Method of welding a sleeve to a tube, and device obtained thereby

A method of welding a sleeve (10) to a tube (20), where the tube (20) has at least one outer layer (21) in a first material and at least one lumen (22) in fluid communication with the outside of the tube (20) through at least one lateral opening (23), and where the sleeve (10) has two end portions (11) opposite and open at respective ends (12) and is made of a second material not suitable for fusion with the first material of the outer layer (21) of the tube (20);

• the method comprising:
• covering at least a tract, including the lateral opening (23), of the outer layer (21) of the tube (20) with an outer coating (24) of a third material compatible with fusion with the second material of the sleeve (10);
• putting the sleeve (10) onto said coated tract of the tube (20) at the lateral opening (23);
• putting onto end portions (11) of the sleeve (10) respective protective elements (40), of a material that cannot be fused with the materials of the sleeve (10) and of the outer coating (24) of the tube (20);
• applying on at least one part of each end portion (11) of the sleeve (10) covered by a protective element (40) a respective heat-shrink element (30);
• supplying each heat-shrink element (30) with a quantity of heat (Q) which by heating it causes it to shrink and compress the respective end portion (11) of the sleeve (10) against the tube (20), where this quantity of heat (Q) is transmitted to the end portion (11) of the sleeve (10) bringing it to a temperature equal to or higher than a melting temperature of the second material and the third material, thereby obtaining a welding of the sleeve (10) to the tube (20) and producing a device (1) comprising the tube (20) with the sleeve (10).