W type radiant tube W Type Radiant Tube Application: mostly used in continuous annealing, vertical annealing furnace of galvanizing lines. In the nitrogen and hydrogen protection atmosphere, by burning of natural gas or coke oven gas inside the tube, heat the strip steel from room temperature to 750-950℃ quickly and evenly through the outer tube radiation heat transfer for the annealing treatment. The straight tube sections are made by centrifugal casting. Centrifugla Casting Radiant Tube Material: ZG40Cr25Ni20Si2,ZG40Ni35Cr25Nb, ZG45Ni48Cr28W5Si2, ZG30Cr25Ni12, etc.