Function
Feedwater control valves regulate the feedwater flow to the steam generator. Since various configurations exist, the operating concepts also vary:
Full-load control valves are positioned within the main feedwater line. They are designed to handle the total water volume of the steam generator and to maintain a minimal pressure drop during full-load operation. In drum boilers, these valves control the drum water level and/or manage differential pressure regulation when speed-controlled feedwater pumps are used. In once-through boilers, flow control is primarily required in the lower flow range when the feedwater pumps cannot be throttled any further. Conversely, start-up, shutdown, and low-load operations demand the reliable management of high differential pressures at low feedwater flow rates.
