Gas-phasePVT properties of 1,1,1,2,3,3-Hexafluoropropane

We have measured the gas-phasePVT properties of 1,1,1,2,3,3,-hexafluoro-propane (R-236ea), which is considered to be a promising candidate for the replacement of 1,2-dichlorotetrafluoroethane (R-114). The measurements have been performed with a Burnett apparatus over a temperature range of 340 390 K and at pressures of 0.10–2.11 MPa. The experimental uncertainties of the measurements were estimated to be within ±0.5 kPa in pressure. ±8 mK in temperature, and ±0.15% in density. A truncated virial equation of state was developed to represent thePVT data and the second virial coefficients were also derived. The saturated vapor densities were also calculated by extrapolating the gas-phase isotherms to the vapor pressures. The critical density estimated from the rectilinear diameter was compared with the experimental value. The purity of the R-236ea sample used in the present measurements was 99.9 mol%. Paper presented at the Fourth Asian Thermophysical Properties Conference, September 5–8, 1995, Tokyo, Japan.