Operation and maintenance manual

82 SEBU8601-01
Maintenance Section
Refill Capacities
Table 20
Acceptable Fuel Specification for the 1200 Series of Engines
(1)
Fuel Specification Comments
EN590 European Automotive Diesel Fuel (DERV)
“ASDM D975 G
RADE 1D S15”
“North Amer
ican Light Distillate Diesel fuel with less than 15
PPM sulfur level”
“ASTM D975 GRADE 2D S15” “North American Middle Distillate general purpose Diesel fuel
with less than 15 PPM sulfur level”
“JIS K2204” “Japanese D iesel Fuel” Must meet the requirements that are
stated in the section “Lubricity”.
“BS 2869: 2010 CLASS A2 or EU equivalent ” “EU Off Road Diesel fuel. Acceptable from 2011 MUST have
less than 1
0 PPM sulfur level”
(1)
All the fu
els must comply with the specification in the table for the Perkin s Specification Distillate Diesel F uel.
Diesel Fu
el Characteristics
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 t
o “ISO 5165” for the test method.
Cetane numbers in excess of 45 are normally
expect
ed 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 c
an have a low cetane value. A minimum cetane
value of 40 is required during average starting
conditions. A fuel with higher cetane number is
recom
mended for operations at high altitudes or in
cold-weather operations.
Fuel
with a low cetane number can be the root cause
of problems during a cold start.
Visc
osity
Viscosity is the property of a liquid of offering
res
istance to shear or flow. Viscosity decreases
with increasing temperature. This decrease in
viscosity follows a logarithmic relationship for normal
fos
sil fuel. The common reference is to kinematic
viscosity. Kinematic viscosity is the quotient of the
dynamic viscosity that is divided by the density. The
de
termination of kinematic viscosity is normally by
readings from gravity flow viscometers at standard
temperatures. Refer to “ISO 3104” for the test
me
thod.
The visco
sity 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
injecti
on pump, damage to the fuel injection pump
can occur. This damage can be excessive scuffing
and seizure. Low viscosity may lead to difficult hot
restar
ting, stalling, and loss of performance. High
viscosity may result in seizure of the pump.
Perkin
s recommends kinematic viscosities of 1.4 and
4.5 mm2/sec that is delivered to the fuel injection
pump. If a fuel with a low viscosity is used, cooling of
the fu
el 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 in order to lower
the vi
scosity 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
dire
ct influence on engine performance and a direct
influence on emissions. This influence determines
from a heat output given injected volume of fuel. This
par
ameter is quoted in the following kg/m
3
at 15 °C
(59 °F).
Per
kins recommends a density of 841 kg/m
3
in order
to obtain the correct power output. Lighter fuels are
acceptable but these fuels will not produce the rated
po
wer.
Sulfur
The level of sulfur is governed by emissions
legislations. Regional regulation, national regulations,
o
r international regulations can require a fuel with
aspecific sulfur limit. The sulfur content of the fuel
and the fuel quality must comply with all existing local
r
egulations for emissions.