VAPOR-PRESSURE AND GAS-PHASE PVT DATA AND CORRELATION FOR 1,1,1-TRIFLUOROETHANE (R143A)

A constant volume apparatus has been used to measure the vapor pressur e and single phase densities (PVT) for 1,1,1-trifluoroethane (R143a), an ozone friendly refrigerant. The sample has a purity greater than 99 .91% by mass. The measurements were done from 244 to 365 K at pressure s up to 4.4 MPa and at densities ranging from 5% to 99% of the critica l density. The uncertainties involved in the measurement of temperatur e, pressure, mass, volume, and specific volume are explicitly given. T hirty-three values for the vapor pressure and sixty-three densities al ong six isochores are presented and have been compared with previously published data and correlations. A Wagner type correlation for the va por pressure and a Martin-Hou equation of state have been used to fit the measured data, which have been analyzed using the average absolute deviation, bias, and standard deviation. The gas phase densities have been used to determine the second virial coefficients.