Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
compressed air
Introduction References & Edit History Related Topics
Images
compressed air and decompressed air
Quick Facts
Related Topics:
pneumatic device
air
See all related content
Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
compressed air and decompressed air
compressed air and decompressed air This schematic of a piston and cylinder pump illustrates the relationship between gas molecules and pressure. When the piston is pushed into the cylinder, the air inside the cylinder becomes compressed. In this state, the gas molecules are close together and pressure within the cylinder is increased. When the plunger is pulled, the air inside the cylinder becomes decompressed. Thus, the gas molecules are farther apart than in the compressed state, and pressure within the piston chamber is reduced.

compressed air

technology
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
Last updated
•History

News •

Brabazon Launches Free Compressed Air and Pump Calculator Tools for Midwest Manufacturers • Oct. 21, 2026, 3:49 PM ET (Rochester Democrat and Chronicle)

compressed air, air reduced in volume and held under pressure. Force from compressed air is used to operate numerous tools and instruments, including rock drills, train brake systems, riveters, forging presses, paint sprayers, and atomizers. Bellows have been used since the Early Bronze age to provide air for smelting and forging. The 20th century witnessed a large increase in the use of compressed-air devices. The introduction of jet engines for military and passenger aircraft stimulated the use and improvement of centrifugal and axial-flow compressors. Digital-logic pneumatic-control components (developed in the 1960s) can be used in power and control systems (see pneumatic device).

This article was most recently revised and updated by Kara Rogers.