During the annual maintenance shutdown of ELPE Refinery in the Aspropirgos Industrial Area, a major overhaul was carried out on all integrally geared compressors type RG, supplied by MAN. Many units were found with damaged compressor impellers. Our Reverse engineering department took over to manufacture new compressors, as delivery time from makers, was too long. In cooperation with our in-house metallurgical laboratory, engineering designers and CNC engineers, we managed to scan samples, produce 3-D models and relative engineering drawings, identify materials and finally produce all 4 stages of compressor wheels, for 2 units.