CRISTIAN PATRASCIOIU, MARIANA VALENTINA PETRE TUBULAR FURNACES PERFORMANCES STUDY USING UNISIM FPH SIMULATOR The paper is presenting and analyzing the Unisim FPH simulator used for simulate the tubular furnaces. The paper is structured in for parts. First part is dedicated to describe and comment the principal commands utilized on the simulators configuration. The geometric and operating data utilized were from a Catalytic Reforming unit. The next two parts present the simulation results and importing of the heated stream’s properties (gasoline). The last part presents the comparison between the results obtained with Unisim FPH simulator and the result obtained during classic calculation with formulas from literature. The results have revealed both common and different features of the two mathematical models.