Abstract: A superheater supported in a furnace and composed of a plurality of piping lengths in which the individual pipe lengths are supported in the furnace by a pair of hanger rods pivotally mounted to the pipe lengths substantially at the ends of the pipe lengths, the rods being slidably mounted to a support surface exterior of the furnace whereby the rods are free to move in a longitudinal direction parallel to the longitudinal axis of the pipe lengths. The inlet and outlet headers to and from the superheater can comprise the support surface for the hanger rods.