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View Full Version : why not CO2, what's the difference?



justinellery
12-17-2001, 08:06 PM
I have always run my RT pro on compressed air but the other day the field I play at ran out of compressed air. What is the difference between the classics and RT's making it where you can not use CO2? What would happen if I did? Anyone ever try it, did it work?:D

a_malfunction
12-17-2001, 08:15 PM
The reg recharges faster than CO2 can change from liquid to a gas. It will freeze everything up and it won't work.

justinellery
12-17-2001, 08:37 PM
have you tried it before though, how fast did it freeze up. I live in Florida and in the summer RARELY see a gun freeze up.

Butterfingers
12-17-2001, 09:42 PM
As Tom Kaye once described it:

You have a pitcher of water (air source) and you are trying to fill a cup (valve chamber).

The regular valve is like pouring water into the cup then slowing down near the end to make sure you dont spill any. Pressure is equalized before the chamber is full.

The RT valve attempts to dump the whole pitcher into the cup then worries about spills later. Any excess water spilled is equalized after it fills the chamber not before.

Now if you have co2 and happen to get liquid into the valve it is like dumping water into the cup, having it equalize, then after it is equalized the water in the cup starts expanding causing a spill. This will create DRASTIC velocity spikes. And will cause the blow off valve in the mag to vent.

Compressed air is always a gas so this scenario dosent happen. Thats why mag RT's are compressed air only.

ThePatriot
12-17-2001, 10:54 PM
Hey justinellery, where in FL?? yea yea im not gonna PM im to lazy

toymyster
12-18-2001, 04:22 AM
My buddy sold his RT to some kid, who proceeded to gas up his RT with CO2, he froze just about every O-ring in the thing!!! Remeber, if it says HPA only, it means exactly that!!!

Thordic
12-18-2001, 08:27 AM
Also, I believe Rob was the one who said that the on/off orings arent teflon in an RT valve. The only reason they use telfon orings in a stock on/off is because they are less prone to freezing. So the orings themselves in an RT are more prone to freezing, not just the fact that the valve design isn't made for it.

If you just needed to gas up your gun to check a trigger, or to fire off a few test shots at a VERY low BPS, you could PROBABLY get away with CO2 if you had nothing else available, but why bother? You may get away with it, but you have a pretty good chance of freezing up your gun, leaking while you curse and unscrew the tank, and then getting your air tank filled anyway.

As for actually PLAYING with an RT valve on CO2, forget it. The second you fire at a normal ROF, say goodbye to your ability to seal :)

mykroft
12-18-2001, 10:14 AM
The problem with CO2 is that it becomes liquid and cools down when compressed, thus feeding either sub-zero gas or liquid into your gun, and freezing stuff. The expansion chamber allows the liquid to become gas, and warm up before it gets to the gun. HPA/N2 is still gaseous under pressure, and doesn't cool off when compressed (It actually gets warmer from friction), so it won't freeze your gun, and as it's always gas, has less impurities, and must be regulated (CO2 is at 800-900psi in the tank, HPA is 3000psi or more), you get a much more consistent input to the gun, and therefore a more consistent gun.

The downside to HPA, is the volumetric efficiency, you need more gas for a given amount of shots. Thus the requirement to run much higher pressures in the tanks.

Butterfingers
12-19-2001, 09:00 AM
co2 cools down when it expands.

Its called a phase change and it is endothermic. Freezing occours when you get liquid in the valve , it expands absorbing thermal energy freezing youre valve.