Perkins 904D-E28T Operation And Maintenance Manual page 58

58
Maintenance Section
General Fuel Information
NOTICE
Operating with fuels that do not meet the Perkins rec-
ommendations can cause the following effects: Start-
ing difficulty, poor combustion, deposits in the fuel
injectors, reduced service life of the fuel system, de-
posits in the combustion chamber and reduced serv-
ice life of the engine.
Engines that are manufactured by Perkins are certi-
fied with the fuel that is prescribed by the United
States Environmental Protection Agency. Engines
that are manufactured by Perkins are certified with
the fuel that is prescribed by the European Certifica-
tion and other regulatory agencies. Perkins does not
certify diesel engines on any other fuel.
Note: The owner and the operator of the engine has
the responsibility of using the fuel that is prescribed
by the Environmental Protection Agency (EPA) and
other appropriate regulatory agencies.
Diesel Fuel Characteristics
Perkins Recommendations
Cetane Number
Fuel that has a high cetane number will give a shorter
ignition delay. A high cetane number will produce a
better ignition quality. Cetane numbers are derived
for fuels against proportions of cetane and
heptamethylnonane in the standard CFR engine.
Refer to "ISO 5165" for the test method.
Cetane numbers more than 45 are normally expected
from current diesel fuel. However, a cetane number
of 40 may be experienced in some territories. The
United States of America is one of the territories that
can have a low cetane value. A minimum cetane
value of 40 is required during average starting
conditions. A higher cetane value may be required for
operations at high altitudes or in cold-weather
operations.
Fuel with a low cetane number can be the root cause
of problems during cold start.
Viscosity
Viscosity is the property of a liquid of offering
resistance to shear or flow. Viscosity decreases with
increasing temperature. This decrease in viscosity
follows a logarithmic relationship for normal fossil
fuel. The common reference is to kinematic viscosity.
Kinematic viscosity is the quotient of the dynamic
viscosity that is divided by the density. The
determination of kinematic viscosity is normally by
readings from gravity flow viscometers at standard
temperatures. Refer to "ISO 3104" for the test
method.
The viscosity of the fuel is significant because fuel
serves as a lubricant for the fuel system components.
Fuel must have sufficient viscosity to lubricate the
fuel system in both cold temperatures and 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 cSt that is delivered to the fuel injection pump. If a
fuel with a low viscosity is used, cooling of the fuel
may be required to maintain 1.4 cSt or greater
viscosity at the fuel injection pump. Fuels with a high
viscosity might require fuel heaters to lower the
viscosity to 4.5 cSt at 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 influence determines
the heat output from a given injected volume of fuel.
This parameter is quoted in the following kg/m3 at
15 °C (59 °F).
Perkins recommends a value of density of 841 kg/m3
to obtain the correct power output. Lighter fuels are
acceptable but these fuels will not produce the rated
power.
Sulfur
Sulfur levels in the fuel affect the durability of engine
components and also affect engine exhaust
emissions. 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.
Low sulfur diesel (LSD) fuel with less than 0.05
percent (≤ 500 ppm (mg/kg)) sulfur is recommended
for use in these engine models
ULSD less than 0.0015% (≤15 PPM (mg/Kg)) sulfur
is acceptable to use in these engine models. The
lubricity of these fuels must not exceed wear scar
diameter of 0.52 mm (0.02047 inch) as per "ISO
12156-1". Refer to "Lubricity" for more information.
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