Flowserve LNN - Manual (Page 28)

LNN, LNNV, LNNC USER INSTRUCTIONS ENGLISH 71569074 06-14
Page 28 of 56
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d) Press grease into the bearing housing until the
first signs of it appear in the gap between the
housing and shaft, then stop greasing.
e) V-rings should be seated at the proper distance
from the sealing surface to avoid overheating.
f) The maximum allowable operating temperatures
for anti-friction bearings will vary from unit to unit,
depending on ambient and fluid temperature.
The rise above ambient should not normally
exceed
55  C (99  F) or a combined maximum of
95  C (204  F).
g) A continuously rising temperature or an abrupt
temperature rise indicates a problem. If these
symptoms occur, stop the pump immediately and
investigate the cause.
TIME
T
EM
PER
AT
U
R
E
Grease change - every 4 000 hours or sooner
depending on the severity of the application.
a) Remove the bearing housing from the rotor
assembly.
b) Brush the bearing housing with hot kerosene (100
to 115 °C/212 to 240 °F) or other non-toxic solvent.
c) Clean and flush out the housing with a light
mineral oil.
d) Do not use waste oil to clean the housing.
To clean the bearings:
a) Wipe off as much grease as possible with a clean
lint-free cloth.
b) Brush bearings with hot kerosene (80 to 90 °C/ 175 to
195 °F) while gently spinning the outer bearing ring.
c) Spin each ball to ensure that it is clean.
To remove badly oxidized grease that refuses to
come off:
a) Support the rotor in a vertical position and
immerse the bearing in hot kerosene or a mixture
of alcohol and light mineral solvent.
b) Gently spin the bearing outer ring.
c) Dry and reflush the bearing with clean light oil.
d) It is important not to under or over grease the
bearings as this will lead to overheating and
premature failure. It is recommended that the
bearings be filled with grease using a suitable
spatula. In addition the housings should be no
more than half filled.
6.2.4
Mechanical seals
No adjustment is possible. When leakage reaches
an unacceptable level the seal will need replacement.
6.2.5
Gland packing
The stuffing box split gland can be completely
removed for re-packing or to enable the addition of
extra rings of packing.
The stuffing box is normally supplied with a lantern
ring to enable a clean or pressurized flush to the
centre of the packing. If not required, this can be
replaced by an extra two rings of packing.
There must always be a small leakage, normally a
minimum of 120 drops per minute to atmosphere to
lubricate and cool the packing is required.
6.2.6
Internal coating
If the pump has an internal coating, this coating must
be inspected periodically. Any wear or cracks of the
coating found must be immediately repaired. Failure
to do this may lead to accelerated wear of the coating
during operation and corrosion of the exposed base
metal, depending on the material and pumped liquid.
Special attention must be paid to the coating edges.