Abstract: Crimping device (1) for reducing the diameter of collapsible valves, said device (1) including at least two independent cylindrical crimping units (2, 3, 4) that are each adapted to crimp a different specific part of a valve, independently from the other crimping unit(s), each of said unit (2, 3, 4) comprising a diaphragm rotation crimping mechanism that includes crimping jaws, and wherein each unit (2, 3, 4) comprises an actuator for activating said mechanism, characterized by the fact that said actuator is a handling screw (51, 61, 71) that is tangentially fixed to the external surface of the cylindrical crimping unit (2, 3, 4).