Xylem AC8584C Series HSCS Base Mounted Centrifugal Pumps - Manual (Page 18)

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EVERY MONTH Check bearing temperature with a thermometer, not by hand. If bearings are running hot (over
Ê
180ºF), it may be the result of too much lubricant. If changing the lubricant does not correct the Ê
condition, disassembly and inspect the bearing. Lip seals bearing on the shaft may also cause the
Ê
housing to run hot. Lubricate lip seals to correct. Ê
EVERY 3 MONTHS Check the oil on oil lubricated units. Check grease lubricated bearings for saponification. This
Ê
condition is usually caused by the infiltration of water or other fluid passing the baring shaft Ê
seals and can be noticed immediately upon inspection, since it gives the grease a whitish color. Ê
Wash out the bearings with a clean industrial solvent and replace the grease with the proper type
Ê
as recommended. Ê
EVERY 6 MONTHS Check the packing and replace if necessary. Use the grade recommended. Be sure the lantern rings
Ê
are centered in the stuffing box at the entrance of the stuffing box piping connection. Ê
Take vibration readings on the bearing housings. Compare the readings with the last set of readings
Ê
to check for possible pump failure (e.g. bearings) Ê
Check shaft or shaft sleeve for scoring. Scoring accelerates packing wear. Ê
Check alignment of pump and motor. Shim up units if necessary. If misalignment reoccurs Ê
frequently, inspect the entire piping system. Unbolt piping at suction and discharge flanges to see if Ê
it springs away, thereby indicating strain on the casing. Inspect all piping supports for soundness
Ê
and effective support of load. Correct as necessary. Ê
EVERY YEAR Remove the upper half of the casing. Inspect the pump thoroughly for wear, and order replacement
Ê
parts if necessary. Ê
Check wear ring clearances. Replace when clearances become three (3) times their normal clear-
Ê
ance or when a significant decrease in discharge pressure for the same flow rate is observed. See Ê
Engineering Data Section for standard clearances. Ê
Remove any deposit or scaling. Clean out stuffing box piping.
Ê
Measure total dynamic suction and discharge head as a test of pump performance and pipe
Ê
condition. Record the figures and compare them with the figures of the last test. This is important, Ê
especially where the fluid being pumped tends to form a deposit on internal surfaces. Inspect foot
Ê
valves and check valves, especially the check valve which safeguards against water hammer when Ê
the pump stops. A faulty foot or check valve will reflect also in poor performance of the pump while Ê
In operation.
NOTE: The above time table is based on the assumption that after start-up, the unit had been constantly monitor
ed and

such a schedule was found to be consistent with operation, as shown by stable readings. Extreme or unusual applications or 
conditions should be taken into consideration when establishing the maintenance intervals.

MAINTENANCE TIME T ABLE