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1
Question
Which metal is primarily used for galvanizing steel to prevent corrosion?
Answer
Zinc
2
Question
What does a sacrificial anode do in corrosion protection?
Answer
Corrodes preferentially to protect metal
3
Question
What is brass composed of?
Answer
Copper (66%) and zinc (34%)
4
Question
Describe a key application of aluminum in maritime industries.
Answer
Shipbuilding, docks, and boat hulls
5
Question
Name two highly resistant marine plastics.
Answer
Polyethylene and polycarbonate
6
Question
What is corrosion and how does it affect metals?
Answer
Chemical/ electrochemical deterioration into oxides
7
Question
What are the two principal methods to prevent corrosion?
Answer
Cathodic protection and coatings
8
Question
How does cathodic protection work?
Answer
Suppresses electrochemical reactions, often by using sacrificial anodes
9
Question
What is the role of a sacrificial anode in seawater?
Answer
Corrodes preferentially to protect other metal surfaces
10
Question
What is the purpose of impressed current systems in vessel hulls?
Answer
To make the hull cathodic and prevent corrosion
11
Question
What are essential steps for maximum coating adhesion on steel?
Answer
Clean, dry, and free of contaminants
12
Question
How does film thickness impact corrosion protection?
Answer
Thicker films delay oxygen and water permeation
13
Question
Why should coatings have good undercut resistance?
Answer
To prevent corrosion creep at damaged areas
14
Question
Name an anticorrosive pigment used in coatings.
Answer
Zinc phosphate
15
Question
What is a key advantage of non-ferrous metals?
Answer
Malleability (shapeability)
16
Question
What is bronze mainly composed of?
Answer
Copper (90%) and tin (10%)
17
Question
Define flash point and its significance.
Answer
Temperature at which vapor ignites; Diesel has a higher flash point than gasoline
18
Question
What is spontaneous combustion?
Answer
Fire caused by self-heating of materials without external ignition
19
Question
Why are heat shields on engine exhaust manifolds used?
Answer
To protect personnel and prevent ignition of flammable leaks
20
Question
Where should paint and chemicals be stored onboard?
Answer
In dedicated non-combustible lockers away from living and engine areas
21
Question
Where are fuel tank vents normally terminated?
Answer
On the weather deck with fire screens and shutoff valves
22
Question
What is the function of a fire door?
Answer
Resist fire and smoke to compartmentalize and delay spread
23
Question
How do water-tight doors differ from weathertight doors?
Answer
Water-tight doors prevent water ingress; weathertight prevent outside water ingress above waterline
24
Question
How does an oil-water separator operate to treat ballast water?
Answer
Separates oil and solids based on gravity; <5ppm oil discharge
25
Question
What does a self-priming pump do?
Answer
Automatically removes air to start pumping, maintaining prime
26
Question
What is the primary function of self-priming pumps?
Answer
To have liquid inside the pump for startup, enhancing efficiency.
27
Question
What is cavitation, and why is it harmful?
Answer
Rapid vapor bubble collapse causing damage due to high-velocity liquid blasts.
28
Question
How do centrifugal pumps move fluid?
Answer
Using rotational energy transferred from impellers via centrifugal force.
29
Question
Why is air considered the primary enemy of centrifugal pumps?
Answer
It causes air binding, preventing pump operation.
30
Question
Describe the working principle of a reciprocating positive displacement pump.
Answer
A cavity's volume changes to intake and discharge fluid through pistons or plungers.