Pump Erection
AS Power SolutionsPump Erection
pump and motor rotating components as a solid shaft from the motor thrust bearing, motor rotor and pump shaft down to the impeller. This entire rotating assembly pivots off the motor thrust bearing If the pump is not installed perfectly level and plumb, the impeller will attempt to center itself in the volute, while the motor and pump shaft rides against the motor sleeve bearing, upper bushing and line shaft bushings.
The pump bushings are not true bearings but rather rotor guides with a large (compared with the true hydrodynamic bearing in the motor) clearance between the rotor journal and the shaft. A true hydrodynamic bearing typically has 0.004-inch running clearance (one thousand per inch of shaft), while a guide bushing may have three to four times that amount with no ability to sustain a hydrodynamic loading.
Vertical circulating water pumps can be either pullout or non-pullout design. In a pullout design, the inner element of the pump can be removed for maintenance, leaving the suction bell, column, discharge elbow and discharge piping in place. A non-pullout design requires removal of the entire pump. This installation procedure addresses both configurations
Cementitious grout is old technology and does not provide the bonding (chemical and mechanical) required to achieve a monolithic design. Epoxy grouting is the grout material of choice for both new and existing repairs or upgrades. While epoxy grout may cost more than other materials, it is the media of choice because of the stress that the pump and system experience during startup and shutdown.
Proper installation begins with the sole plate, which is the foundation for the pump. A poorly installed foundation will result in premature failure. Prior to installation, the bottom of the sole plate should be grit-blasted to a white metal finish and painted with epoxy primer then installed flat and level within 0.002 inches overall using leveling bolts. Allow a minimum 3 to 6 inches of clearance between the concrete intake structure and the sole plate for epoxy grout.
