The Rankine cycle is the fundamental operating thermodynamic cycle for steam turbine power generation plants. Subcooled liquid water is pressurized by a feed pump (1→2), vaporized and superheated at constant pressure inside the boiler across the liquid-vapor saturation dome (2→3), expanded isentropically through a steam turbine to drive an electrical generator (3→4), and fully condensed back into liquid inside a surface condenser (4→1).