The piston compressor has been around the longest but is still a popular choice. The piston compressor works by the piston moving forward in a cylinder by way of a connecting rod and crankshaft. There are two ways of using a piston compressor; if just one side of the piston is used for compression, it is known as single acting. If both the top and bottom sides of the piston are used, this is double acting.
The piston compressor is capable of compressing both air and gas with only slight alterations. It is the only compressor that is accomplished at compressing gas and air to high pressures, for equipment such as breathing equipment.
The screw compressor is the most prevalent compressor in use today. The rotary screw consists of male and female rotors which move towards each other, decreasing the volume and the housing between them. The length and shape of the screw determine the pressure of the screw as well as the form of the discharge point. The rotary screw is able to work at high shaft speed and combine a sizeable flow rate with small exterior dimensions. They are suitable for pharmaceutical and food and beverage manufacturing, among others.
The rotary vane is the undisputed most reliable air compressor on the market today. It is driven directly, at extremely low speed. The rotor moves constantly and comprises of sliding vanes which move along on a film of oil. These vanes slot into grooves on the rotor. Pressurized oil injection controls the heat which is generated through air compression. Rotary vane air compressors are used for dentistry, printing and packaging.