Isobaric vapor-liquid equilibrium (VLE) for two binary systems of 1,1,1-Trifluoro-2-(2,2,2-trifluoroethoxy) ethane+2-methyl-2-propanol and pentane+1,1,2,2-tetrafluoro-1-(2,2,2-trifluoroethoxy)ethane system have been measured at 101.3 kPa. The measurements were made in an equilibrium still, developed in a previous study, with circulation of both the vapor and liquid phases. The binary isobaric systems exhibit minimum boiling azeotropes. The thermodynamic consistencies of the experimental data were good by the Van Ness et al. and Herington methods. The experimental data for the binary systems investigated were correlated with activity coefficient equations. The nonrandom two-liquid (NRTL) equation yielded a good correlation of activity coefficients.