Page 127 - Know and Understand Centrifugal Pumps
P. 127
Know and Understand Centrifugal Pumps
New equipment is installed. Other changes occur with maintenance.
The equipment loses its efficiency. Install gauges on your pumps and
teach the operators and maintenance personnel to interpret the
information.
The dynamic system
Let’s continue with system curves. Up to this point, all elevations,
temperatures, pressures and resistances in the drawings and graphs of
systems and tanks have been static. This is not reality. Let’s now
consider the dynamic system curve and how it coordinates with the
pump curve.
Variable elevations
In the next graph we observe that at the beginning of the operation,
the lower tank is 111, and the work of the pump is to complete the
distance between the surface level in the lower tank and the discharge
elevation above at the upper tank. At the end of the operation, the
lower tank is empty and the work of the pump is to complete the new
distance between the two elevations. Consider the next graphic (Figure
8-9).
At the beginning of the operation, the work of the pump is to complete
elevation Hsl. This elevation becomes Hs2 at the end of the operation.
END
BEGINNING
Figure 8-9
110
