Savemax – Oil/Gas Fired Boilers are the basic 3 pass internal furnace smoke tube type design in which flue gases are inside the tubes while water is outside the tubes in the shell. The combustion of oil and gas in a furnace requires atomization of the fuel. Since the fuel entering the burner in bulk amount is either in liquid or gas form, therefore it needs to be separated in fine droplets so that every last particle of the fuel could get burnt without leaving any traces.