A model of saturatedvapor pressure p = ps(T) is proposed, which takes into account both the features of the critical point (Tc, pc, ρc) and the behavior of the saturated vapor pressure psin the vicinity of the triple point (Ttr, ptr, ρtr).Based on the proposed model ps(T), all available information (479 experimental points) on the pressure of the refrigerants R1243zf, R1336mzz(E) and R1336mzz(Z) is generalized and the equations for the elasticity line are developed for the temperature range from Ttr to Tc.For these refrigerants, on the basis of the developed equations for saturated vapor pressure ps = ps(T), the values of the acentric factor and the normal Boyle temperature are calculated. A statistical evaluation of the elasticity line equations was performed: for R1243zf, R1336mzz(E,) and R1336mzz(Z) the following mean absolute deviation (AAD) values were obtained respectively: Yin J. et al (2020), AAD = 0.0182%;Sakoda N. et al (2021), AAD=0.034%;Li Sh.(2020), AAD = 0.0426%. The results obtained are discussed.