Pneumatics is the discipline that deals with mechanical properties of gases such as pressure and density, and applies the principles to use compressed gas as a source of power to solve engineering problems. The most widely used compressed gas is air, and thus its use has become synonymous with the term pneumatics. Hydraulics is the discipline that deals with the mechanical properties of liquids, and applies the principles to solve engineering problems. Gases and liquids are both fluids as opposed to solids. Pneumatics and hydraulics are similar in many respects and often described by the generic term fluid power.

The use of air as an energy transfer medium can be traced back more than 2000 years, and the varying areas of application reflect the changes in technology since then. The industrial use on a larger scale began 1888 when a 1,500 kW central compressor station was installed in Paris to supply the city with compressed air (Neermann 1989). With the evolution of electric power, this form of energy transfer became obsolete, but the competition between fluid power systems and electric systems is still going on.

Around 1900 the most often used pneumatic components were pneumatic hammers, e.g. in ship yards. As technology evolved, riveting has been replaced by welding and pneumatic hammers are now used mostly on construction sites. Industrial application of pneumatics for automation started around 1950 when the demand for automation in industrial production lines increased and suitable elastomeric materials for valve and piston seals became available.

Many...