IHI NIIGATA MG(L)26HLX, Инструкция по эксплуатации

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S E C T I O N 1 - O U T L I N E
1.3 LUBRICATING OIL SPECIFICATIONS
１－３－０３
1.3.4 Tolerances in Lubricating Oil Properties
（
1) Viscosity: Viscosity generally increases with operating time. although
could instead decrease because of fuel dilution or addition of makeup oil.
The acceptable limits of viscosity change are + 30% or - 20% from the value
of the oil when new. Viscosity should never exceed 120 mm
2
/S (at 50
℃
)
maximum value.
If only the viscosity reaches the limiting value (and the other criteria
listed below are still within acceptable limits), it is permitted to add SAE
30 oil to reduce the viscosity level. However, this should be followed-up
with an immediate oil analysis to determine the cause of the viscosity
increase.
Moisture: The presence of water in the lube oil can indicate leaking oil
coolers, leaking aftercoolers, condensation,or failed gasket joints. Traces
of moisture are inevitable, but total moisture content should not exceed 0.3
% by volume. Centrifuging is desirable to keep water content to a minimum.
If the water content exceeds 0.5% by volume, immediate action should be
taken to (a) adjust the operation of the centrifuge to lower the water
content and (b) to determine and repair the source of water entry into the oil.
(2) Pentane Insoluable Content: Should not exceed 1.5% maximum.
(3) Toluene Insoluble Content: Should not exceed 1.0% maximum.
(4) Base Number: (ASTM:D2896 JIS:K2501)
Light Fuel Oil- TBN should not be lower than 6
Heavy Fuel Oil- TBN should not be lower than 15
As discussed in the section dealing with "Selection of Lubricating Oil", the
desired TBN of new oil depends upon the sulfur content of the fuel that is
being used. TBN typically decreases with hours of use and low values
indicate that the additives are no longer effective and a complete oil
change is advisable.
Flash Point: If the flash point value drops more than 50
℃
.
from the value of new oil, fuel dilution is indicated and remedial
action should be taken to determine the cause. With a flash-point lower than
150
℃
the chances of a crankcase explosion are increased.