The current regulations regarding respect for the environment in which we live, enforce companies in the petrochemical industry to treat their hazardous industrial waste, which can be transformed into secondary raw materials. The main waste created by the petrochemical industry is slop oil, which is no other than a material made up from heavy hydrocarbons and other impurities, generated by the residues of a petroleum product mixed with water and which typically forms in the sediment deposits. In this case, the centrifuge, which must be suitable for use in explosion-risk areas and ATEX certified, becomes an indispensable aid for cleaning these tanks and for solid/liquid separation and successive oil/water separation of the slop oil. For applications with particular products it is also possible to set-up the centrifuge with membrane with nitrogen.