1. The problem statement, all variables and given/known data Refrigerant 134-a enters the expansion valve of a refrigeration system at 160 psia as a saturated liquid and leaves at 30 psia. Determine the temperature and internal energy changes across the valve. 2. Relevant equations Δu=cv*ΔT 3. The attempt at a solution I'm not sure how to get the temperature change. Since we know it is initially a saturated liquid, I was able to get the initial temperature from a property table to be 109.5 °F Is there a way to tell if the refrigerant is a saturated mixture or a superheated vapor after the pressure change? Can we assume its a saturated mixture?