34 SEBU8191-01
Maintenance Section
Refill Capacities
Recommendatio
ns for B iodiesel
Biodiesel can be blended with distillate diesel fuel.
The blends can
be used as fuel. The most commonly
available biodiesel blends are B5, which is 5 percent
biodiesel and 95 percent distillate diesel fuel. B20,
which is 20 pe
rcent biodiesel and 80 percent distillate
diesel fuel.
Note: The pe
rcentages given are volume-based.
The U.S. distillate diesel fuel specification “ASTM
D975-09a” i
ncludes up to B5 (5 percent) biodiesel.
European distillate diesel fuel specification EN590:
2010 inclu
des up B7 (7 percent) biodiesel.
Specification Requirements
The neat biodiesel must conform to the latest
“EN14214 or ASTM D6751” (in the USA). The
biodiese
l can only be blended in mixture of up to
20% by volume in acceptable mineral diesel fuel
meeting latest edition of “EN590 or ASTM D975 S15”
designat
ion.
In United States Biodiesel blends of B6 to B20 must
meet the
requirements listed in the latest edition of
“ASTM D7467” (B6 to B20) and must be of an API
gravity of 30-45.
In North America biodiesel and biodiesel blends
must be purchased from the BQ-9000 accredited
produc
ers and BQ-9000 certified distributors.
In other areas of the world, the use of biodiesel
that i
s BQ-9000 accredited and certified, or that is
accredited and certified by a comparable biodiesel
quality body to meet similar biodiesel quality
stand
ards is required.
Engine Service Requirements
Aggressive properties of biodiesel fuel may cause
debris in the fuel tank and fuel lines to be released
and e
ntrained in the fuel. This effectively cleans
the fuel system. This cleaning of the fuel system
can prematurely block of the fuel filters. Perkins
rec
ommend that after the initial usage of B20
biodiesel blended fuel the fuel filters must be replaced
at 50 hours.
Glycerides present in biodiesel fuel will also cause
fuel filters to become blocked more quickly. Therefore
th
e regular service interval should be reduced to 250
hours.
•
Crankcase oil f
uel dilution can be higher when
biodiesel or biodiesel blends are used. This
increased level of fuel dilution when using biodiesel
or biodiesel b
lends is related to the typically
lower volatility of biodiesel. In-cylinder emissions
control strategies utilized in many of the industrial
latest engin
e designs may lead to a higher level
of biodiesel concentration in the sump. There is
recent evidence that the unburnt fuel can form
“treacle” l
ike deposits in the engine oil pan. If left to
accumulate the deposits have been shown to block
oil ways leading to engine failure. This reinforces
the need to o
perate a reduced oil change interval.
•
Perkins recommend the use of oil analysis in order
to check th
e quality of the engine oil if biodiesel
fuel is used. Ensure that the level of biodiesel in
the fuel is noted when the oil sample is taken.
Performance Related Issues
Duetothe
lower energy content than the standard
distillate fuel B20 will cause a power loss. In addition,
over time the power may deteriorate further due to
deposits
in the fuel injectors.
Biodiesel and biodiesel blends are known to cause
an incre
ase in fuel system deposits, most significant
of which are deposits within the fuel injector. These
deposits can cause a loss in power due to restricted
or modifi
ed fuel injection or cause other functional
issues associated with these deposits.
•
The eng
ine may be difficult to start in cold
conditions.
•
The tu
rbochargers may have a reduced service life.
•
The engine emissions can deteriorate.
General Requirements
Biod
iesel has poor oxidation stability, which can result
in long-term problems in the storage of biodiesel.
Biodiesel fuel should be used within 6 months of
manu
facture. Equipment should not be stored with
the B20 biodiesel blends in the fuel system for longer
than 3 months.
Due to poor oxidation stability and other potential
issues, it is strongly recommended that engines with
lim
ited operational time either not use B20 biodiesel
blends or, while accepting some risk, limit biodiesel
blend to a maximum of B5. Examples of applications
th
at should limit the use of biodiesel are the following:
Standby Generator sets and certain emergency
vehicles.
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