The gas analysis and inlet conditions of 1440 psi at 60°F in an inlet separator are known. The pressure safety valve pops at 1440 psi to the flare header. Calculate the temperature of the gas downstream of the PSV (constant enthalpy flash).

A. Temperature-Pressure Flash

Step 1: Set the "Initial Conditions":

• Select "Temperature-Pressure Flash", and set "Temperature" to 60°F and "Pressure" to 1453 psia. (Note: 13 psi absolute pressure chosen for 3000 feet elevation).

Step 2: Enter "Input Stream":

• Add "Components" and enter "mole %" as in Example 1.

Step 3: "Execute Flash".

Step 4: From the calculated "Data", read the "Enthalpy" of -1.96374E+4 cal/mol.

B. Pressure-Enthalpy Flash

Step 5: Reset the "Initial Conditions":

• Select "Pressure-Enthalpy Flash", and set "Pressure" to 13 psia and "Enthalpy" to -1.96370E+4 cal/mol.

Step 6: From the calculated "Data", read the "2-Phase Flash Results at Temperature" of -63.9°F (constant enthalpy flash). This will be the outlet temperature of the relief valve.