The viscosity of the fuel is significant because fuel
serves as a lubricant for the fuel system components.
Fuel must have sufficient viscosity in order to
lubricate the fuel system in both extremely cold
temperatures and extremely hot temperatures. If the
kinematic viscosity of the fuel is lower than 1.4 cSt at
the fuel injection pump damage to the fuel injection
pump can occur. This damage can be excessive
scuffing and seizure. Low viscosity may lead to
difficult hot restarting, stalling and loss of
performance. High viscosity may result in seizure of
the pump.
Perkins recommends kinematic viscosities of 1.4 and
4.5 mm2/sec that is delivered to the fuel injection
pump.
Density
Density is the mass of the fuel per unit volume at a
specific temperature. This parameter has a direct
influence on engine performance and a direct
influence on emissions. This determines the heat
output from a given injected volume of fuel. This is
generally quoted in the following kg/m at 15 °C
(59 °F).
Perkins recommends a value of density of 841 kg/m
in order to obtain the correct power output. Lighter
fuels are acceptable but these fuels will not produce
the rated power.
Sulfur
The level of sulfur is governed by emissions
legislations. Regional regulation, national regulations
or international regulations can require a fuel with a
specific sulfur limit. The sulfur content of the fuel and
the fuel quality must comply with all existing local
regulations for emissions.
Tables 25 and 26 list the guidelines for the correct
sulfur level for specific territories. Consult all
applicable regulations before selecting the fuel for a
given engine application.
Table 25
Territory Fuel Requirements from 2007
EPA
Low Sulfur (500 ppm) maximum
EC
Sulfur/Power Low sulfur (300
ppm) maximum
for less than or
equal to 19 kW
Sulphur (1000
ppm) maximum
for greater than
19 kW
Models 402D-05 and
403D-07
403D-11,
403D-15,
403D-15T,
403D-17,
404D-15.
404D-22,
404D-22T and
404D-22TA
Non-Regulated
Territories
Sulfur limit of less than 4000 ppm
Table 26
Territory Fuel Requirements from 2010
EPA
Ultra Low Sulfur (15 ppm) maximum
EC
Sulfur/Power Ultra Low sul-
phur (10 ppm)
maximum for
less than or
equal to 37 kW
Low sulphur
(300 ppm)
maximum for
greater than 37
kW
Models 402D-05,
403D-07,
403D-11,
403D-15,
403D-15T,
403D-17,
404D-15
404D-22,
404D-22T and
404D-22TA
Non Regulated
Territories
Sulfur limit of less than 4000 ppm
By using the test methods “ASTM D5453, ASTM
D2622, or ISO 20846 ISO 20884”, the content of
sulfur in low sulfur diesel (LSD) fuel must be below
500 PPM 0.05%. By using the test methods “ASTM
D5453, ASTM D2622, or ISO 20846 ISO 20884”, the
content of sulfur in ultra low sulfur (ULSD) fuel must
be below 15 PPM 0.0015%. The lubricity of these
fuels must not exceed wear scar diameter of
0.46 mm (0.0181 inch). The fuel lubricity test must
be performed on a HFRR, operated at 60 °C
(140 °F). Refer to “ISO 12156-1 ”.
In some parts of the world and for some applications,
high sulfur fuels above 0.5% by mass might only be
available. Fuel with very high sulfur content can
cause engine wear. High sulfur fuel will have a
negative impact on emissions of particulates. High
sulfur fuel can be used provided that the local
emissions legislation will allow the use. High sulfur
fuel can be used in countries that do not regulate
emissions.
When only high sulfur fuels are available, it will be
necessary that high alkaline lubricating oil is used in
the engine or that the lubricating oil change interval is
reduced. Refer to this Operation and Maintenance
Manual, “Fliud Recommendations (Genernal
Lubrication Information)” for information on sulfur in
fuel.
Lubricity
This is the capability of the fuel to prevent pump
wear. The fluid's lubricity describes the ability of the
fluid to reduce the friction between surfaces that are
under load. This ability reduces the damage that is
caused by friction. Fuel injection systems rely on the
lubricating properties of the fuel. Until fuel sulfur limits
were mandated, the fuel's lubricity was generally
believed to be a function of fuel viscosity.
46
SEBU8311-09
Maintenance Section
Fuel Specification
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