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MAINTENANCE
GENERAL MAINTENANCE AND PERIODIC INSPECTION
Operating conditions vary so widely that to recommend one schedule of preventative maintenance for all
centrifugal pumps is not possible. Yet, some sort of regular inspection must be planned and followed. We
suggest a permanent record be kept of the periodic inspections and maintenance performed on your pump.
This recognition of maintenance procedure will keep your pump in good working conditions, and prevent
costly breakdowns.
One of the best rules to follow in the proper maintenance of your centrifugal pump is to keep a record of
actual operating hours. Then, after a predetermined period of operation has elapsed, the pump should be
given a thorough inspection. The length of this operating period will vary with different applications, and
can only be determined from experience. New equipment, however, should be examined after a relatively
short period of operation. The next inspection period can be lengthened somewhat. This system can be
followed until a maximum period of operation is reached which should be considered the operating
schedule between inspections. See Maintenance Time Table below.
PERIOD
Check bearing temperature with a thermometer, not by hand. If bearings are running hot (over 180°),
Every
it may be the result of too much lubricant. If changing the lubricant does not correct the condition,
month
disassemble and inspect the bearings.
Check grease lubricated bearings for saponification. This condition is usually incurred by the infiltra-
tion of water or other fluid past the bearing shaft seals and can be noticed immediately upon inspec-
tion, since it gives the grease a whitish colour. Wash out the bearings with a clean industrial solvent
Every 3
and replace the grease with the proper type, as recommended.
months
Check the packing and replace if necessary. Use the grade recommended. Be sure the seal cages are
centred in the stuffing box at the entrance of the stuffing box piping connection.
Check shaft or shaft sleeve for scoring. Scoring accelerates packing wear.
Every 6
Check alignment of pump and motor. Shim up units if necessary. If misalignment recurs frequently,
months
inspect the entire piping system. Unbolt piping at suction and discharge flanges to see if it springs
away, thereby indicating strain on the casing. Inspect all piping supports for soundness and effective
support of load.
Remove the rotating element. Inspect thoroughly for wear, and order replacement parts if necessary.
Check wearing clearances between impeller inlet and suction cover or between impeller wear ring and
suction wear plate...
Remove any deposit or scaling. Clean out stuffing box piping.
Every
year
Measure total dynamic suction and discharge head as a test of pipe connection. Record the figures
and compare them with the figures of the last test. This is important especially where the fluid being
pumped tends to form a deposit on internal surfaces. Inspect foot valves and check valves, especially
the check valve which safeguards against water hammer when the pump stops. A faulty foot or check
valve will also reflect in poor performance of the pump while in operation.
NOTE: The above time table is based on the assumption that after start up, the unit had been
regularly monitored 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 and may require shorter maintenance intervals.
Maintenance Time Table
INSPECTION
8
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