DieselShip's Online Content Library

Q1.a) What are the different types of coupling bolts used in practice? Name at least 3. (3)

b) Explain with the help of sketch, as to how a ‘pilgrim’ hydraulic bolt is fitted and removed? (8)

c) How are fitted boards installed on the coupling? (5)

Q2. (a) Explain the working principle of a fuel oil purifier. (8)

(b) Explain briefly the significance of the friction clutch mechanism. (4)

(c) List the alarms and trips associated with a purifier. (4)

Q3. Which of the materials listed is used as the dynamic seal material on mechanical seals installed on most centrifugal pumps used in water service? (16)

(a) Copper.

(b) Copper and carbon.

(c) Carbon.

(d) Bronze.

Briefly justify your answer.

Q4. (a) Sketch and describe a central cooling freshwater system for a motor ship. (8)

(b) State the possible causes of corrosion in the closed system described in (a). (4)

(c) Explain how protections against corrosion is provided? (4)

Q5. (a) State why the presence of oil in boiler water is considered serious. (4)

(b) Suggest likely sources of oil contamination. (4)

(c) Describe how the source is traced. (4)

(d) Describe how the whole steam plant is restored to oil free conditions. (4)

Q6. Describe the following metallurgical tests and explain why EACH is carried out:

(a) Impact test (4)

(b) Hardness test (4)

(c) Endurance test (4)

(d) Tensile test (4)

Q7. If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be (16) (a) Contaminated fluid

(b) Pitted thrust rings

(c) Worn pintle bearings

(d) Obstructed suctions passage

Briefly justify your answer.

Q8. Write short notes on the following:

(a) Incinerators (5)

(b) Airline relief valve (5)

(c) Mixing column (6)

Q9. (a) Make a detailed sketch of a direct expansion two room refrigeration system. (10)

(b) Give a full description of such a Refrigeration System, explaining the purpose of the relevant control and safety devices. (6)