To power a paintball marker, you can choose between CO2 or high pressure air, and most players choose CO2 as these are the cheapest tanks to buy. While most paintball guns can use CO2 or compressed air, more expensive tournament-style markers must use high-pressure air, as CO2 can damage these guns. While ultimately cheaper, CO2 can be hard on any paintball gun due to its nature. Compared to compressed air, CO2 is more volatile as it converts from a gas to a liquid (and vice versa) as it is used in small spurts each time you pull the trigger on your gun. CO2 is also greatly affected by changes in temperature. A properly filled CO2 tank will have an internal pressure of approximately 850 pounds per square inch (psi) at temperatures of 70 degrees (F). A one degree rise in temperature will cause the pressure in your tank to increase by 11 psi.

This means that the temperature of your playing environment or storage area can affect the performance of your CO2 marker. If you’re playing in a 70 degree or so environment, when the hot afternoon temp hits, your tank pressure can build over 400 psi pretty quickly. Without a regulator, this will often cause your gun to run hot, possibly even dangerously high. In most cases, CO2 tanks will not overheat while in use. Leaving them out in the sun or in your car while you eat lunch on a summer day is often how this happens. If a CO2 tank overheats, it has a special mechanism (called a “bursting disk”) that will prevent it from causing a dangerous explosion.

The rupture disc is a safety pressure relief valve that will rupture if a CO2 tank builds up too much pressure from getting too hot. The result is a spray of CO2 vapor that can cause the tank to spin a bit until enough pressure is released. If this happens, it is best to get away from it and wait for it to empty or at least stop making hissing noises; after which, the tank is safe to drive again. At this point you can take the tank to any airman at a paintball shop or commercial air tank supply company. The rupture disc is replaceable and he can set it to the proper torque, however this is something a professional aviator should handle to make sure it’s done correctly. If you can’t find a professional airman it may be easier to just buy a new CO2 tank as they are cheap and easy to find.

Compressed air is the other most common power source used for paintball guns. Compressed air tanks are more expensive than CO2 tanks, however they perform much more consistently. They have built in regulators that reduce the pressure of the air supplied to the paintball gun to keep it below 800 psi. Most high pressure air tanks for paintball markers range between 3,000 and 5,000 psi. When using high pressure air tanks, it is important to read and follow all manufacturer’s instructions regarding use and storage. Unlike CO2, compressed air is not as sensitive to temperature gradients; this is the main reason why they perform more consistently on the paintball field and are not as volatile to heat. If the rupture disc ruptures or a component is leaking in a compressed air system, follow the same protocol as with the damaged CO2 tank. The best thing to do is walk away from it and wait for it to drain before taking it to a professional for inspection/repair. High pressure air leaking from a broken manometer can cause serious injury by injecting air under the skin if a body part is held to the side.

All compact CO2 and high pressure air tanks used for paintball guns have a limited lifespan. CO2 and air tanks have an expiration date stamped on them, usually 3-5 years from the time of purchase. After that, the tanks must be tested and recertified by a hydrostatic testing facility before they are deemed safe for further use. Unfortunately, the cost of testing/recertification usually exceeds the cost of a new tank, so most players simply opt to buy a new one. It is advisable to regularly inspect the air tanks before each game. Check for leaks, dents, damage, or other questionable signs of wear. Also check the tank valve or regulator to make sure it is not loose in the tank. Never remove or attempt to install the CO2 tank valves; this should only be done by a professional who has been trained in the maintenance of high pressure compressed gas equipment. As a general rule, if your tank is leaking, stay away from it until it is empty; then take it to a professional for repair or just buy a new one. If you are ever in doubt, do not hesitate to contact the manufacturer or distributor of the product for advice.