turbine power when steam pressure is at the predetermined value the step of closing additional selected ones of the control valves is continued until no additional improvement in heat rate is obtained by the present invention there is disclosed a method for limiting pressure drop on control stage blading of a partial arc steam turbine in which steam supply is controlled in order to match turbine power to power demand the turbine uncludes a plurality of control valves each arranged for admitting steam to a selected arc of admission into the control stage blading the method comprises the steps of sequentially closing predetermined ones of the control valves to reduce turbine power output by reducing the arc of admission to a first predetermined value sliding steam pressure to a first reduced value to further reduce turbine power output while maintaining a constant arc of admission sequentially closing additional ones of the control valves to further reduce the arc of admission to a second predetermined value and to reduce turbine output power toward demanded power while holding steam pressure at the first reduced value and further sliding steam pressure to match turbine power to demanded power while holding the arc of admission at the second predetermined value while the principles of the invention have now been made clear in an illustrative embodiment it will become apparent to those skilled in the art that many modifications of the structures arrangements and components presented in the above illustrations may be made in the practice of the invention in order to develop alternate embodiments suitable to specific operating requirements without departing from the scope and principles of the invention as set forth in the claims which follow table i______________________________________600 psia pressureheat rate comparison btu kwh 62 5 50 37 5.