Upon a drop in speed of the shaft being controlled, the sleeve of centrifugal governor 1 moves downward, turning lever 2 which shifts the spool of valve 3. At this, fluid from the valve is delivered to the lower end of servomotor 4. Piston 5 moves upward, turning lever 6 and opening valve member 7 which has a weaker spring than valve member 8. After the stem of valve member 7 reaches stop a, valve member 8 begins to open. The opened valve members admit steam at two pressures (live and exhaust steam), thereby increasing the speed of the turbine. Upon an increase in the shaft speed, the elements of the regulator operate in the reverse direction, valve member 8 closing first and then valve member 7. If the pressure drops in the accumulator or if there is an interruption in the supply of exhaust steam, piston 9 of the pressure regulator moves upward, shifting valve spool 10 upward. Fluid from the valve is delivered to the upper end of servomotor 11, moving piston 12 downward. This closes valve member 7 and opens valve member 8, changing over to turbine operation with only live steam.
$4227$CHP,Rg$