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.
Lubricity
Lubricity is the capability of the fuel to prevent pump
wear. The fluids 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 fuels lubricity was generally
believed to be a function of fuel viscosity.
The lubricity has particular significance to the current
low sulfur fuel, and low aromatic fossil fuels. These
fuels are made in order to meet stringent exhaust
emissions.
The lubricity of these fuels must not exceed wear
scar diameter of 0.52 mm (0.0205 inch). The fuel
lubricity test must be performed on an HFRR,
operated at 60 °C (140 °F). Refer to “ISO 12156-1 ”.
NOTICE
The fuels system has been qualified with fuel having
lubricity up to 0.52 mm (0.0205 inch) wear scar diam-
eter as tested by “ISO 12156-1”. Fuel with higher
wear scar diameter than 0.52 mm (0.0205 inch) will
lead to reduced service life and premature failure of
the fuel system.
Fuel additives can enhance the lubricity of a fuel.
Contact your fuel supplier for those circumstances
when fuel additives are required. Your fuel supplier
can make recommendations for additives to use, and
for the proper level of treatment.
Distillation
Distillation is an indication of the mixture of different
hydrocarbons in the fuel. A high ratio of light weight
hydrocarbons can affect the characteristics of
combustion.
Classification of the Fuels
Diesel engines have the ability to burn wide variety of
fuels. The following list of typically encountered fuel
specifications that have been assessed as to their
acceptability and are divided into following
categories:
Group 1: Preferred fuels
Following fuel specifications are considered
acceptable
• Fuels meeting the requirements of the "Perkins
Specification for Distillate Diesel Fuel" listed in the
Table 8 .
• EN590 - Grades A to F and class 0 to 4
• ASTM D975 Grade No. 1-D and 2-D
• JIS K2204 Grades 1, 2 & 3 & Special Grade 3
acceptable provides lubricity ware diameter does
not exceed of 0.46 mm (0.01811 inch) “ISO
12156-1 ”
• BS2869-Class A2 Off Highway Gas Oil, Red
Diesel
Note: 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 the lubricity section
within the Fuel Recommendation Section.
Group 3 Biodiesel Fuel
Recommendation for Biodiesel
Biodiesel is a fuel that can be defined as mono-alkyl
esters of fatty acids. Biodiesel is a fuel that can be
made from various feedstock. The most commonly
available biodiesel in Europe is Rape Methyl Ester
(RME). This biodiesel is derived from rapeseed oil.
Soy Methyl Ester (SME) is the most common
biodiesel in the United States. This biodiesel is
derived from soybean oil. Soybean oil or rapeseed oil
are the primary feedstocks. These fuels are together
known as Fatty Acid Methyl Esters (FAME).
Raw pressed vegetable oils are NOT acceptable for
use as a fuel in any concentration in compression
engines. Without esterification, these oils solidify in
the crankcase and the fuel tank. These fuels may not
be compatible with many of the elastomers that are
used in engines that are manufactured today. In
original forms, these oils are not suitable for use as a
fuel in compression engines. Alternate base stocks
for biodiesel may include animal tallow, waste
cooking oils, or various other feedstocks. In order to
use any of the products that are listed as fuel, the oil
must be esterified.
Fuel made of 100 percent FAME is generally referred
to as B100 biodiesel or neat biodiesel.
Biodiesel can be blended with distillate diesel fuel.
The blends can be used as fuel. The most commonly
available biodiesel blends are B7, which is 7 percent
biodiesel and 95 percent distillate diesel fuel. B20,
which is 20 percent biodiesel and 80 percent distillate
diesel fuel.
Note: The percentages given are volume-based.
The U.S. distillate diesel fuel specification “ASTM
D975-09a” includes up to B7 (7 percent) biodiesel.
European distillate diesel fuel specification EN590:
2010 includes up B7 (7 percent) biodiesel.
SEBU8731-04
59
Maintenance Section
Fuel Specification
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