Abstract: A device for spreading two flanges (1, 2) mounted in opposite position in a pipe system (3), which device mainly comprises a conical screw element (7) to be inserted into a continuous hole of a flange, said element having an axial opening, in which fits a pressure member (6) having a pressure head face for the axial displacement of the pressure member in said opening, wherein the screw element (7) has a screwthread with at least three leads in order to adapt said device for a greater variety of hole diameters in the flanges (1, 2) and to guarantee the necessary guiding of the conical screw element (7) during insertion thereof.