Now the valve is opened, and steam is allowed to enter the tank. Heat transfer takes place with the surroundings such that the temperature in the tank remains constant at 300F at all times. The valve is closed when it is observed that one-half of the volume of the tank is occupied by liquid water. The properties of water are v1 = 6.4663 ft3/lbm, u1 = 1099.8 Btu/lbm, vf = 0.01745 ft3/lbm, vg = 6.4663 ft3/lbm, uf = 269.51 Btu/lbm, ug = 1099.8 Btu/lbm, and hi = 1210.9 Btu/lbm