FS-Curtis, W-Series Oil Free Air Compressor is 100% oil free compressor. The W-Series is air cooled and designed with a dry crankcase for absolutely no risk of oil residue. The dry crankcase design assures no risk of oil residue carried to compression chamber. Low rotational speed for long service life, Better cooling system performance from multi stage compression, high efficiency cooling fan, compact streamline air passages on the cylinder and head, and cooling fins. Features: Dry Crankcase, 100% Oil Free: Dry compression chamber is always not enough!, FSCURTIS total oil free compressor uses dry crankcase design, absolutely no risk of oil residue carried to compression chamber. Cooling System: High efficiency cooling fan transmits great amount of heat, better performance results from multi stages of compression, compact streamlined air passages on the cylinder and head enhance cooling effect, 2-stage compression for 7.5HP and above models reduces power consumption and less heat accordingly, the copper tube between stages is fitted with cooling fans to reduce operating temperature effectively. Low Rotational Speed, Long Service Life: Industrial design of compressor ring reduces leakage and results in lower speed and longer life. 100 % Oil free 100 % Duty Cycle: Oil free compressed air for high quality demand Bearings: High precision grease-lubricated bearings. High temperature-resistant grease ensures long service life and constant operation. Compression Rings and Guide Rings: High precision machining along with self-lubricated material which resists wear and high temperature. Stainless, elastic structure enhances sealing effect and durability. Intake Valve: corrosion free leaf valve made of stainless steel coated with high temperature – resistant material effectively reduces noise and improves service life. 100% duty cycle is assured. Connecting Rod: Made of die-casting aluminium alloy is highly rust-resistant with great strength. CNC precise machining process ensures stable compressor operation. Piston: Casting with compact ingredient, precise machining followed by grinding. Surface coating with self-lubricated material. Ventilation of crankcase: Crankcase fitted with ventilation system on both sides enormously reduces operating temperature to increase bearing service life. #As per IS 5456: 1985: Code of practic for testing performance of positive of dislacement type air compressors. VW30 and VW50 are stage units, and others are two stage Option: Wheel mounted compressor on tank Base mounted compressor special application compressor”