A portable dental delivery system is provided which is composed of a plurality of individual module sections. The portable delivery system provides all basic tools and accessories which are necessary for a dentist to perform all types of dental work which may be required by patients. The dental delivery system includes a quiet running, pressurized clean air supply system for operating the various tools and accessories utilized by the dentist. A hermetically enclosed refrigeration compressor unit is modified to provide an adequate supply of pressurized air in an extremely quiet manner. The temperature of the compressor unit is maintained at a safe level by an oil cooling system. A pump draws oil from the base of the compressor unit, passes it through a radiator which is additionally cooled by an axial fan. The oil is returned to the compressor unit at the top of the housing at a location which will cause the oil to impinge directly upon the cylinder head of the compressor. Oil entrained in the pressurized outlet air is collected in an oil coalescer. A check valve is provided downstream of the coalescer and ahead of an air storage tank. A normally closed solenoid is connected to the lowermost portion of the coalescer so that upon deenergization of the compressor unit the solenoid is automatically opened unloading the outlet pressure so as to drive any accumulated oil in the coalescer back into the oil return line for the housing.
