The piston compressor is one of the earliest compressor designs, but it remains the most versatile and is still a very efficient compressor. The piston compressor moves a piston forward in a cylinder via a connecting rod and crankshaft. If only one side of the piston is used for compression, it is described as single acting. If both sides of the piston, top and underside are employed, it is double acting.
The versatility of the piston compressors knows virtually no limits. It compresses both air and gasses with very little alterations. The piston compressor is the only design capable of compressing air and gas to high pressures, such as breathing air applications.
The configuration of a piston compressor can be a single cylinder for low pressure/low volume to a multi-stage configuration capable of compressing to a very high pressure. In these compressors, air is compressed in stages, increasing the pressure before entering into the next stage to compress the air into even higher pressure.