electromagnetic pump for electrically - conductor fluid containing an external pipe enveloped by magnetic half - yokes containing slots in which half - coils are installed forming two polyphase half - windings permitting a symmetry plane . the fluid is contained in a duct comprised between the external pipe and an internal pipe which is closed and contains a magnetic core . the duct is provided with partitions which separate the duct into two active half - ducts in which the fluid flows and two passive streams in the vicinity of the joint plane in which the fluid scarcely flows at all . pump with a high degree of efficiency and easy to dismantle .