You are here:
FAT curves
FAT curves
jistre, the proposed pump curves prior to rebuild showed head rising to shut off, but the FAT curves did not demonstrate the same phenomenon. The pumps have been purchased, therefore, starting over with new pumps is not possible. The pump rebuild was to provide higher flow and head at the BEP.
The issue with running the minimum flow lines continuously is that the metallurgy was not designed for continuous flow and failures have occurred in the past.
If money was not an issue ( !), a min flow recirc control valve designed specifically for this case ( valve , piping + metallurgy) would allow continuous operation at the min flow case . However, the measurement of min flow must be assured as accurate- for the flow element on the main line , a small non condensable vapor bubble in the DP sensing lines can indicate adequate flow when in fact zero flow is occurring.
So, a back-up high pump outlet pressure pressure switch would also be used to protect the pump, perhaps with a time delay equal to the stroke period of the min flow recirc control valve. Chemical pumps
So, a back-up high pump outlet pressure pressure switch would also be used to protect the pump, perhaps with a time delay equal to the stroke period of the min flow recirc control valve. Chemical pumps
2011-06-28
