Paintball Air Systems. Paintball Compressed Air Tanks and Systems
A paintball gun relies on a bottle of compressed gas to operate. The term paintball air systems actually covers two types of gas. They are CO2 (carbon dioxide) and HPA (high pressure air).
Carbon Dioxide - When compressed CO2 turns into a liquid. Therefore, it has to expand back into a gas to power the paintball marker. The expansion into gas requires heat energy to be added. The heat is taken from the tank which cools in the process. For casual use this is not a problem but in cold conditions, under continued fire, the tank can form ice on the outside. Should the liquid CO2 get into the paintball gun it can damage the O-rings and generally jam the marker putting it out of commission for quite a while.
If the CO2 tank is kept upright the gas will rise to the top next to the valve. To help keep the valve from sucking liquid anti-siphon tubes are used to extend the mouth of the valve. Horizontal tanks use an ASA (air source adapter) to keep the gaseous CO2 near the valve.
Liquid CO2 takes time to heat up and evaporate. During a rapid volley of shots the available gas can deplete leaving the paintball gun short on power. This can cause large variations in range and accuracy.
HPA or N2 - An alternate power source is high pressure air (HPA) or nitrogen (N2). HPA or nitrogen when compressed remain as gasses. The tanks will still cool when the gas expands but to a much lesser degree since it does not require extra heat to change from a liquid to a gas. Not having to change state means that pressure variations are minimal and range and accuracy can be maintained under the most severe rapid firing sequences.
However, HPA and N2 are stored at at much higher pressures than CO2 - 5,000 PSI vs 1,200 PSI. This means that the tanks are higher tech and heavier, making them much more expensive.
In most instances the HPA and nitrogen are interchangeable. "Air" tanks can either be filled with pure nitrogen or air which is 79% nitrogen. However, it is important to check with the manufacturer of the tank to be certain what the filling requirements are.
HPA tanks can often be filled from SCUBA tanks reducing the cost significantly. Again check the manufacturer instructions.
Propane - A rather obscure propellant, Tippmann designed it's model C3 for use with propane. The main advantage of propane was the number of shots that could be fired on one tank of gas. It also helped that the gas was at a much lower pressure. Apparently, up to 50,000 shots could be fired on one 16 ounce tank.
Conclusion - Nitrogen has become the gas of choice for several reasons.
(1) Liquid CO2 can leak into the paintball gun if the tank is not fitted with an anti-siphon tube, or a regulator or expansion chamber. This can cause damage to the marker O-rings. Nitrogen, because it does not liquefy, does not have this problem.
(2) Because the delivery pressure can be maintained at a more constant level, nitrogen powered guns shoot with more consistency.
(3) Nitrogen is cheaper to refill than CO2 at approximately $3 to $5 a tank.
The only real negative with nitrogen is the cost of the tank. CO2 tanks are much cheaper.
Paintball air systems are what ultimately drive the sport of paintball. Because of the high pressures involved paintball compressed air tanks must be handled with care and maintained properly to ensure safe and trouble free operations.
