RP-1253 -- Measurement of Solubility, Viscosity and Density of R-125/143a (50/50) (R-507A) Refrigerant/Lubricant Mixtures PDF

The refrigerant vapor/liquid lubricant equilibrium viscosity reduction of two polyolesters (POE), viscosity grades 32 and 68 ISO VG, and one polyalkylene glycol (PAG), viscosity grade 68 ISO VG, were measured with R-507A from -5°C (23°F) to 125 degrees C (257°F) up to 500 psia. All three lubricants have a miscibility curve produced starting at 2%, and in increments up to 60% lubricant and refrigerant concentration determined from -40°C (-40°F) to 60°C (140°F). Using validated analytical methods, the viscosity, density and composition of the solubilized gas mixture in solution with the lubricant is obtained with constant gas vapor composition in the viscometer headspace. This refrigerant has a very small temperature glide, but it is still considered a blend.

The fractionation data presented was obtained from individual isothermal measurements. The isotherm for each temperature details the composition of the equilibrium of gas fractionation of R-125 and R143a in the lubricant, mixed vapor pressure, concentration of the total mixed blend (percent by weight) in the lubricant and viscosity in centipoises (cP) and centistokes (cSt). The raw data is presented as smoothed graphs and in tables based on a fixed vapor concentration.

Units: Dual