Air pump

[1] The device that supplies the fresh air needed by the air injection system.
[2] A reciprocating or centrifugal pump used to remove air, and sometimes the condensate, from the condenser of a steam plant.
See also air ejector
[3] Any device used for transferring air from one place to another. A compressor increases the pressure, a vacuum pump reduces the pressure and a blower causes a rapidly moving air blast .,