What is Compressed air?
[[File:0-4-0-engine.JPG|thumb|A railway [[locomotive]] powered by compressed air. This was used in the [[mining]] industry]] '''Compressed air''' is [[air]] stored under a [[pressure]] that is greater than [[atmospheric pressure]]. It is generally produced by an [[air compressor]]. ==Uses== Compressed air may be used for transfer of [[energy]] in industrial processes. Compressed air is used to power [[pneumatic]] tools. Compressed air is used to spray [[paint]], to operate air cylinders for automation, and to propel vehicles. [[Railway brake]]s applied by compressed air make train travel safer. Compressed air brakes are also found on large road vehicles, such as [[truck]]s and [[bus]]es. [[Category:Mechanics]]