The structure design of densely arranged tubes and membrane wall with finned tubes ensures that it would never go overheating outside the furnace tube wall, and the sealing would be maintained. The temperature of insulation and sealing steel plates would not go over 250℃, which ensures the sealing steel plates’ ability of oxidation corrosion resistance. he design of internal seal casing and external embossed casing not only ensures good sealing, but also gives the boiler a better appearance http://www.chinaboilermaker.com