| abstract |
A mandrel (50) for forming helically coiled heat exchange tubes (80), the mandrel comprising: a roller (56) to form the tube into a helical coil (30); a drive (52) for rotating the roller; a carriage (82) for indexing the tube with respect to the roller, wherein the roller comprises a plurality of winding beams (60), which beams are arranged to be radially movable by associated powered adjustable supports (62) so as to permit rapid setting of the radius of a heat exchange coil formed on the roller. |