2.2 Fuel storage and pumping Onboard
? Learning Objectives The learning objectives of
this section are to make all engineers,engine
cadets and other crew members who are
involved in the handling of fuels onboard,
familiar with:
– How to handle the fuel.
– Take the necessary simple precautions by following
test procedures.
– To evaluate and find the correct temperatures of the
fuel related to storing and pumping.
– To undertake the correct operation when performing
stripping and trimming.
2.2 Fuel storage and pumping Onboard
Storage temperatures
1,In general,bunkers should be stored at
temperatures that allow reliable pumping
while preventing build-up of wax in tank
bottoms.
2,The use of bunker tanks for water ballast
should be avoided.
3,The storage tanks should be maintained at a
temperature that allows the fuel to be pumped
or moved by gravity,without undue difficulty.
4,A temperature of about 45℃ will normally
ensure good flow and pumping conditions.
Table 2.1 Heating requirements for pumping
the
2.2 Fuel storage and pumping Onboard
? Heating and cooling
1,Storage heating capacity should be capable of raising
the fuel temperatures to 45℃
2,With high pour point waxy fuels,the temperature
should not be allowed to approach the pour point,
Otherwise,when the fuel is reheated for pumping,
there may be great difficulties in remeling the wax
structures that have formed in the tank.
3,If the fuel has been allowed to cool however,
extended heating time may be needed to dissolve all
the wax in order to avoid filter blocking,
2.2 Fuel storage and pumping Onboard
? NOTE,fuel oils should never be heated to
more than 10℃ below the actual flash point,
Heating coils should extend all over the tank
bottom area to ensure that wax can be
dissolved,If heaters are situated at the
outflow only,wax may build up elsewhere in
the tank.
? Fuel tank heating coils,The storage tanks are
heated by means of steam,and two kinds of
leakage problems may occur,
2.2 Fuel storage and pumping Onboard
? Water is disappearing from the feed water
system,If water disappears from the feed water
system,Check for steam leakage in the visible
system,If not found,the leakage may be inside
one of the tanks,which means that steam is
leaking into the fuel oil,The process of locating
the leakage will be very time consuming,and
when located,that particular part of the
heating system must be isolated,The result
may be that the fuel in the actual tank will be
difficult to handle because of the lack of
heating,
2.2 Fuel storage and pumping Onboard
? Oil is spotted in the feed water,If oil is spotted in the
feed water,Lack of maintenance of the heating system
may cause leakage,which means that fuel oil is leaking
into the heating system,It is possible to discover this
kind of leakage by performing regular inspections of
the cascade tank water,steam traps,etc,at the suction
side of the pumps,The process of locating the leakage
will be very time consuming,and when located,the
actual part of the heating system must be isolated,The
result may be that the fuel in the actual tank will be
difficult to handle because of lack of
heating.Maintenance and regular inspection of the fuel
tank heating systems must be considered as good
economy,
2.2 Fuel storage and pumping Onboard
? Bunker segregation plan All ships should
have a plan for segregation of fuel oil in
order to:
? Prevent usage of fuel until test results are
received
? Always keep track of the fuels
? Prevent accidental mixing of non-
compatible fuels
2.2 Fuel storage and pumping Onboard
? Tank to tank operations
– Cleaning intervals of tanks:
All ships should have a plan for cleaning intervals of
fuel tanks,The fuel tanks should normally be cleaned
during every docking,Nevertheless it must be an
established routine to carry out tank inspections,in -
between dockings.
– Sediments and rough weather mixing:
Water and sediments already settled in the tanks,
are likely to be mixed back into the fuel,when
sailing with slack tanks in rough weather,If this
occurs in the settling tank,the fuel should be
given a prolonged settling period,if possible
before being transferred to the service tank,
If an emulsion should occur,it may be possible
to dissolve this by adding certain additives to
the fuel,but only if advised to do so from head
office.
2.2 Fuel storage and pumping Onboard
2.2 Fuel storage and pumping Onboard
– New fuel to settling tank:
Fuel oils should never be mixed!
When transferring fuel from bunker
tanks to settling tank,it is preferable
to transfer to an empty settling tank,If
the settling tank is not empty,great
attention must be paid to the degree of
compatibility of the mixed fuel oils,
2.2 Fuel storage and pumping Onboard
– Stripping,To be able to strip a bunker tank
completely,it may both be necessary to trim
and list the ship,If possible,avoid trimming
by fuel,Trimming by ballast water is the
correct action,If it is necessary to trim by fuel,
avoid the mixing of fuels.
– Filtration from bunker - to settling tanks:
The filters used are coarse-meshed,The mesh
size varies from 0.5-5mm,depending on the
pumps it is designed to protect,These filters
are used to pick up solids,such as rust flakes,
etc.,which may damage the pumps,
2.2 Fuel storage and pumping Onboard
– Sampling and test results
Routines or selective sampling within the
fuel treatment system,will provide useful
indication of the performance of the fuel
treatment system,Density,viscosity,
CCAI,water content and compatibility
should be checked by use of the kit
onboard.
2.2 Fuel storage and pumping Onboard
– Test results,The samples taken during
bunkering are sent,normally to FOBAS or
DNVPS (Det Norske Veritas Petroleum
Services)for analysis,The actual fuels shall
not be used until the test results are received
onboard,Under normal circumstances this
will take about four to five days.
– Off spec,fuel,When test results are received,
always follow the advice given by FOBAS or
DNVPS,
Table 2.2 Mixing of fuels
2.2 Fuel storage and pumping Onboard
? Potential sludge forming tendency as a result
of incompatibility between a residual and a
distillate fuel.
– Mixing of fuels If it is not possible to avoid fuel
mixing,try to avoid mixing of fuels from different
sources,If you must mix,avoid equal proportions,
Two fuels of essentially the same density may be
mixed,with a minimum risk of incompatibility,If
different fuels must be mixed in a tank,the chances
of incompatibility may be minimized by reducing
the amount of one fuel to a minimum,before
adding the other fuels to the tank,
2.2 Fuel storage and pumping Onboard
? Fuel additives There are several chemical
additives for use in the fuel oil on board,The
most common areas for use are:
– 1,Additives for retardation of sludge settling in
the bunker tanks.
– 2,Additives for changing the temperature
relations between vanadium and sodium
– 3.Additives for increasing the combustion
performance
– 4,Emulsion breakers
Remeber,Chemical additives are not to be used
onboard,unless advised to do so by the head office.
? Learning Objectives The learning objectives of
this section are to make all engineers,engine
cadets and other crew members who are
involved in the handling of fuels onboard,
familiar with:
– How to handle the fuel.
– Take the necessary simple precautions by following
test procedures.
– To evaluate and find the correct temperatures of the
fuel related to storing and pumping.
– To undertake the correct operation when performing
stripping and trimming.
2.2 Fuel storage and pumping Onboard
Storage temperatures
1,In general,bunkers should be stored at
temperatures that allow reliable pumping
while preventing build-up of wax in tank
bottoms.
2,The use of bunker tanks for water ballast
should be avoided.
3,The storage tanks should be maintained at a
temperature that allows the fuel to be pumped
or moved by gravity,without undue difficulty.
4,A temperature of about 45℃ will normally
ensure good flow and pumping conditions.
Table 2.1 Heating requirements for pumping
the
2.2 Fuel storage and pumping Onboard
? Heating and cooling
1,Storage heating capacity should be capable of raising
the fuel temperatures to 45℃
2,With high pour point waxy fuels,the temperature
should not be allowed to approach the pour point,
Otherwise,when the fuel is reheated for pumping,
there may be great difficulties in remeling the wax
structures that have formed in the tank.
3,If the fuel has been allowed to cool however,
extended heating time may be needed to dissolve all
the wax in order to avoid filter blocking,
2.2 Fuel storage and pumping Onboard
? NOTE,fuel oils should never be heated to
more than 10℃ below the actual flash point,
Heating coils should extend all over the tank
bottom area to ensure that wax can be
dissolved,If heaters are situated at the
outflow only,wax may build up elsewhere in
the tank.
? Fuel tank heating coils,The storage tanks are
heated by means of steam,and two kinds of
leakage problems may occur,
2.2 Fuel storage and pumping Onboard
? Water is disappearing from the feed water
system,If water disappears from the feed water
system,Check for steam leakage in the visible
system,If not found,the leakage may be inside
one of the tanks,which means that steam is
leaking into the fuel oil,The process of locating
the leakage will be very time consuming,and
when located,that particular part of the
heating system must be isolated,The result
may be that the fuel in the actual tank will be
difficult to handle because of the lack of
heating,
2.2 Fuel storage and pumping Onboard
? Oil is spotted in the feed water,If oil is spotted in the
feed water,Lack of maintenance of the heating system
may cause leakage,which means that fuel oil is leaking
into the heating system,It is possible to discover this
kind of leakage by performing regular inspections of
the cascade tank water,steam traps,etc,at the suction
side of the pumps,The process of locating the leakage
will be very time consuming,and when located,the
actual part of the heating system must be isolated,The
result may be that the fuel in the actual tank will be
difficult to handle because of lack of
heating.Maintenance and regular inspection of the fuel
tank heating systems must be considered as good
economy,
2.2 Fuel storage and pumping Onboard
? Bunker segregation plan All ships should
have a plan for segregation of fuel oil in
order to:
? Prevent usage of fuel until test results are
received
? Always keep track of the fuels
? Prevent accidental mixing of non-
compatible fuels
2.2 Fuel storage and pumping Onboard
? Tank to tank operations
– Cleaning intervals of tanks:
All ships should have a plan for cleaning intervals of
fuel tanks,The fuel tanks should normally be cleaned
during every docking,Nevertheless it must be an
established routine to carry out tank inspections,in -
between dockings.
– Sediments and rough weather mixing:
Water and sediments already settled in the tanks,
are likely to be mixed back into the fuel,when
sailing with slack tanks in rough weather,If this
occurs in the settling tank,the fuel should be
given a prolonged settling period,if possible
before being transferred to the service tank,
If an emulsion should occur,it may be possible
to dissolve this by adding certain additives to
the fuel,but only if advised to do so from head
office.
2.2 Fuel storage and pumping Onboard
2.2 Fuel storage and pumping Onboard
– New fuel to settling tank:
Fuel oils should never be mixed!
When transferring fuel from bunker
tanks to settling tank,it is preferable
to transfer to an empty settling tank,If
the settling tank is not empty,great
attention must be paid to the degree of
compatibility of the mixed fuel oils,
2.2 Fuel storage and pumping Onboard
– Stripping,To be able to strip a bunker tank
completely,it may both be necessary to trim
and list the ship,If possible,avoid trimming
by fuel,Trimming by ballast water is the
correct action,If it is necessary to trim by fuel,
avoid the mixing of fuels.
– Filtration from bunker - to settling tanks:
The filters used are coarse-meshed,The mesh
size varies from 0.5-5mm,depending on the
pumps it is designed to protect,These filters
are used to pick up solids,such as rust flakes,
etc.,which may damage the pumps,
2.2 Fuel storage and pumping Onboard
– Sampling and test results
Routines or selective sampling within the
fuel treatment system,will provide useful
indication of the performance of the fuel
treatment system,Density,viscosity,
CCAI,water content and compatibility
should be checked by use of the kit
onboard.
2.2 Fuel storage and pumping Onboard
– Test results,The samples taken during
bunkering are sent,normally to FOBAS or
DNVPS (Det Norske Veritas Petroleum
Services)for analysis,The actual fuels shall
not be used until the test results are received
onboard,Under normal circumstances this
will take about four to five days.
– Off spec,fuel,When test results are received,
always follow the advice given by FOBAS or
DNVPS,
Table 2.2 Mixing of fuels
2.2 Fuel storage and pumping Onboard
? Potential sludge forming tendency as a result
of incompatibility between a residual and a
distillate fuel.
– Mixing of fuels If it is not possible to avoid fuel
mixing,try to avoid mixing of fuels from different
sources,If you must mix,avoid equal proportions,
Two fuels of essentially the same density may be
mixed,with a minimum risk of incompatibility,If
different fuels must be mixed in a tank,the chances
of incompatibility may be minimized by reducing
the amount of one fuel to a minimum,before
adding the other fuels to the tank,
2.2 Fuel storage and pumping Onboard
? Fuel additives There are several chemical
additives for use in the fuel oil on board,The
most common areas for use are:
– 1,Additives for retardation of sludge settling in
the bunker tanks.
– 2,Additives for changing the temperature
relations between vanadium and sodium
– 3.Additives for increasing the combustion
performance
– 4,Emulsion breakers
Remeber,Chemical additives are not to be used
onboard,unless advised to do so by the head office.
