Abstract: In a magnetic polarization device for a fuel supply circuit, comprising multi-pole bar magnets contained in a casing which has internal passage vanes for the fuel, each bar magnet is made up of a different number of contiguous bipolar magnetic segments with magnetic fields of increasing intensity from one end to the other, which are aligned axially with one another with like-directed magnetic polarities adjacent each other, and which have unlike-directed magnetic polarities corresponding to the ends of each bar, and one or more fluid-carrying bars made of a ferromagnetic material are arranged parallel to each multi-pole bar magnet.