Steam enters a diffuser operating at steady-state with a pressure of 15 psia, a temperature of 300 ºF, and a velocity of 500 ft/s. Steam exits the diffuser as a saturated vapor, with negligible kinetic energy. Heat transfer occurs from the steam to its surroundings at a rate of 19.59 Btu/lbm of steam flowing. Neglecting potential energy effects, determine the exit pressure in psia.