Specifications include, but are not limited to: The compressor shall be an air-cooled, oil lubricated, four stage, three cylinder, reciprocating compressor. The crankcase shall be cast of a high strength, aluminum alloy. The crankshaft shall be of a single piece forged steel construction, and supported in the crankcase by three long-life roller bearings. The connecting rods shall be of single piece design and constructed of a high strength aluminum alloy. Each connecting rod shall incorporate a roller bearing at the crank end and needle bearing at the pin end. The pistons shall be constructed of an aluminum alloy. Piston rings on the second and third stage are of cast iron; first and fourth stage rings shall be of a high strength polymide. The final stage shall incorporate a ringed, free-floating, aluminum piston, which is driven by a guide piston and the previous stage’s discharge pressure. The cylinders shall be of cast iron construction with deep cooling fins on the external surface for optimum heat dissipation. The cylinders shall be arranged in a “W” configuration with the first and second stage sharing one common stepped cylinder. Each cylinder shall be located directly in the cooling fan’s blast. The cylinders shall be removable from the crankcase. The compressor’s flywheel shall be of cast iron construction. A multi-wing, high velocity cooling fan shall be integral to the flywheel.
