A centrifuge is used to give more effective separation of water and dirt from fuel. How does it achieve this better separation?
By increasing the separating force by centrifugal action.
By having a self-cleaning facility.
By having a high flow rate.
By using gravity discs.
A fuel oil tank is fitted with a sounding pipe, which is used from within the engine room. Which one of the following fittings given must be fitted?
Self closing cock with test cock.
Non return float valve.
Tank high level alarm.
A purifier is used to clean the fuel prior to delivering it to the service tank for use in the engine. Which one of the options shows what should be removed from the fuel by the purifier?
Water and dirt.
Back flushing filters are sometimes fitted in the onboard fuel oil treatment system. Which one of the following options best describes what the unit is normally back flushed with?
Centrifuges are often used in pairs to give a combined cleaning effect on fuel oil. Which of the options given is the preferred arrangement for these combinations?
Purifier and clarifier in parallel.
Two clarifiers in series.
Two purifiers in parallel.
Purifier and clarifier in series.
Chemical additives and stabilizers are sometimes used as part of the fuel oil treatment. Which one of the following best describes how fuel stabilizers are intended to work?
Preventing the fuel from aging.
Forming stable emulsions.
Changing the fuel molecules.
By introducing chemicals, which ignite more easily.
Edge filters are used for removal of very small particles. Which one of the following best describes where you would be likely to find edge filters fitted in the fuel oil system?
Before fuel injection equipment.
At the fuel tank outlet connection.
At purifier inlet connections.
Before the viscosity controller.
Filters are often fitted as part of the fuel oil cleaning arrangement. Which one of the following best describes why duplex (double) filter units are normally fitted?
To allow cleaning without interrupting the fuel supply.
To double the cleaning effect.
To allow automatic cleaning of the elements.
To have filters with different gauge mesh in operation at the same time.
From the options given, select all of those, which are normally fitted to a heavy fuel oil storage tank:
Manhole access door.
Fuel oil treatment systems sometimes include ultrasonic devices. Which one of the following best describes how these devices improve the condition of the fuel?
They generate high energy vibrations, which break down contaminant particles and heavy molecules.
They generate electrical pulses, which break down contaminant particles and heavy molecules.
They generate magnetic fields, which break down contaminant particles and heavy molecules.
They grind down contaminant particles and heavy molecules.
Fuel tank vent pipes positioned on the open deck are normally fitted with an automatic valve. What is the purpose of this valve?
To prevent water entering the tank during rough weather.
To prevent fuel oil spilling from the vent pipe.
To prevent air from entering the tank.
To allow vapors to escape from the tank.
High density fuels cannot be treated with a conventional purifier to remove water. Which one of the given options is the reason for this?
Insufficient density difference between water and fuel.
Insufficient heating facility.
Insufficient flow rates.
Emulsification of fuel and water.
Incompatibility is the term used to describe which one of the fuel oil storage problems given in the answer options?
Settling out of dirt from contaminated fuel oil.
Occurrence of microbial contamination of a fuel.
Separation of the heavy and distillate components of a fuel.
Sludge formation following mixing of two normally stable fuels.
MARPOL Annex I deals with the prevention of which of the following forms of marine pollution from ships?
Pollution by noxious liquid substances in bulk.
Pollution by sewage.
Pollution by garbage.
Pollution by oil.
MARPOL Annex I requires new ships with a total bunker capacity greater, than a certain limit to have fuel oil tanks positioned so that no part of the tank is formed by the outer hull plating. What is the limit?
5 000 m3.
2 500 m3.
MARPOL Annex VI deals with the prevention of which one of the following forms of pollution from ships?
Marine pollution by oil.
Air pollution due to exhaust emissions.
Environmental pollution by garbage.
Environmental pollution by harmful substances carried in packaged form.
MARPOL allows fuel oil to be stored within the fore peak and after peak tanks. True or false?
Mechanical homogenisers are sometimes fitted as part of the fuel oil treatment arrangement. Which one of the following options given best describes the effect of a homogeniser on fuel oil?
Increases the density.
Reduces the density.
Separate solids and water from the fuel.
Grinds solid particles down in size.
Safe operation and pollution prevention procedures should be contained in the ships Safety Management Manual as part of the company’s Safety Management System. Which legislation requires this?
Some centrifuges used for oil have a solenoid valve in the water outlet, which is controlled by a water sensor in the oil outlet. What is this type of centrifuge used for?
Treating high density residual fuel oils.
Treating lubricating oil.
Treating distillate fuel oil.
Treating fuels with minimum water content.
Stabilizers are sometimes used as part of the fuel treatment to improve performance. Which of the given options best describes the action of fuel stabilizers?
They reduce the oxidation rate in storage.
They kill off any microbes in the fuel.
They help to separate out any water from the fuel.
They break up heavy hydrocarbons.
Suction strainers are fitted to most fuel oil treatment systems. Which one of the following best describes the main purpose of a suction strainer?
To protect the pumps from large solid particles.
To protect the pumps from any water in the fuel.
To remove all of the solids in the fuel.
To improve the flow rate to the centrifuges.
The International Maritime Organization’s pollution legislation, MARPOL, contains six annexes dealing with different aspects of marine pollution. Which of the options is the MARPOL annex, which deals with air pollution by ships?
The International Maritime Organization’s pollution legislation, MARPOL, contains six annexes dealing with different aspects of marine pollution. Which of the options is the annex dealing with oil pollution by ships?
The International Safety Management Code, the ISM Code, as it is commonly referred to, deals with which of the given options?
The safe operations of ships and the prevention of pollution by ships.
Only the safe operation of ships.
Only the prevention of pollution by ships.
Only environmental safety.
The main purpose of purging cargo tanks with Inert Gas (IG) is to prevent explosive atmosphere in the tanks. What are the standard requirements for oxygen content in the IG supply line and in the cargo tanks?
Maximum 5 % and 8 % respectively.
Maximum 6 % and 11 % respectively.
Maximum 0 % and 5 % respectively.
Maximum 2 % and 5 % respectively.
The number of fuel oil tanks in a ship is decided upon by considering a number of factors. Which one of the options is one of the most important factors, which would be taken into consideration?
Cargo carrying capacity.
Segregation of fuel types.
Tank vent positions.
Fuel transfer pump capabilities.
The purpose of the fuel settling tank is to allow water and dirt in the fuel to separate so it can be drained off. Which of the following factors is the main reason for the separation occurring?
Difference in viscosity between the fuel and the water and dirt.
Difference in density between the fuel and the water and dirt.
Difference in temperature between the fuel and the water and dirt.
Difference in volume between the fuel and the water and dirt.
When a centrifuge is setup as a fuel oil clarifier it normally only separates solids from the dirty fuel. How is the setup of a clarifier different to that for a purifier?
The water outlet is closed off by a solenoid valve.
The water outlet is closed off by the top cover of the disc stack.
The disc stack has no distribution holes.
The gravity discs with the largest diameter holes are fitted.
When centrifuges are setup as fuel oil purifiers they often have gravity discs or gravity plugs fitted. How does fitting different densities to be treated?
They control the position of the interface.
They alter the height of the disc stack.
They alter the position of the oil outlet.
They alter the flow rate through the purifier.
When used in relation to fuel oil, the term instability refers to which one of the following situations?
Possibility, that fuel components will separate during storage.
Possibility, that the fuel will burn unevenly during combustion.
Possibility that the fuel will require additional heating for transfer.
The fuel is a blend of two or more grades.
Which of the following options best completes the following statement? The main reason for heating fuel oil before it enters a purifier is to:
Increase the density difference between fuel and water.
Increase the viscosity difference between fuel and water.
Decrease the density difference between fuel and water.
Decrease the viscosity difference between fuel and water.
Which of the following options best describes the term “incompatible” when applied to fuel oil?
The fuel becomes unstable and forms sludge when mixed with another fuel.
The components of a fuel separate out over time.
The fuel is not suitable for the machinery onboard.
The fuel does not match the ISO 8217 specification.
Which of the following options describes a feature required, where sight glasses are used to show fuel oil tank contents?
Self closing cocks or valves.
Seamless tubular glass.
Which of the following options gives the maximum temperature allowed for the heating medium in a fuel oil tank?
Which of the following options would you describe as being a double bottom tank?
A tank, formed between the hull bottom plating and the inner floor plating.
A tank with a void space in the bottom.
A tank where the hull plating is double thickness.
A tank, which can be used for two different purposes.
Which one of the fittings listed would you expect to find on a fuel oil tank air vent positioned on an open weather deck?
Vent head with float shut off valve or similar.
Self closing cock.
Remote closing valve.
Which one of the following best describes how water is removed from fuel oil when static filter modules are used instead of centrifuges?
They contain edge filter elements.
They contain fine mesh elements.
They contain paper elements.
They contain coalesce elements.
Which one of the following describes the normal way of removing accumulated water from a fuel oil settling tank?
With a centrifuge.
With a water pump.
During manual cleaning.
Regular draining using the drain cock.
Which one of the following options best describes the conditions under which microbial contamination of distillate fuel is most likely to occur?
The fuel contains sulphur.
Oxygen is not present in the fuel.
Oxygen is present in the fuel.
Water is present in the fuel.
Which one of the following options describes the aim of legislative changes that require many ships to have fuel oil tanks sited away from the ship’s side and bottom?
Increase the amount of fuel, that can be carried.
Reduce the amount of cargo, that can be carried.
Increase the ballast capacity of ships.
Reduce pollution in the event of collision or grounding.
Which one of the following options describes, when remote closing valves are required to be fitted in fuel oil tank outlet lines?
When the fuel oil tank is in the same space as the machinery it supplies.
Required for all fuel oil tanks.
Only required for fuel oil settling tanks.
Only required for fuel oil service tanks.
Which one of the following options is a fitting, that will always be found on fuel oil service and settling tanks?
Self closing drain valve or cock.
Remote reading contents gauge.
High and low level alarms.
Which one of the following options must be fitted on an air vent for a fuel oil tank?
Self closing cock.
Which one of the following would be the normal way to remove microbial contamination from fuel oil?
Treatment with biocides.
Treatment with fuel stabilizers.
Treatment with combustion improvers.
Regular draining of tanks.
* In some questions there may be more than one right answer.