METHOD AND SYSTEM FOR PURIFICATION OF OIL

A method and a system for purification of contaminated oil. The method comprising providing contaminated oil into a disc stack centrifugal separator (3). The disc stack centrifugal separator comprises a light phase outlet chamber (33) and/or a heavy phase outlet chamber (31) in which a fluid level can be controlled. Separating the contaminated oil in the disc stack centrifugal separator (3) into a light phase and a heavy phase. Measuring one or more properties in a light phase retrieved from the disc stack centrifugal separator (3), wherein said one or more properties comprise one or more of a density, a viscosity, an amount of heavy phase content and a flow rate of the light phase. Controlling a backpressure provided to a heavy phase outlet (5b) and/or a light phase outlet (5a) of the disc stack centrifugal separator (3) and hereby controlling a fluid level in the heavy phase outlet chamber (31) and/or light phase outlet chamber (33), said controlling being dependent on at least one value of said one or more measured properties.