Reciprocating piston compressors are available as Single Stage or Two Stage units. In Single Stage, the air is drawn into a cyclinder and compressed in a single piston stroke and can reach pressures of up to 150 PSI.
Two stage compressors compress air in two steps. In the first step, air is compressed to a certain level then transferred to another chamber and compressed again to its final PSI. In the process of transfer to the second chamber the air is often cooled through an intercooler. This makes it possible to achieve higher pressures, commonly up to 200 PSI.
Cylinder lubrication is related to the type and pressure of the gas being compressed. In some cases the frame bearings and cylinder use the same oil for lubrication, but in higher pressure and temperature applications a synthetic oil of higher viscosity might be used to lubricate the cylinders.