Upon an increase in speed of the shaft being controlled, the sleeve of centrifugal governor 1 moves upward, shifting the spool of valve 2 upward. Hydraulic fluid, delivered to valve 2, is directed to the upper end of servomotor 3, moving piston 4 and valve member 5 downward and thereby reducing the supply of steam. This changes the amount of steam flowing into extraction chamber A and, consequently, the pressure in the chamber. The change in pressure actuates the membrane of pressure regulator 6, leading to the shifting of valve member 7.
$4230$CHP,Rg$