Acting on membrane 1 of the regulating valve is the difference in the pressures in the steam superheater and in pipeline 10 connected to the boiler drum. Membrane 1 is linked to lever 2 which turns about fixed axis A. Attached to the end of lever 2 is a chain which runs over pulley 3, turning about an axle mounted on lever 4. Lever 4 has weight 11 at one end and the other end is linked to valve 5. When the steam consumption is increased, membrane 1 is bent upward, compressing spring 6. This turns lever 2 clockwise, lever 4 is moved downward by weight 11 and plunger 5 moves upward, increasing the water supply to the boiler. The second impulse actuating the regulator is obtained by the change in the water level in the boiler drum which is connected to thermostatic tube 7 with an elongating rod. The right end of the rod is fixed and the other end is linked to bell-crank lever 8 to which tie-rod 9 is hinged. Tie-rod 9 is linked to the chain whose other end is secured to lever 2 of the valve. The lower end of tube 7 is connected to the boiler drum under the water level; the upper end, to the drum above the water level, occupied by steam. When the water level in the boiler drum drops, the rod of thermostatic tube 7 is elongated, lever 8 is turned counterclockwise so that tie-rod 9 moves downward. This lowers lever 4 and raises plunger 5, increasing the water supply to the drum. If steam consumption is reduced, the elements of the regulator operate in the reverse direction.
$3907$LHP,Rg$