Centrifugal Pumps Design and Application 2nd ed - Val S. Lobanoff, Robert R. Ross (Butterworth-Heinemann, 1992)

164 Centrifugal Pumps: Design and Application
Figure 10-32. Performance of two half-capacity full head pumps installed in parallel
plotted against system head curve.
shared equally, and there is less chance of a pump operating at less than
minimum continuous stable flow. Figure 10-32 shows our system curve
and two half-capacity full head pumps installed in parallel. In this particular
system, parallel configuration is a poor choice. When only one
pump is running, it is necessary to throttle to stay within operating range.
Parallel configuration should be considered in systems where a substantial
portion of the head is static. When pump configuration is not
clear cut, it is wise to plot each station curve along with pump curves and
carefully analyze parallel versus series operation.
Waterflood Pumps
Many types of pumps are used to extend the life of declining oil fields
by injecting displacing fluids at pressures ranging from 2,OCX) psi to
8,000 psi. In waterflooding applications (secondary recovery), centrifugals
are preferred when injection capacities exceed 10,000 BPD. Typical