle can accomodate e.g. Argon shields in holding furnaces, Nitrogen in laser cutting, Argon in MIG welding.

 

Phantom, thats also a great point about alternative gases unpredictably tipping the power rating over the 12 ft lbs limit.

 

Finally, the example of using oxygen and acetylene are just cringe-ing-ly horrible. It makes you laugh at first, then think how horrific it would be in reality... no laughing matter really.