An assessment of Flibe thermo-physical properties relevant to the prompt x-rays ablation of the liquid wall is presented with emphasis given to the equilibrium vapor composition and vapor pressure. The available data sets for Flibe thermo-physical properties, which cover a very narrow range of temperature have been extended and adjusted to cover the whole range of the liquid phase and to assure consistency with the estimated critical constants. Investigation of the equilibrium vapor composition showed a contradiction with previously published results regarding the stability of the mixed dimmer LiBeF3. New results for the vapor composition and total vapor pressure of Flibe also have been presented, compared to previous results, and used to calculate the temperature-dependent latent heat of vaporization.