Theoretical and experimental investigations of various methods for protection against fires of vessels containing liquefied petroleum gases (LPG) (safety relief valves, intumescent fire retardant coatings, thermal isolation) have been carried out. A simple mathematical model has been proposed, which describes dependences of various parameters on time. These parameters are temperature, pressure and mass of LPG, temperatures of the vessel's walls and thermal protection layer. The case of total fire engulfment of the vessel with LPG was considered. Experiments have been executed, which were aimed on the investigation of the behaviour of vessels with LPG (50 l), equipped with protective devices during total fire engulfment. It was found out that the safety valve prevented an explosion of the vessels without any other protective measures. The presence of the intumescent fire retardant coating caused a significant delay in operation of the safety valve. A rather good agreement between the theoretical and experimental data was obtained. It has been revealed that the considered methods for protection of LPG vessels are promising in regard to prevention of explosions in these vessels at the fire engulfment.