Working of Super heater: Superheater header mounted against the tube sheet in the smoke box.The steam is then passed through a number of superheater elements—long pipes which are placed inside special, widened fire tubes, called flues. Hot combustion gases from the locomotive's fire pass through these flues just like they do the fire tubes, and as well as heating the water they also heat the steam inside the super heater elements they flow over. The super heater element doubles back on itself so that the heated steam can return; most do this twice at the fire end and once at the smoke box end, so that the steam travels a distance of four times the header's length while being heated. The superheated steam, at the end of its journey through the elements, passes into a separate compartment of the super heater header and then to the cylinders as normal.