1. What does the fuel piping system comprise?

The fuel piping system comprises the fuel supply lines, high-pressure fuer lines and
fuel heating pipes, if heavy fuel is used. In the system the oil is stored in tanks in the
double bottom from which it is pumped to a settling tank and heated.

After passing through centrifuges the cleaned, heated oil is pumped to a daily
service tank. From the daily service tank, the oil flows through a three-way valve to
a mixing tank. A flowmeter is fitted into the system to indicate fuel consumption.
Booster pumps are used to pump the oil through heaters and a viscosity regulator to
the engine deven fuel pumps. The fuel pumps will discharge high pressure fuel to
their correspond injectors. Viscosity meter helps to measure density of fuel oil. The
viscosity regulator controls the fuel oil temperature in order to provide the correct
viscosity for combustion. A pressure regulating valve ensures a constant pressure
supply to the engine driven pumps, and a pre warming bypass is usen to heat up the
tuel before starting the engine.

2. What type of fuel is the most widely used?

The engine can be started up and maneuvered on masine diesel oil (MDO) or even a
blend of diesel and heavy fuel oil (FO). We use heavy fuel because it is cheap,
productive and can be used and stored for a long time

3. What is the function of fuel oil?

Onboard ships, Heavy Fuel Oil (HFO) is crucial for powering engines and maintaining
operations. The handling and preparation of HFO start with bunkering, where the
fuel is loaded onto the ship and stored in dedicated storage tanks. Also we have
such functions
Main Engine Power - used in marine diesel or steam turbine plants to propel the
ship.
Power supply - used in shipboard boilers and generators to generate electricity.
Heating and auxiliary systems - can be used in heating systems, fuel heating and
other technical needs.
Because fuel oil is highly viscous, it requires heating before being fed into the fuel
system. Modern ships can also switch to more environmentally friendly fuels, such
as low-sulphur marine fuels.

4. What fuel can be polluted with?

Fuel may loose his properties to such aspects:

-"fuel oil density indicates the ignition quality of a fuel
= The viscosity of fuel need to ease of atomization and convenience to pump the
fuel within the system.
fuel used on board ships shall have a flash point of not less than 60C.
-escape pour point and cloud point, because pour point is the lowest temperature
at which the fuel ceases to flow. Cloud point it forms wax which can lead to
blockage of the filter.
-The carbon residue of a fuel. The maximum limit of carbon residue content in fuel is
22 %.
The ash content. The maximum limit of ash content in the fuel is 0.2% m/m.
Sulphur is soluble in water. Sulphur pre-combustion causes corrosion to the pistons
and liners and contaminates the lube oil. Post combustion emits SOx to atmosphere
in exhaust gases. Therefore modern ships use fuel with maximum 0.1% sulphur
content.

5. What are the treatment methods of marine heavy fuel oil used
onboard ships?
One of the most widely the treatment methodis separation. Fuels
supplied to a ship must be separated on board before use in
order to remove solid as well as liquid contaminants. Effective
cleaning of fuel and oil can be ensured by gravity and drained off
at the bottom of the tank, centrifuging and filtering.
Cleaning by centrifuging, using a clarifier to separate oil and particles and/ or a
purifier to separate two liquids: oil and water.
Purification process is used to separate water from the fuel.
The fine filters are placed directly after the centrifuge, or in the supply line to the
engine.
Also need separate the maximum quantity of water from fuel by draining the
settling and service tanks and using purifiers.

6. What is a clarifier/ purifier?

Сlarifier consist of oil inlet, clarified oil outlet and sludge scape. And purifier: impure
oil inlet, clean oil outlet, water outlet, gravity disc, sludge scape, interface line
If we speak about specific construction. Purifier consist of
Lower disc has holes
Separates water and solid substances
• Two outlets on the top: water outlet and pure oil outlet
• Gravity disc is on top of disc stack
• Sealing water is required for starting
Top disk with neck

And clarifier consist of

Lower disc has no holes
Separates only solid particles
One outlet on the top: cleaned oil outlet
No gravity disc
• Sealing water is not required
Top disk without neck
If we're talking about defining so ‘The purifier is used to separate two liquids with
different densities, such as oil and water.

And ‘The clarifier consists of a sealing ring to prevent the fuel tank from water and
solved impurities.

Operational process inside purifier: it is used for separating lubricating oil. As marine
fuel oil normally contains a small quantity of water, itis necessary to prime the bowl
each time that itis run, otherwise all the oil will pass over the water outlet
side to waste. A second outlet pipe is used for discharging water. Within the water
outlet there is 2 gravity disc, which control the radial position of the fuel oil
interface. Various diameter rings are available for each machine when different
densities of oil are used.

And clarifier: Cleaning oil which contains little or no water is achieved in a clarifier
bowl where the impurities and water collect at the bowl periphery. A clarifier bowl
has only one outlet. No gravity disc is necessary since no interface is formed; the
bowl therefore operates at maximum separating efficiency since the oil is
subjected to the maximum centrifugal force. Doesn't need to be filled with sealing
water at all.

7. Why is it needed to heat the fuel?

So we need to heat fuel? ‘The heavy fuel oil (HFO) delivered to

the ship is stored in the bunker tank where it is heated by
supplying steam to the coils installed in the tanks. Heating is an
essential process, which makes it an integral part of fuel oil
treatment. The average temperature maintained for HFO bunker
tanks is around 40°C,
‘After transferring it to a settling tank, the fuel is further heated
to ensure it is at an appropriate temperature to enter the
separators. Once the fuel is transferred to the service tank from
the separator, the oil temperature is about 80°C. The main
intention is to ensure the smooth pumpability of the fuel oil at
different processes and to separate the maximum quantity of
water from fuel by draining the settling and service tanks and
using purifiers.
Pre-heating of the oil reduces the viscosity. Lower viscosity leads to high separation
efficiency from the purifier

8. Why is lubrication important? What parts should be

lubricated?
‘The purpose of lubrication is the maintenance of a film of lubricant between any
two surfaces having relative motion.
‘The main task of lubrication is to reduce friction between the moving parts of the
engine.
In this way we ensure better performance of the engine and reduction of wear due
to friction. Lubrication also acts as a cooling means of the metal surfaces because it
absorbs a considerable amount of heat released from friction.
‘Moreover, it protects the surfaces from corrosion, even when the engine is out of
running, thanks to the good tenacity lubricants have on metals.

We can Lube two general types of surfaces — those inside the cylinders and those in
the bearings.
9. What is “bunkering”? Name safety requirements to bunkering
procedure.
In shipping, the term bunkering describes the process of
supplying the fuel which is used to power a vessel's engines and
run on-board machinery

All bunkering operations should be carefully planned and executed in accordance

with MARPOL regulations
Personnel involved in the bunkering operation on board should have no other tasks
and should remain at their workstations during topping-off. This is particularly
important when bunkers are being loaded concurrent with cargo operations, in
order to avoid conflicts of interest for operational personnel.

All ships are subject to surveys to guarantee that the structure, equipment,
materials and arrangements thoroughly comply with the Convention which
regulates the conditions when and where oil discharges from tankers are allowed.

strictly forbidden to discharge in special areas including the Black Sea, the Baltic Sea,
the Mediterranean Sea and the Persian Gulf,
MARPOL provides an oil record book requirement, where the movement of cargo oil
and its residues has to be recorded, These book entries can be freely inspected by
any member states at any time.

Check all bunker tanks to ensure that the fuel is only being received into the correct
tanks, make regular inspections of the manifold and hose. The operation must halt if
any small drips are seen and the leak be rectified immediately;
make regular inspections of the bunker tank sounding pipes and relevant vents.
Remember to close and cap sounding pipes at all times, when not in use.
10. Why is it necessary to cool the engine?

The main function of diesel engine cooling system is to disposal

of heat which is transferred from the burning fuel to the metal
adjacent to the combustion chamber. The cooling system is also
used for cooling the scavenging air, the lube cil and all the vital
parts of the main engine.

The three main types of cooling systems are: enclosed fresh wa

em ¢ |, Sea water system and lube oil system.
At present there are two types of cooling systems installed on
modem vessels: low temperature (LT) and high temperature (HT)
cooling systems. The pistons are usually cooled by fresh water or
oil, in which case the piston system is separated from the jacket
system. The oil or fresh water leaving the pistons passes through
the coolers and into a large tank, to be recirculated