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