Paintball tanks typically mount on the rear of a paintball weapon.
Paintball tanks store the gases used to fire paintball guns. These tanks allow quick expansion of gas into the weapon in order to launch the paint-filled projectiles over a long range. Paintball centers offer a wide variety of tanks, each with its own advantages and disadvantages. Most paintball guns, known as markers, may use any of the three major paintball tank types.
Many of the earliest paintball markers used carbon dioxide in their primary tank. These canisters were very small and only lasted for a few-dozen rounds. Larger CO2 canisters developed along with more powerful paintball guns. Many paintball centers make CO2 fill stations available to paintball players, and the cost of this service is very low compared to nitrogen-filled tanks. Likewise, the carbon-dioxide tank costs less than most other forms of paintball tank. The liquid state of pressurized CO2 leads to its major drawback: Any liquid CO2 that escapes into the paintball gun will quickly damage its rubber rings or plastic firing mechanisms.
Nitrogen does not suffer the same problems as liquid CO2 due to its consistent gas state. Escaping gas does not damage the marker. Nitrogen is more expensive, however, and only available from large paintball centers and medical-supply groups. Nitrogen canisters come in a number of sizes, ranging from smaller 9-ounce containers to massive 20-ounce tanks. Large nitrogen bottles can hold refills for 100 or more tanks, making large-scale purchases economical for paintball teams and centers.
Compressed-air tanks use everyday air, in its native 80-percent nitrogen form, to power paintball markers. Air compressors offer the cheapest and most reliable source of refills for compressed-air tanks, though only commercial-grade compressors can fill the tanks to the necessary 2,000 or more PSI required for paintball guns. Many paintball centers purchase SCUBA tanks to refill these types of paintball tanks, and diving centers also offer inexpensive refills for players off site. Compressed-air tanks typically cost more than their counterparts due to the cost of materials needed for their solid construction.