The oil-free screw compressor element
No oil implies that there is absolutely no essential oil for sealing the Oil-free Screw Air Compressor china rotors and for cooling the compressed atmosphere, components and rotors. … The component is cooled by cooling drinking water that flows through special 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 oil contains anti-oxidants to attempt to reduce the break down of the 
lubrication properties because of internal conditions.