Sampling of lube oil should be done the following the
batch method and the other is the continuous
directions of NSTM Chapter 262 and shipboard PMS.
method.
procedures. When conducting shipboard tests, you should
follow the sampling procedures listed in Naval
BATCH METHOD.--In the batch process,
Ships' Technical Manual, chapter 262, beginning
the LO is transferred from the sump to a settling
at paragraph 262-8.1.22. After testing is com-
tank. The oil is heated in the settling tank.
pleted, deposit lightly contaminated oil into the
There its temperature is maintained at 1605F
LO settling tank for purification and reuse. Place
for 2190 TEP for several hours by steam-heating
grossly contaminated samples in the contaminated
coils or electric heaters. Water and other
impurities are stripped from the settling tank
through a drain valve. The oil is then cen-
trifuged and returned to the sump from which
it was taken. Alternatively, oil may be transferred
from the sump to a settling tank. You can
replenish the sump tank with clean oil immediately
by transferring oil from the storage tank via the
purifier. After the oil in the settling tank has
been heated, allowed to settle, and then stripped,
it is centrifuged and transferred back to the
storage tank.
CONTINUOUS METHOD.--In the continuous
purification process, the centrifugal purifier takes
suction from a sump tank and, after purifying the
oil, discharges it back to the same sump. As the
oil passes through a heater, its temperature is
raised to the correct level. All oil must be returned
to the sump from which it was taken. All ships
with forced lube systems equipped with centrifugal
purifiers will operate the purifiers while underway
until no visible water remains in the oil and no
water is discharged from the purifier. Generally,
the MRG lube oil system must be purified 12
hours daily. On gas turbine ships the CRP oil must
be purified for 8 hours, with the remaining 4 hours
of the day reserved for cleaning the purifier.
When the main propulsion equipment is
secured, the LO should be purified until no water
is discharged from the purifier. Also, all oil in the
lube system should be pumped to the settling tanks
and renovated each year.
Sampling of Lube Oil
When monitoring LO, you must sample the
oil properly because an improper sample produces
unreliable test results. You should be sure
your samples are representative of the oil you
are testing. Thoroughly clean and inspect the
sampling containers. Before using the containers,
flush them with the oil to be sampled. Cap all
sample containers promptly after sampling to
prevent contamination.
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