Abstract: A method and apparatus for supplying superheated steam at desired temperatures and pressures to a steam turbine. First source steam from a boiler steam drum passes through a control valve to form regulated steam which is conducted through a heat exchanger where a portion of it is condensed. The partially condensed regulated steam exhausted from the heat exchanger is throttled by a throttling valve to a lower pressure to form control steam and the vapor therein is separated from the liquid. The vapor is transmitted through the heat exchanger and absorbs heat from the regulated steam also passing therethrough. Cooperative adjustment of the control valve and throttling valve permits gradual adjustment of the control steam's temperature and pressure leaving the heat exchanger. When the control valve is completely open, the temperature of the control steam leaving the heat exchanger is a maximum which cannot be increased by further manipulation of the control and throttle valves.