The MK-25 unit is a compressor and an expander coupled to a common drive shaft intent to create conditioned air without the use of refrigerants. This unit is very compact and most suitable for breathing air systems.
It is “oil free” in the respect that lubrication oil is prevented from entering the process air in the machine. The design features oil lubricated rolling element bearings and gear wheels as well as dry type labyrinth shaft seals. A controlled leakage of process air into the oil circuit and out to atmosphere is designed in the machine in order to prevent oil from entering the process air.