Goulds Pumps AF (Axial Flow) (42"/1200mm/54/60"/66") LM/LMR Bearings - IOM" - Manual (Page 41)

AF (42-66) IOM 41
OIL TYPE
A good SAE#30 or #40 is usually satisfactory. Consult
a reputable supplier for acceptable substitutes for the
oils mentioned. The viscosity of the oil should be 150
SSU at the operating temperature
to prevent
accelerated bearing wear 150
° F is the maximum
temperature at which a typical 30 wt. oil will supply the
required viscosity.
For the best results, the minimum oil viscosity should
be maintained as follows:
Operating temp. below 150
°F - SAE 30
Operating temp. 150 - 160
°F - SAE 40
Operating temp. 160 - 180
°F - SAE 50
An oil with a higher viscosity than required will increase
the bearing operating temperature because of the extra
viscous drag, but never to the point where the viscosity
becomes lower than required from the increased heat
generation. It is therefore better for the bearings to
have an oil that is too heavy rather than too light.
Change the oil after the first 200 hours of operation.
For normal operating conditions, change the oil at least
four (4) times a year. If the bearing assembly is
exposed to dirty or moist conditions, the oil should be
changed more often.
OIL LEVEL CONTROL
If the level of oil in the bearing housing (134C) is too
high, excessive heat may be generated due to
churning. If the level is too low, excessive heat may
be generated due to inadequate lubrication. A liquid
level switch connected to the oil sump can be used to
warn of a dangerous oil level condition.
Observe the oil level requirements shown on the
assembly drawing furnished with the pump. If
excessive heat is experienced within these levels,
consult the factory. Be sure that the shaft centerline is
horizontal through the bearing housing.
NORMAL BEARING TEMPERATURE
The running temperature for a bearing assembly
depends on many factors such as speed, bearing
loads, lubrication, ambient air temperatures, and
condition of bearings. Temperatures higher than the
human hand can tolerate are very satisfactory for
good bearing operation and should not cause any
alarm.
For a given speed and loading, the bearing housing
temperature will stabilize at some temperature, usually
below 200
°F., which will be the normal temperature for
the installation. Higher temperatures than this normal
temperature, without any change in speed or loading
can mean a lubrication difficulty or the approach of
bearing failure..
MAINTENANCE OF SHAFT SEALS
MECHANICAL SEAL
When mechanical seals are furnished, a
manufacturer’s reference drawing is supplied with the
data package. This drawing should be kept for future
use when performing maintenance and adjusting the
seal. The seal drawing will also specify required flush
liquid attachment points. The seal and all flush piping
must be checked and installed as needed prior to
starting the pump.
The life of a mechanical seal depends on various
factors such as cleanliness of the liquid handled and
its lubricating properties. Due to the diversity of
operating conditions it is, however, not possible to give
definite indications as to its life.
WARNING
Never operate the pump without liquid supplied to
the mechanical seal. Running a mechanical seal
dry, even for a few seconds, can cause seal
damage and must be avoided. Physical injury can
occur if the mechanical seal fails.
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