Abstract: A system that makes it possible to merge at least four fluids with a column for separating a feedstock, for example, in a simulated moving bed, comprises at least one trunnion-mounted ball valve, whereby this valve comprises at least one means that makes it possible to circulate one or more fluids, this fluid is placed inside the valve to ensure communication between two zones of the column or between at least one of said zones and at least one point that is outside of the column, and several openings (OA, OB) that are placed to ensure the circulation of fluids according to the stages that are necessary to the separation process that is carried out in said column.