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JAPAN ENGINE CORPORATIONSERVICE ENGINEERING DEPARTMENT, SERVICE ENGINEERING SECTION
1, MINAMIFUTAMI, FUTAMI-CHO, AKASHI-CITY 674-0093, JAPANTEL. +81-78-949-0804 (direct), e-mail: sales2@j-eng.co.jp (parts & engineer order), service@j-eng.co.jp (technical inquiry)

Subject :(1/6)

Application

UEC Diesel Engine

Type

All UEC
USI-10020E Rev.3

Notice for the compliant fuel oils 0.5% or less sulfur content

No.

If necessary
In order to reduce Sulfur Oxides(SOx) and Particular Matters(PM) emitted from ships, sulfur
content in fuel oils has been regulated by MARPOL 73/78 (International Convention for thePrevention of Pollutant from Ships) Annex VI-14.1.3. After January 1st 2015, the sulfur content
in fuel oils was regulated below 0.1% in the Emission Control Areas(ECA), and it was further
regulated globally below 0.5% from 3.5% after January 1st 2020 except for the above ECA.
This new regulation, applied for not only newly built ships but also in-service ones while theNOx regulation has been applied for newly built ones, will request all the ships using thefollowing measures to meet the regulation;
・Distillate fuel oils currently available in the market, such as MGO(Marine Gas Oil)or MDO(Marine Diesel Oil) having less than 0.5% sulfur content

・Compliant fuel oils specially provided with 0.5% or less sulfur content for this regulationas called VLSFO(Very Low Sulfur Fuel Oil)・

Proper treatment system or device, as defined EGCS (Exhaust Gas Cleaning System)

This service information describes how to apply the compliant fuel oils 0.5% or less sulfur
content, VLSFO.
It is recommended to refer below guideline and also relevant information/guidance issued byclassification society and/or concerned authorities.
・CIMAC Guideline： “Marine fuel handling in connection to stability and compatibility”
・Class NK： “Guidance for onboard use of Compliant Fuel Oil with SOx regulation from 2020”
・Lloyd’s Register： “Guidance for shipowners and operators on MARPOL Annex VI Sulphur Regulation.”

2012
MARPOL
Annex Ⅵ
（Regulation 14）

GlobalFig. 1

2020

3.5%

4.5%

SOx
ECA

2015

1.0%

0.5%

0.1%

Sulfur Content regulation by MARPOL【Remarks】
Marine fuel oils are specified by ISO8217 as Distillate Fuel(DM) and Residual Fuel(RM).
ISO8217 is being revised according to the new SOx regulation. Until ISO8217 will revised,Publicly Available Specification, ISO PAS23263 issued in September, 2019 is valid.
This PAS’s validity is limited in three years, a revised ISO8217 will be issued in 2022.

Plan record

The action priority indicated at the upper right corner is settled by Japan Engine Corporation originally and it does not decide the action of users.
Further, it is not guaranteed the every action carried out according to this service information.
The service information issued by Japan Engine Corporation included not only copyright but also all rights is reverted on Japan Engine Corporation.

Newly issued 29th Mar. 2019 (T.Y, T.N, K.I)
Rev.1 P3 correction of errors 4th Apr.2019(T.Y,
T.N, K.I)
Rev.2 Updated 24th Jan. 2020(T.Y, K.K, K.I)
Rev.3 P4 Updated 7th Jul. 2020

Approved

K. Yoshida

SERVICE ENGINEERING DEPARTMENT

Checked

H. Hirabayashi

ENGINEERING DEPARTMENT

Designed

K.Imanaka

DATE OF REVISED: 7th Jul. 2020

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(1) Important points when using compliant fuel oils

Compliant fuel oils with sulfur content of 0.5% or less, as defined compliant fuel oils, areexpected to supply to the market through various refinery processes blended by low sulfur baseoils. Their properties can have wide range by production area, oil company, and refinery plant.
Each bunker fuel may have different properties in extreme cases. When comparing theexisting residual fuel oils, compliant fuel oils are expected to have a wide variation with theirkinematic viscosity, cat-fines, ignition property, cold flow property and specific gravity, to thosespecial attentions paid.

1) Sulfur content
Sulfur in fuel oil forms Sulfur Oxides(SOx) when burned and will turn into sulfuric acid bycomposing with water in air. This is known as acid corrosion of combustion chambercomponents. To avoid acid corrosion (low temperature corrosion), cylinder oils containing
alkalinity, such as Base Number 100, are used to neutralize sulfuric acid. By reducing thesulfur content of fuel oil from 3.5% to 0.5% or less, composed sulfuric acid amount will
become smaller and the risk of sulfuric acid corrosion will tend to be less. Base Number ofcylinder oil shall be adjusted according to sulfur content of fuel oil to prevent from possible
negative effects, excessive hard deposit formation by chemical reaction of bases and fuel oil.
Thus, cylinder oil shall be selected having proper BN and good detergency and dispersancy.
(Refer to the service information USI-10004 ”Lubricating oil list for UEC engines” )2) Kinematic viscosity
Excessively high kinematic viscosity may result fuel pump damage due to excessive pressurerise, and cause improper fuel spray formation and poor combustion subsequently.
Considerably low viscosity can cause wear down of running surfaces of fuel pumpplunger/barrel and needle valve of fuel injection valve due to poor oil film formation. In theworst case, seizure can happen on the above engine components. Low viscosity can also
cause bigger fuel oil leakage from fuel pump and/or fuel injection valve, and the bigger fuel oil
leakage by wear-downed fuel pump plunger/barrel can result in engine starting failure.
Viscosity of compliant fuel oil may vary bunkering by bunkering, so it is necessary to monitor
that viscosity of each bunkering is controlled as specified. (recommended: between 3mm 2/sec
and 18mm2/sec, acceptable: between 2mm2/sec and 18mm2/sec)
Upper limit of fuel oil heating temperatures for UE engines is 150℃ and the lower is not
specified, however, cold flow property must be assured as mentioned later.
Thus, pay special attentions for the following items;
・In case automatic viscosity controller is equipped, it is very important to operate thecontroller by monitoring the viscosity. When re-bunkering, make sure that the controller
is working properly to adjust specified viscosity.

UE・In case of manually controlled viscosity controller, it is requested to set the temperature
manually after every bunkering to adjust the viscosity as specified referring
temperature-viscosity diagram. Reconfirmation using viscometer is also recommended.
If viscometer is not equipped, it is strongly recommended to install it.

・If lower viscosity(less than 2mm2/sec) is expected, fuel oil cooler or chiller shall be
provided to secure specified viscosity. Fuel oil shall be selected, when adjusting thetemperature, set the temperature (pour point + 10℃ to be targeted) to avoid waxing.
(Refer to the service information USI-10003 “Notice for Using Low Sulfur / Low Viscosity
Fuel Oil”)

・

When using low viscosity compliant fuel oil, there is a possibility that fuel supply pump
and/or booster pump cannot deliver the normal operating pressure due to inside leakageof the pumps. The leakage amount will differ by pump’s specification. When changing
fuel oils with lower viscosity one, engine inlet fuel oil pressure shall be watched.

・

Rapid fuel oil change may cause rapid temperature change, which can result seizure ofplunger/barrel of fuel pump. Temperature change speed shall be adjusted at 1～2℃
/min. not only for changing from distillate to residual oil but also changing with different
viscosity compliant fuel oils.

3) Cat Fines
Clarified Oil(CLO) which is fractionated by fluid catalytic cracking(FCC) is one of candidate of
low sulfur base oils. CLO is produced by filtration of FCC slurry to eliminate FCC fines(CatFine). If cat fines are not eliminated sufficiently, a lot of cat fines can remain in compliant fueloil. Cat fine has a diameter of 5～25μm and is composed of Aluminum/Silicon oxides with avery high hardness almost the same as abrasive powder and harder than steel. Once catfines intrude into the running surfaces of piston ring and cylinder liner, deep scratches can ruin
the cylinder oil film formation resulting in scuffing and gas blow-by. Excessive cylinder liner
wear may happen eventually.
Not only piston ring/cylinder liner but also fuelpump(plunger/barrel) and fuel injection valve(needle valve) can also be affected as shorter life
time due to abrasive of running surfaces. Piston stuffing box rings can be worn down due todamaged running surface of piston rod. This can be detected by increase of piston stuffing
box drain amount. Running conditions of piston ring/cylinder liner can be evaluated to acertain extent by analyzing piston under-side drain. Generally, Fe content of 50ppm or below
by analysis result is recognized in normal. Over 100ppm can be a sign of abrasive wear of
cylinder liner and inspection of fuel oil supply system and piston ring/cylinder liner isrecommended in the earliest opportunity.
(If sampling cock is not equipped on the piston under-side drain line, and drain sampling isnecessary, please contact us.)

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Upper limit of Al + Si content is specified in ISO8217. In ISO8217(2017), it is limited at
60ppm or less, however, recommendation for UE engines are less than 30ppm as bunker andless than 7ppm at engine inlet. If fuel oils containing high Al+Si are used, following actions
to be taken;
・Frequent drainage of settling tank and service tank (several times per day)・Run all the purifiers in-parallel with their minimum flow against their nominal capacities.
Keep the proper temperature based on the viscosity of the fuel to eliminate cat fines andimpurities. Use proper gravity disc according to fuel oil specific gravity.
(Please consult with purifier manufacturer in detail.)・

Use fuel oil filter(s) appropriately.

・

Back-wash drain oil of filter(s) should not be returned to engine.

Do not by-pass filter(s)Adequate pre-treatment will prevent from cat fine damages.
(Refer to the service information USI-10013 ” Prevention of inadaptability due to use of FCC
fuel oil”)
Just after changing storage tanks, relatively high-dense cat fines settled on the tank bottom
could be suctioned by transfer pump. In rough sea conditions, they might be circulated by hullswing. In these cases, it is known that back-washing interval becomes shorter than usual, andfuel oil conditions can be monitored. In those cases, use the fuel oils pre-treated properly by
the above treatment.

4) Ignition and combustion
Light Cycle Oil(LCO) is also a candidate of low sulfur base oils for compliant fuel oil together
with the said CLO. LCO and CLO contain a lot of Aromatics, and there is a possibility of poor
ignition and combustion property.
Slow speed two-stroke UE engines have an advantage for this matter thanks to longer
combustion duration. High/Middle speed engines are easily influenced by ignition, and poor
combustion at low load, such as diesel knocking, can happen.
ISO 8217 gives a guidance on this issue as CCAI(Calculated Carbon Aromatic Index).
Less than 850 is recommended for UE engines. Estimated Cetane Number(ECN), which is
calculated by FCA test, is also an effective index to evaluate ignition property of distillate andresidual fuels. (Refer to CIMAC “Fuel Quality Guide – Ignition and Combustion”)

5) Cold flow property
When using compliant fuel oil which is inferior in cold flow property, filter clogging by wax,
difficulty of transfer by solidification can limit fuel oil supply to engine resulting in output
shortage or engine stop. Once fuel oils are waxed, tremendous efforts, re-heating or removal
of sludge by hand will be required.

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Cold flow property is mainly defined by Pour Point(PP), it is generally recommended to heat thefuel oil at more than 10℃ above the PP. Cold Filter Plugging Point(CFPP) is also regarded as
an index to avoid filter plugging. Heating more than CFPP is recommended.
When using compliant fuel oils those do not require heating, proper fuel oil selection isnecessary so that PP is lower than operating temperature (atmospheric temperature, sea watertemperature, engine room temperature and lower limit of storage tank temperature) considering
the environmental conditions.

6) Specific gravity
As mentioned the above, compliant fuel oil may contain harmful cat fines, sufficient
pre-treatment by centrifugal purification is effective to eliminate cat fines. To operate
centrifugal purifier effectively, adjustment of gravity disk according to fuel oil specific gravity isimportant. If not, expected performance could not be obtained.

7) Stability and compatibility
Fuel oil stability has two definitions, Stability(self-stability) and Compatibility. Stability means
stableness against sludge formation after long term storage, and compatibility means how afuel oil is stable when mixing with different fuel oils.
Stability shall be considered by fuel oil supplier, it will be referred to future revision of ISO8217,
expected to issue in 2022. On the other hand, compliant fuel oils have wide variation ofproperties according to production area, oil company, refinery plant, and bunkering in utmost
case. It is practically impossible to secure compatibility for all compliant fuel oils, and fuel oil
suppliers have declared “Do not mix different compliant fuel oils”. Generally, mixing of fueloils mainly composed of aromatics and paraffin based fuel oils may form asphaltene sludge.
Sludge dispersant is sometimes used to avoid this problem. Consultation with additive agent
supplier is recommended. Deposited sludge might clog strainer and make transfer fromtank(s) difficult, and fuel pump plunger/barrel and fuel injection valve might be stuck.
Therefore, mixing of different fuel oils should be avoided. Even so, mixing is inevitable, selectfuel oils having similar fuel oil properties, specific gravity and PP. Before mixing, spottest(ASTM D4740) must be performed to secure compatibility.

Before changing fuel oil from conventional high sulfur residual fuel oil to compliant fuel oil, it isnecessary to clean the deposits in relevant tanks, pipes, and equipment. Deposits might containsludge and cat fines, and sufficient pre-treatment is required for the fuel oils used for flushing
before supplying to engine.

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(2) Engine modification for compliant fuel oil

Important points when using compliant fuel oils are mentioned as above section (1), but engine
modification is not required.
However, it is recommended to store reasonable number of spare parts, mainly fuel injection
system components (plunger/barrel, fuel injection valves etc.) to cope with unexpected cases.
As mentioned, properties of compliant fuel oils have not been fixed and they will have wide
variation. In near future, durable engine components, piston rings and fuel injection system,
might be requested against compliant fuel oils.
These components will be introduced
accordingly after ready to supply.