[en] Putting together thermodynamics (phase behavior), heat transfer and mass transfer fundamentals; it was possible to structure a mathematical and numerical model to simulate the vaporization process of LPG in tanks. The simulation model allows studying any feeding process with gaseous LPG to an appliance, and therefore, to follow changes inside the LPG tank related with LPG composition and its properties, temperature and pressure. A continuous or by cycles supplying process of gaseous LPG from a tank to any appliance promotes a reduction of liquid LPG temperature, an increase on specific gravity of LPG in both phases, and also an increasing in the value calorific of gaseous LPG