Xylem 9100 Series Base Mounted Centrifugal Fire Pumps AC8585 REV.C - Manual (Page 25)

MAINTENANCE
1. GENERAL MAINTENANCE
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 condition, and prevent costly
breakdown.
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.
2. MAINTENANCE OF PUMP DUE TO FLOOD
DAMAGE
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.
Mechanical seals should be cleaned and
thoroughly flushed.
Couplings should be dismantled and
thoroughly cleaned.
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.
3. BEARING 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 over-heating.
A lithium based NLGI-2 grade grease should
be used for lubricating bearings where the
ambient temperature is above -20°F. Grease
lubricated bearings are packed at the factory
with Shell Alvania No 2. Other recommended
greases are Texaco Multifak No. 2 and
Mobilux No. 2 grease.
Greases made from animal or vegetable oils
are not recommended due to the danger of
deterioration and forming of acid. Do not use
graphite. Use of an ISO VG 100 mineral base
oil with rust and oxidation inhabitors is
recommended.
The maximum desirable operating
temperature for ball bearings is 180°F.
Should the temperature of the bearing frame
rise above 180°F, the pump should be shut
down to determine the cause.
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