When the steam pressure drops in the boiler, bellows 1 expands, turning lever 2 about fixed axis O. This deflects jet valve nozzle 3 to the left. Hydraulic fluid from the jet valve is directed through left channel a to the left end of servomotor 5, moving piston 6 to the right and thereby increasing the fuel and air supply to the boiler. As piston 6 moves to the right, lever 7 raises cam 8, compressing spring 4, which returns jet valve nozzle 3 to the central position. The regulator is switched off with valve 9 which, in the open position, connects the two ends of servomotor cylinder 5, equalizing the pressure in them regardless of the position of jet valve nozzle 3. Flow-control valve 10 regulates the rate of fluid flow to the servomotor. Upon an increase in pressure in the boiler, the elements of the regulator operate in the reverse direction.
$4271$CHP,Rg$