A tube arrangement comprising a first metal tube, a second metal tube, a first sleeve part, and a second sleeve part, wherein a first end region of the first metal tube comprises a first outer threading and a second end region of the second metal tube comprises a second outer threading, wherein the first sleeve part is made of metal and comprises a first inner threading and the second sleeve part is made of metal and comprises a second inner threading, wherein the first end region is configured to be joined with the second end region via a first butt weld joint, and wherein a first proximal sleeve end of the first sleeve part is configured to be joined with a second proximal sleeve end of the second sleeve part via a second butt weld joint, wherein the first sleeve part comprises a first outer surface extending at a first acute angle (α) to an axial centre axis of the first sleeve part and forming a first conical sleeve portion with its wide end at the first proximal sleeve end, and the second sleeve part comprises a second outer surface extending at a second acute angle (β) to an axial centre axis of the second sleeve part and forming a second conical sleeve portion with its wide end at the second proximal sleeve end, wherein each of the first and second metal tubes (1, 4) has a nominal diameter, Dnom, and a nominal cross sectional area, Anom, wherein the first sleeve part comprises a first distal sleeve end opposite to the first proximal sleeve end and the second sleeve part comprises a second distal sleeve end opposite to the second proximal sleeve end, wherein the first inner threading ends at a first threading end within a region of the first distal sleeve end, and the first sleeve part having a first threading end cross sectional area, A1, at the first threading end, wherein the second inner threading ends at a second threading end within a region of the second distal sleeve end, and the second sleeve part having a second threading end cross sectional area, A2, at the second threading end, characterised in that when the first and second proximal sleeve ends (32, 34) are joined by the second butt weld joint, at the second butt weld joint the first and second conical sleeve parts (8, 10) including the second butt well joint are configured to have a welding plane cross sectional area, Aweld, wherein a first length L1 extends between A1 and Aweld, and a second length L2 between A2 and Aweld, and wherein the first acute angle (α), and the second acute angle (β) are formed by: - Aweld being within a range of 1.3 - 2.3 times Anom, - each of A1 and A2 being within a range of 0.3 - 0.5 times Aweld, and - each of L1 and L2 being within a range of 0.8 - 1.5 times Dnom. a first sleeve part, and a second sleeve part, wherein a first end region of the first metal tube comprises a first outer threading and a second end region of the second metal tube comprises a second outer threading, wherein the first sleeve part is made of metal and comprises a first inner threading and the second sleeve part is made of metal and comprises a second inner threading, wherein the first end region is configured to be joined with the second end region via a first butt weld joint, and wherein a first proximal sleeve end of the first sleeve part is configured to be joined with a second proximal sleeve end of the second sleeve part via a second butt weld joint, wherein the first sleeve part comprises a first outer surface extending at a first acute angle (α) to an axial centre axis of the first sleeve part and forming a first conical sleeve portion with its wide end at the first proximal sleeve end, and the second sleeve part comprises a second outer surface extending at a second acute angle (β) to an axial centre axis of the second sleeve part and forming a second conical sleeve portion with its wide end at the second proximal sleeve end, wherein each of the first and second metal tubes (1, 4) has a nominal diameter, Dnom, and a nominal cross sectional area, Anom, wherein the first sleeve part comprises a first distal sleeve end opposite to the first proximal sleeve end and the second sleeve part comprises a second distal sleeve end opposite to the second proximal sleeve end, wherein the first inner threading ends at a first threading end within a region of the first distal sleeve end, and the first sleeve part having a first threading end cross sectional area, A1, at the first threading end, wherein the second inner threading ends at a second threading end within a region of the second distal sleeve end, and the second sleeve part having a second threading end cross sectional area, A2, at the second threading end, characterised in that when the first and second proximal sleeve ends (32, 34) are joined by the second butt weld joint, at the second butt weld joint the first and second conical sleeve parts (8, 10) including the second butt well joint are configured to have a welding plane cross sectional area, Aweld, wherein a first length L1 extends between A1 and Aweld, and a second length L2 between A2 and Aweld, and wherein the first acute angle (α), and the second acute angle (β) are formed by: - Aweld being within a range of 1.3 - 2.3 times Anom, - each of A1 and A2 being within a range of 0.3 - 0.5 times Aweld, and - each of L1 and L2 being within a range of 0.8 - 1.5 times Dnom. - Aweld being within a range of 1.3 - 2.3 times Anom, - each of A1 and A2 being within a range of 0.3 - 0.5 times Aweld, and - each of L1 and L2 being within a range of 0.8 - 1.5 times Dnom.