Editing Propellant (section)

===Compressed gas propellants===
In applications in which a large quantity of propellant is used, such as [[pressure washing]] and [[airbrush]]ing, [[air]] may be pressurized by a [[compressor]] and used immediately. Additionally, a hand pump to compress air can be used for its simplicity in low-tech applications such as [[Atomizer nozzle|atomizer]]s, plant misters and [[water rocket]]s. The simplest examples of such a system are [[squeeze bottle]]s for such liquids as ketchup and shampoo.

However, compressed gases are impractical as stored propellants if they do not liquify inside the storage container, because very high pressures are required in order to store any significant quantity of gas, and high-pressure [[gas cylinders]] and [[pressure regulators]] are expensive and heavy.