air treatment units(also called air preparation units) don’t work seperately, they’re auxillary components and mainly for treating air source from air compressor. There’re 3 different air treatment units for different function, air filter, air regulator and air lubricator. Air filter is for filtering the dirt and some big particles from air source, and after the filteration the air will be clean and dry. There’re different filteration degreee, some air filter has precision of 40 micron, while some other 25 micron or 5 micron. Air regulator is for regulating the pressure of the air source, can adjust air source from higher pressure or lower pressure to the pneumatic cylinder wated pressure. When the air source was filtered and regulated by the former two air treatment units, it becomes clean, dry and with stable pressure, still it needs oil lubrication by the air lubricator, in this way, the air source will be working more smooth and the valves and cylinders can also work more stably and long life cycles.