In the transformer production, high vacuum and oil lubricated vacuum pumps are historically very common. Recently the market is changing, paying attention at life cycle costs and looking for energy efficient solutions. For this reason Gieffe Systems engineers replaced a complete system, consisting of an oil lubricated vacuum pump and PD blowers, with a double stage vacuum system, equipped with a dry screw vacuum pump and PD blower in series. It was a great success in this Italian company, which is benefiting outstanding energy performance in the drying transformer process (0,001 mbar(a) ultimate absolute pressure - 970 m³/h max. capacity).