Tube for heat exchanger

An elongate tube for a heat exchanger, the tube comprising:

• a first end and a second end for connection to, respectively, a first header and a second header of the heat exchanger;
• an outer wall encompassing an internal volume, the internal volume providing at least two channels for carrying a heat exchange fluid a length of the tube between the first header and the second header;
• and
• at least one seam in the outer wall extending the length of the tube, the at least one seam including a pair of opposed flanges, the flanges extending into the internal volume to divide the internal volume into the at least two channel, the outer wall joined together along the at least one seam, wherein the tube has proximate the first end a first end region and proximate the second end a second end region, and between the first end region and the second end region an intermediate region, the tube being flattened along substantially all of the length such that the flanges divide the internal volume into at least two flattened lobes, each of the at least two lobes including one of the at least two channels and each of the at least two lobes extending laterally away from the flanges relative to the length of the tube, and the at least two lobes flatter in the intermediate region than the the at least two lobes in at least one of the first end region and the second end region.