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 flow, elements and rotors. … The component can be cooled by cooling drinking water that flows through unique pockets in the component Oil-free Screw Air Compressor casing.
In a lubricated screw compressor, the lubricant will come in direct in touch with the compressor inlet air and compressed air. … The oil contains anti-oxidants to attempt to reduce the break down of the lubrication 
properties due to internal conditions.