Fuel Systems

Question 1

What are the 5 ways of embarking fuel?

Answer 1

RAS
Road bowser/tanker
Jetty storage tanks
Lighter barge
Fixed jetty pipeline

Question 2

What is the purpose of the filling trunk and manifold?

Answer 2

To even out the pressure of the fuel when embarking.

Question 3

What is a displacement tank?

Answer 3

A fuel tank that will contain sea water. It holds fuel for storage and acts as a ballast for ships stability.

Question 4

To what level can displacement tanks be filled while at sea and why?

Answer 4

90% capacity to reduce the risk of fuel being discharged into the sea and allow for expansion due to temperate change.

Question 5

Why are displacement tanks divided up?

Answer 5

To avoid splash due to the movement of the ship.

Question 6

What is an un-dispaced tank?

Answer 6

Tank that does not contain sea water and only holds fuel (could be dirty fuel).

Question 7

What is the purpose of the centrifuge?

Answer 7

It separates fuel from water using centrifugal force. One clean, the fuel is then stored in a service tank ready for use.

Question 8

To what level should un-displaced tanks be filled?

Answer 8

95%

Question 9

What is the purpose of the transfer pump?

Answer 9

It transfers fuel from the un-displaced tanks to the machinery space service tanks.

Question 10

What is a coalescer?

Answer 10

Water separator for any final water droplets that may still be in the fuel.

Question 11

How does fuel get from the displacement tanks to the un-displaced tanks?

Answer 11

Via the centrifuge, it cleans the fuel and acts as a pump.

Question 12

What is the purpose of the fuel tank filling valves?

Answer 12

To isolate the manifold from the displacement tanks.

Question 13

What level do the pre filters filter the fuel to?

Answer 13

5 microns

Question 14

What is the ring main?

Answer 14

A machinery space fuel supply system delivering fuel to individual ready use tanks and main gas turbines.

Question 15

What is MBG and where would it generally be found?

Answer 15

Micro biological growth. Found in virtually all fuels, especially when there is water in the tank. Most likely to be found in the interface.

Question 16

What is the purpose of the salt water gravity tank?

Answer 16

To supply the displacement tanks with sea water as fuel is removed. The gravity tank is higher than the displacement tanks, giving a head of pressure.

Question 17

What does the emergency run down valve do?

Answer 17

Allows a gravity fuel supply to gas turbines should the boost pressure be lost.

Question 18

What 4 tests are carried out on diesel?

Answer 18

Visual test
Water reaction test
Colour test
Diesel fuel filtration test kit

Question 19

What level does a coalescer filter fuel to?

Answer 19

10 ppm

Question 20

Explain visual test.

Answer 20

Fuel should appear clear and bright at all times.

Question 21

Explain water reaction test.

Answer 21

Carried out at embarkation. 20ml distilled water and 80ml fuel left to settle. Must be no more than a 2ml interface (cloudy area).

Question 22

Explain colour test.

Answer 22

Gives an indication of fuel age. Darker is older. Lovibond colour comparitor test.

Question 23

Explain diesel filtration test kit.

Answer 23

Gives an indication of how quickly filters will block. 250ml of fuel must pass before pressure reaches 15PSi

Question 24

What 3 things are fuel tested for?

Answer 24

Water
Dirt
Surfactants

Question 25

What are surfactants?

Answer 25

Detergents/degreasers

Question 26

Why do we test fuel?

Answer 26

Ensure it is of good quality
Ensure all salt water is removed as sodium will cause corrosion
Ensure all water is removed as it can cause MBG
Dirt in fuel will cause filters to block

Question 27

Name 4 hazards associated with fuel systems.

Answer 27

Fire and explosion
Toxicity
Dermatitis
Pollution

Question 28

What is the path of fuel from tanker to engines?

Answer 28

Tanker
Filling trunk 
Manifold
Displacement tanks
Centrifuge 
Un-diplaced tanks
Fuel transfer pump
Service tank
Fuel boost pump
Fuel boost ringmain
Engine