The oil-free screw compressor element
No oil implies that there is absolutely no essential oil for sealing the rotors and for cooling the compressed air, components and rotors. … The element is cooled by cooling Oil-free Screw Air Compressor drinking water that flows through unique pockets in the element casing.
In a lubricated screw compressor, the lubricant will come in direct in touch with the compressor inlet air and compressed air. … The essential oil contains anti-oxidants to try to reduce the break 
down of the lubrication properties because of internal conditions.