.ThermoSysPro.Properties.Common.ThermoFluidSpecial.ThermoProperties_pT .ThermoSysPro.Properties.Common.ThermoFluidSpecial.ThermoProperties_pTA base class for medium property models which use pressure and temperature as dynamic states. This is a reasonable model for fluids that can also be in the gas and liquid regions, but never in the two-phase region.