Goulds Pumps 3498 - IOM - Manual (Page 39)

Check alignment of pump and driver. Shim up units if
necessary. If misalignment reoccurs frequently, 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. Correct as necessary.
EVERY YEAR
Remove the upper half of the casing. Inspect the pump
thoroughly for wear, and order replacement parts if
necessary.
Check wear ring clearances. Replace when clearances
become three (3) times their normal clearance or when a
significant decrease in discharge pressure for the same flow
rate is observed.
Remove any deposit or scaling. Clean out stuffing box
piping.
Measure total dynamic suction and discharge head as a test of
pump performance and pipe condition. 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
reflect also in poor performance of the pump while in operation.
NOTE: The above timetable is based on the assumption that
after startup, the unit has been constantly 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 when
establishing the maintenance intervals.
MAINTENANCE OF FLOOD DAMAGED PUMPS
The servicing of centrifugal pumps after a flooded
condition is a comparatively simple matter under normal
conditions.
Bearings are a primary concern on pumping units. First,
dismantle the bearings; clean and inspect them for any
rusted or badly worn surfaces. If bearings are free from rust
and wear, reassemble and relubricate them with one of the
recommended pump lubricants. Depending on the length of
time the pump has remained in the flooded area, it is
unlikely that bearing replacement is necessary; however, in
the event that rust or worn surfaces appear, it may be
necessary to replace the bearings.
Next, inspect the stuffing box, and clean out any foreign
matter that might clog the box. Packing that appears to be
worn, or no longer regulates leakage properly should be
replaced. Mechanical seals should be cleaned and
thoroughly flushed.
Couplings should be dismantled and thoroughly cleaned.
Lubricate the coupling with one of the coupling
manufacturer’s recommended lubricants where required.
Any pump that is properly sealed at all joints and
connected to both the suction and discharge should exclude
outside liquid. Therefore, it should not be necessary to go
beyond the bearings, stuffing box, and coupling when
servicing the pump.
LUBRICATION
GREASE
Grease lubricated ball bearings are packed with grease at
the factory and ordinarily will require no attention before
starting provided the pump has been stored in a clean, dry
place prior to its first operation. The bearings should be
watched the first hour or so after the pump has been started
to see that they are operating properly.
The importance of proper lubrication cannot be over
emphasized. It is difficult to say how often a bearing should
be greased, since that depends on the conditions of
operation. It is well to add one ounce of grease at regular
intervals, but it is equally important to avoid adding too
much grease. For average operating conditions, it is
recommended that 1 oz. of grease be added at intervals of
three to six months, and only clean grease be used. It is
always best if unit can be stopped while grease is added to
avoid overloading.
NOTE: Excess grease is the most common cause of
overheating.
The bearing frame should be kept clean, since any
contamination of foreign matter which gets into the
housing will destroy bearings in a short time. When
cleaning bearings, use a bearing cleaning solvent, or an
industrial cleaning solvent. Do not use gasoline. Use lint
free cloths. Do not use waste rags.
A regular ball bearing grease should be used, but a standard
commercial vaseline can be substituted if necessary.
36
3498 IOM 12/04