Coupling arrangement comprising a first pipe section and a first radial flange that is located on the first pipe section, the first flange comprising external threads, a second pipe section and a second radial flange that is located on the second pipe section and facing the first flange, the second flange comprising an engagement surface, and a connection element that has - internal threads that engages the external threads of the first flange, and - an internal flange that engages the engagement surface of the second flange, the connection element thereby pressing the second flange towards the first flange when the connection element is screwed onto the first flange, a first transition section that is located where the first pipe section transitions into the first flange, the first transition section having a gradually increasing thickness in a direction from the first pipe section towards the first flange, and a second transition section that is located where the second pipe section transitions into the second flange, the second transition section having a gradually increasing thickness in a direction from the second pipe section towards the second flange, wherein the first flange comprises an abutment surface that abuts an abutment surface of the second flange, and a gasket is arranged in a groove between the first flange and the second flange, a predetermined pre-compression of the gasket being obtained by the abutment between the abutment surfaces (19, 212) of the flanges (16, 26), when the first flange and the second flange are connected to each other, characterized by a groove located adjacent the abutment surface of the first radial flange, on an inner side of the abutment surface as seen in a radial direction, a protruding rim being located next to the groove, on an inner side of the groove as seen in the radial direction, the second radial flange having a corresponding groove that is located adjacent the abutment surface of the second radial flange, on an inner side of the abutment surface as seen in the radial direction, and a protruding rim located next to the groove, on an inner side of the groove as seen in the radial direction, wherein the groove in the first radial flange and the corresponding groove in the second radial flange together form the groove for the gasket, the first flange comprises a protrusion that extends towards and at least partially over a periphery of the second flange, said periphery of the second flange being a periphery of the second flange that is most distant from the center axis that extends through the pipe sections (12, 22) and the flanges (16, 26), so that the second flange comprises no other part or section that is more distant from the axis than said periphery, as seen in the radial direction, and the protrusion comprises a surface that extends in the radial direction of the first flange, in parallel to said radial direction, said surface facing the connection element and being a free end which has no contact with any other part of the coupling arrangement when the abutment surface of the first flange abuts the abutment surface of the second flange. - internal threads that engages the external threads of the first flange, and - an internal flange that engages the engagement surface of the second flange, the connection element thereby pressing the second flange towards the first flange when the connection element is screwed onto the first flange,