Abstract: A purification system and a method for purification of slop oil and industrial emulsions, wherein the purification system can handle two processes in parallel, a slop oil purification process and an industrial emulsion purification process, said system comprising: —at least one slop oil centrifugal separator (5) into which slop oil is provided for separation of water and oil; —at least one emulsion centrifugal separator (25) into which an industrial emulsion is provided for separation of oil and water; —a first redirecting fluid connection (37, 37?) arranged for transferring oil separated from the industrial emulsion in the emulsion centrifugal separator (25) to the slop oil centrifugal separator (5) possibly via a slop oil tank (3).

Abstract: Tank for holding contents which can separate into different phases, said tank comprising at least two outlet pipes each provided through a bottom of the tank with a first end of the outlet pipes provided outside the tank and a second end provided inside the tank, the second ends of the at least two outlet pipes being provided at different heights within the tank.

Abstract: A method and a system for purification of oil, wherein the method comprises the steps of:—adding to a contaminated oil provided in a preparation tank a chemical booster for boosting capturing of impurities and/or a separation of phases in the contaminated oil;—waiting for allowing different phases to be separated;—pumping content out from the preparation tank through a fluid connection; sensing at least one property of the content in the fluid connection;—controlling a valve provided in the fluid connection to transfer the content to a next step in the purification process or to another destination in dependence of the sensed at least one property.