6 Maintenance
6.1 Bearing Maintenance
For ATEX applications bearing replacement (all) is recommended after 25,000 hours of operation.
6.1.1 Bearing Temperatures
WARNING:
These bearing lubrication sections list different temperatures of the pumped fluid. If the
pump is ATEX-certified and the temperature of the pumped fluid exceeds the permitted temper-
ature values, then consult your ITT representative.
All bearings operate at some temperature above that of the surrounding atmosphere, unless cooled.
Heat is generated within the bearing due to rolling friction, churning of oil and the "drag" of the race.
Do not use the human hand as a thermometer. A temperature which feels "hot" varies from 49°C to 53°C
| 120° F - 130°F, depending upon the individual. Above this temperature, the human hand is worthless in
estimating temperature.
Bearing temperatures up to 82°C | 180°F are normal. Determine the temperature accurately by placing a
contact type thermometer against the bearing housing. It should be recorded in a convenient location for
reference. The stability of the temperature, rather than the number of degrees is the best indication of
normal operation. A sudden increase in temperature is an indication of danger and a sign al to investi-
gate. The unit should be checked for abnormal hydraulic operation and unnecessary loads, such as cou-
pling misalignment, etc.
6.1.2 Bearing Inspection
•
Ball and Roller Bearings
Ball and roller bearings can be checked for visible wear by slowly turning the races and watching
for pits or worn areas on the balls, rollers or raceways. The bearings can also be inspected by hold-
ing the inner race and spinning the outer race. If any rasping noises are emitted or the bearing
"catches", it should be replaced. If any wear on the races is apparent, replacement is suggested.
•
Sleeve Bearing
Sleeve bearings should be inspected to determine if any deep scratches or gouges (other than oil
grooves) are present. The babbitted surfaes should also be free of high or low spots. Unless these
surfaces are completely smooth, they should be replaced if they cannot be "scraped in."
6.1.3 Clean the Bearings
The life of a bearing can be drastically reduced if contaminated with even a small amount of dust or dirt.
All bearing assembly operations should be done in as dust-free an atmosphere as possible. All tools, as
well as the hands, should be kept clean.
1.
If new bearings are to be installed, they should not be unwrapped until ready for installation and
should not be cleaned or washed.
2.
If old bearings are dirty, they should be replaced. Washing the bearings does not guarantee cleanli-
ness and is risky at best. If new bearings are not readily available, and immediate reassembly is
necessary, dirty bearings can be cleaned as follows:
a) Pour one or two quarts of clean, water-free kerosene into a clean pail.
b) Dip the bearings into the kerosene and agitate slowly.
6 Maintenance
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3175 Installation, Operation and Maintenance Instructions
