Page 144 - Centrifugal Pumps 2E

126 Centrifugal Pumps: Design and Application

Figure 9-11. Water supply pump of pull-out design with below ground dis-
charge,

shows a below ground discharge application with pull-out construction.
This construction is particularly well suited for locations where the dis-
charge is located below the water level because the nozzle can be perma-
nently welded to the discharge piping system. Solid shaft electric motors
are most commonly used as drivers.

Condenser Cooling Water Pumps

Installation considerations, configuration, and driver requirements for
these pumps are in general the same as for water supply pumps. How-
ever, in addition, the following must be considered:
* When selecting lubrication method for the column bearings, neither oil
nor grease can be used, because small amounts of hydrocarbon enter-
ing the condenser will impair the heat-transfer properties.