Valve body 1 is connected by ports to the water space in the boiler and to the feedwater pump. Feedwater from the pump is delivered through valve member 2 into the boiler and through the clearance between plunger a and body 1 into space d. From here it is discharged through pipeline 3, needle valve 4 and pipeline 9 to the suction line of the pump. From above, valve member 2 is subject to the pressure of the water in the boiler and is therefore held tightly to its seat. When the level drops in the boiler, float 5, located in chamber 6, moves downward, turning about fixed axis O. Chamber 6 is connected to both the steam and water spaces of the boiler. Needle valve member 4, linked by tie-rod 7 to float lever 8, moves upward and stops water discharge from space d to the suction line of the pump. The pressure in space d increases and valve member 2 is raised. At this, feedwater is delivered by the pump into the boiler until the level reaches the preset value. After this, float 5, counterbalanced by weight 10, rises, needle valve member 4 moves downward, connecting space d with the suction line. Valve member 2 returns to its seat.
$4274$CHP,Rg$