Question asked to student who appeared in mmd exam previous year

 MMD Noida 18.09.2017

CoC Attempt

Only Meena sir

Electrical

#Battery charging circuit, what is trickle charge and its ameperage

#MSB safeties

#how to find earth fault

#how to increase insulation of induction motor

#explain AVR, why voltage dip?

#explain SCR full, where is it used

#explain working of ICCP

MEP

#type of engine? 11K98ME-C

what is 'K' in above how is it classified?

#how to remove a stuck stud

#bunker oil leaking into cofferdam. how to fix immediately.. ans is to transfer bunker below the

crack in bulkhead

#fuel injector overhaul... testing, how to know it is leaking, how to fix leak (lapping of needle

valve not allowed..only replace)

#reasons why DG not starting... he wants all reasons

some more in mep I don't remember.

vizag , 18th sep

2nd attempt ( COC )

fn#3

- sheer strake and its purpose , where to where it extends.

- life boat regulations and its equipment.

- co2 room regulations.

- flare and its purpose at least 4 .

- marpol annex 1 discharge criteria.

- free surface effect and its effect in ship.

- IGG full

- Safties on tanker

Fn#6

- AE decarb and all clearances.

- centrifugal pump overhaul , checks and clearances.

- compressor overhaul , major parts to be overhauled for increasing efficiency and checks during

running .

- properties of LO comp.

- bilge pump not taking suction , reasons . how to find leak in bilge pump line.

- fuel injector testing and overhaul.

AND THEN INTERNAL ASKED HOW WAS UR ORAL .

IT WAS GOOD SIR.

GO YOU ARE PASS.

18/9/17 Mmd mumbai

Safety

sart regulations

Co2 fixed fire fighting system n periodic maintainance in detail

Lifeboat regulations n launching proced

On load offload release

Centrifugal brake n x questions

Solas ch 9 regulations n certuficates

Ch 11.1 n 11.2 in detail with lots of x questions

Solas regulations for electrical safeties onboard

Categories of noxious liquid substances n explain each

Discharge criteria for each substance above

Name classes under imdg code...he wants all 9 classes in order

Draw discharge connection for sewage

Define camber sheer block coefficent wake margin plate

Explain inclining exp

Angle of lol n x quest

Fse

Draw bulbus bow n advantages/disadvantages

Collision bulkhd

Draw ur ships transverse section

Anti heeling system expl

Electrical

Difference b/w lap n wave winding

Transformer constuction

Differnce b/w earthed n isolated neutral

Wat is resonance in ac ckt

Soft starter expn wrkg

Single phasing

Types of exitation in generator

Diff b/w dc n induction motor

Megger wrkg with diag

Static elect n x ques

How to parallel generator

Wat is t effect of kvar loading on motor

How tyristor wrk

Prefrenctial tripping

Reasons for loss of exitation

How to overcome ac/dc surge

Salinometer expln

Motor

Gear p/p charactistic curve

Npsh draw n lots of x quest

Wat is propelar n hull effiecy

Volumetric efficy

Crosshead lubrication draw

Cal power of m/e

Types of propellars

Crankpin lubrication

Tappet clearence

Draw holding down bolt arrangement

Diff b/w ball n roller brg

Wat is the use of stay plates

Why negative cam in starting system

Liner lubtication in 2 n 4 stroke

Draw rotary vane gear mechanism n x ques on steering system

Mep

Con rod bent how to find n renewal procedure

Purifier overhaul

M/e liner renewal procedure...he wants every step in order

Draw piston cooling system on ur ship

Bottom end brg renewal of 4s

Boiler water test

Refer short cycling reasons ...he wants atleast 7pts

Draw pintle brg clearence n how to chk n value

Rudder drop

Draw flairing tool n how it wrk

Reciprocating p/p ovehal

Gate v/v overal

Types of reamers...

N many more x questions cant remember

[20/09, 15:59] ‪+91 97964 66685‬: NOIDA MMD MEENA ONLY

first attmpt

20/09/17

Motor &Mep

1.ME SPEC...CROSS QUSTN

2.VIT SUPER VIT

3.FUEL PUMP ME

4.START AIR SYSTM

5.START AIR INTERLOCKS

6.BEARING CLEARANCES

7.FUEL INJECTOR TESTING

8.LIQ CHARGING REF SYSTM

9.BOILER WATER TESTING

10.BLOWDOWN

11.GAUGE GLASS BLOWDOWN

12.BOILER SURVEY

13.ACCUMULATION PR TEST BOILER

14.EXHST TEMP HIGH IN ONE UNIT REASONS

15.REVERSING

16.SERVOMOTOR FUNCTIONING

Electrical

1.MSB MAINTENACE

2.WORKING OF IND MOTOR

3.440 V TO 24V

4.STARTERS

5.FUSES ND ORDERING

6.INGRES PROTECTION

7.BRUSHLESS EXCITATION

8.COMPOUND EXCITATION

9.PARALLING

10.WORKING OF CONTACTOR

Diagrams aate hai to sb sahi rhega nd be confident chaahe galat bolo... Zyada galat b na bolna

RESULT:MOTOR MEP ND ELECT

MEO CLASS 4 ORAL QUESTION BANK *FUNCTION 3: COSCPOOL*

 1. Fire main line fittings

2. Purifier room fire

3. Paint locker fire

4. CO2 flooding procedure

5. Uptake fires

6. O2 and C2H2 storage and operation safety

7. EPIRB and SART

8. SOPEP

9. LB brake/ lowering procedure

10. 103.Deck foam system?

11. 104.Where isolation valves given in fire main?

12. What is hydrogen fire?

13. What are the indications of EGB fire?

14. 2.DCP fire extinguisher?

15. Routine checks on FFA

16. Flammability diagram

17. In your kitchen what fuel is used

18. Why is the flame not traveling to the cylinder

19. LEL, UEL

20. Flammability range?

21. Between a log and a small stick which burns faster

22. When you blow on a matchstick the fire goes out. In a stove/or a black smith's hearth

blowing air increases the fire.Why?

23. Why is a Relief Valve fitted on fire main?

24. International shore connection; Size? Where fitted? Which part is standard?

25. Enclosed entry procedure

26. ELSA, EEBD

27. 33 Fire main line isolating valves

28. How does a flame screen work? What is the difference between a flame screen and a flame

arrestor?

29. What is a flashback arrestor?

30. Why should Acetylene bottles be used in the upright position?

31. What is the correct position for using a portable foam extinguisher?

32. Why is a sand box provided on the boiler flat?

33. What are gas-free conditions for man entry?

34. Should the ventilation blower be running in supply mode or exhaust mode, when the Oxygen

check is made?

35. In a tanker, why are bonding straps used on cargo pipelines?

36. What is the rating of the electrical hand glove?

37. What is the important first aid for an electrical shock victim?

38. Is there any protection for a CO2 cylinder in case of a fire in the CO2 room itself?

39. Is the CO2 in the bottle in liquid condition or gas?

40. How does the CO2 alarm ring when the panel door is opened?

41. Can engine room bilges be pumped out in special areas?

42. What will be your action when you discover smoke coming out of

43. During your watch, if you get a under piston temperature high alarm, what will you do?

44. During your night duty on a UMS vessel, there is a fire alarm from E/R. What will be your

action in case of

Top

a. Purifier room fire

b. Running generator exh manifold on fire

c. Boiler front on fire

d. Bilges on fire

45. 102.CO2 and DCP difference?

46. Man overboard drill

47. Oil spill drill

48. Life raft floatation

49. Ship's Whistle? How does it work? Where is it fitted?

50. L boat tricing pendant / Bowsing in tackles; Purpose.

51. What is HRU? How does it work? Where is if fitted?

52. What is a Life buoy? Where is it fitted?

53. What is flash point, firepoint and auto ignition temp.

54. What are the tests done before enclosed space entry?

55. What spaces are defined as such?

56. What is the acceptable HC level for man entry?

57. What is TLV? How many types are there?

MEO CLASS 4 ORAL QUESTION BANK *FUNCTION 5 : EECEOL*

 1. What is KVA?

2. What is special about Steering gear Overload safety?

3. Explain the condition for Paralleling of Alternators?

4. What does different position of the synchroscope needle mean; what is the difference

between 6 o clock and 12 clock?

5. Why do we close the switch at 11 o'clock and not at 12 o' clock?

6. Why is a Megger used for insulation test and not a multi meter?

7. What are the safeties on MSB?

8. When does Reverse power flow?

9. What is the harm if reverse power flows?

10. How is the protection against reverse power given?

11. How do you test reverse power trip?

12. What is the full form of ACB?

13. If you press the ACB Close button on an idle generator what will happen?

14. What is Under-voltage protection?

15. What is the meaning of preferential trip? Why is it provided?

16. What is the purpose of the earth fault indication on the switch board?

17. If you get an earth fault alarm what will you do?

18. What is Direct Current?

19. What is alternating current?

20. What is meant by phase in AC?

21. Is there phase in DC?

22. Why is DC not much in use now?

23. Where are you likely to see it used?

24. What does three-phase current mean?

25. What is rms value?

26. What is the meaning of power factor?

27. What is the usual value you see onboard?

28. What is the best value possible?

29. What is the benefit of improving power factor?

30. How can it be improved?

31. What is the meaning of saying I and V are in phase?

32. What is the difference between KW, KVA and KVAR?

33. Why are motor ratings given in KW and that of alternator and transformer given in KVA?

34. Where does reactive power go?

35. What is a semi conductor?

36. What is doping?

37. What happens to insulation when temperature rises?

38. What happens to resistance of conductors when temperature rises

39. What is an induction motor?

40. What is "slip"?

41. What is a synchronous motor?

42. Where is it used?

43. How do you use a multimeter?

44. What is an AVO meter?

45. How do you check continuity?

46. What limits the electrical load?

47. What is the voltage used in a meggar?

48. How does current flow during welding?

49. What do we use for welding on ships? AC or DC?

50. What is the voltage?

51. What is the voltage used for ignition in boilers/incinerators etc.?

52. Why is it different from that for welding?

53. Does current flow through hull during welding?

54. If so why don't you get a shock?

55. What is safe voltage to prevent shock?

56. What is the meaning of earthing in a ship?

57. What is the meaning of Star winding/ Delta winding?

58. Is the ship's alternator Star wound or Delta wound?

59. What is the meaning of ACB, MCCB, NFB?

60. What is a magnetic contactor? Where is it used?

61. What is a relay? How is it different from a magnetic contactor?

62. Can you draw a DOL starter circuit?

63. What is the meaning of overload?

64. What is meaning of short circuit?

65. How is protection provided for OL and SC?

66. What is the function of a fuse?

67. What is the normal setting of overload relays?

68. How does a thermal overload relay work?

69. What is single phasing?

70. How can it happen?

71. What is the harm caused by this?

72. What protection is provided against this?

73. Why is it necessary that incoming alternator frequency is more than bus bar?

74. What is dark lamp and bright lamp method for synchronizing? How is the connection made?

75. Apart from renewing bearings is there any reason for opening up motors for maintenance?

76. Why is reverse power protection required?

77. Why is this reverse power used instead of reverse current in alternators?

78. What is the meaning of excitation in an alternator?

79. Is the field current in an alternator AC or DC ?

80. Is the field rotating or stationary?

81. How is it supplied?

82. What is a brush less alternator?

83. How is the excitation achieved in this?

84. What is the meaning of residual magnetism?

85. Why is an air compressor started unloaded?

86. How is the speed of a 3-phase induction motor varied?

87. How is the direction of rotation varied?

88. How does this cause a rotation to change?

89. How is the speed of a DC motor varied?

90. How is the direction varied?

91. What is a diode?

92. What is a zener diode?

93. What is a thyristor? What is an SCR?

94. How does an inverter work?

95. How does a tube light work?

96. What is the function of the starter in a tube light?

97. What is the function of the choke?

98. Where is a slip ring used and where is a commutator used?

99. What is capacitance?

100. Does current flow though a capacitor?

101. What is the unit for capacitance ?

102. What is a neutral?

103. What is the difference between neutral and earth?

104. What is a synchronous condenser?

105. Where and why is it used?

106. If a motor is wound star and you want to change to delta what should you do?

100 If the AVR, is defective, when additional loads come on will the generator be able to take it?

How do you test, reverse power trip, high current trip, preferential trip?

102. What is residual magnetism? Where is it important?

103. Sometimes, when you change the running direction of a E/R blower (from supply to

exhaust) it trips. Why?

104. What is the function of the friction clutch mechanism used in purifiers?

105. What is the regular maintenance done on batteries?

106. What safety precautions need to be taken during maintenance on batteries?

107. Why is special lighting used in battery rooms?

108. What is the voltage available from each cell in a lead acid battery?

109. What is the full battery voltage ?

110. How is this voltage achieved?

111. What is the meaning of a normally open contact?

112. How does a Salinometer function?

113. How does the air compressor start and stop automatically?

114. How is the cold room temperature maintained?

115. What is a self-monitoring alarm circuit?

116. Out at sea, if there is a black out during your watch, what action will you take?

117. After a black out the emergency generator comes on; On restoring the main supply we are

closing the circuit breaker of the main generator with out bothering about synchronizing. How is

this possible?

118. How does the emergency generator start automatically?

119. If all your air bottles are at low pressure and there is a blackout how do you start the

generators?

120. What is a shaft generator?

121. Even though the main engine runs at varying speeds, how does the alternator maintain

constant frequency?

122. Is the alternator connected star or delta

123. Why is 440 V used for motors and 110/220 V used for lighting?

MEO CLASS 4 ORAL QUESTION BANK *FUNCTION 6: MROL*

 1. Explain how will you o'haul a fuel injector

2. Explain how you will change gland packing of a pump.

3. What is a SDNR valve?

4. How do you o'haul a globe valve?

5. How does a gate valve work?

6. If a gate valve is stuck, what could be the reason?

7. How is a job centered on a chuck in a lathe

8. What safety precautions will you take if working on a lathe?

9. What is a reamer? Where is it used?

10. How does a Quick closing valve work?

11. How do you reset a QC valve after operation?

12. Is there any difference between relief valve and safety valve?

13. Explain how will you prepare for Bunkering?

14. How do you set tappet clearance?

15. What are the steps to take after a blackout at sea?

16. How do you pressure test a fuel vale?

17. How will you replace an exhaust valve seat?

18. How do you install a bearing on a shaft?

19. How do you specify pipe size?

20. What do the numbers on bearings mean?

21. What is the common size between different schedules of a pipe?

22. If an A/E does not start what will be your action?

23. Your action if T/C is surging?

24. Why is a Steam trap used in condensate return lines?

25. How is gas cutting done?

26. How many valves are there on a gas-cutting torch?

27. How do you light a gas-cutting torch and adjust the flame?

28. How do you set up a new pipe for welding?

29. What is GPR/GPO/LH electrodes?

30. How do you select the correct current setting for welding?

31. Crank pin brg clearance

32. Telescopic feeler gauge

33. Piston removal procedure

34. Welding defects?

35. Bridge gauge main brg clearance

36. How does a Stud extractor work?

37. How does a chain block work?

38. What are the safeties on cargo cranes ?

39. What are the safeties on ER crane?

40. How is the load controlled during lowering?

41. How is the E/R crane load tested?

42. Fuel valve not coming out?

43. Setting exhaust valve timing

44. Pumps o'haul?

45. Type of drill bits?

46. Types of threads?

47. Pipe schedule?

48. Important dimensions of flanges? Types of flanges?

49. Indications of scavenge fire? What action will you take?

50. Where are wear rings used? What is their purpose?

51. Boiler gauge glass? Reflex type? Blow through procedure?

52. .ISSA code book?

53. SG hunting gear?

54. Axe blade? How fitted?

55. Load test?

56. SCBA pressure testing

57. Welding surface preparation

58. No water in GG ? What action

59. Flaring tool

60. What is an ermato joint?

61. Why is a copper gasket annealed ?

62. How will you supervise a lub oil Filter cleaning?

63. What precautions have to be taken during cleaning of SW line filters?

64. What is a Dead mans alarm

65. What will be your action if your Reliever appears drunk

66. Your oiler appears drunk. What is your action?

67. Compound gauge?

68. Method of blowing through gauge glass

69. Pump shaft broken? Suggest epairs?

70. What is Gear Back lash?

71. What are different types of gears seen in ship?

72. What is hunting tooth

73. Why is gear oil different others?

74. What are the different types of Taps and Dies?

75. Why do you take Ullages? How do you calculate liquid quantity?

76. What is VRF?

77. What do you check up while opening piston?

78. Q closing valve operation? Why do you shut the valve again before opening?

79. Start airline getting hot - what action?

80. Draw a LS of ball bearing fitted on a shaft.

81. What is a lip seal? Sketch

82. Sketch a mechanical seal.

83. Exhaust bellow sketch?

84. What is a dresser coupling

85. What is Bumping Clearance? How do you measure it?

86. Why is a centrifugal pump started with its discharge valve shut?

87. How will you align a pump to its motor?

88. What checks will you make on a bottom end bearing bolt?

89. How do you measure ovality of a crank pin?

90. How does hydraulic tightening work?

91. Why is the jack turned back a little while slackening?

92. What will you check in UP space inspection?

93. How will you do crankcase inspection?

94. Shipside valve is leaking into E/R. What will you do?

MEO CLASS 4 ORAL QUESTION BANK *FUNCTION 4B: MEOL*

 1.Why is Boiler water treatment required?

2. What is the allowed chloride content?

3. Why is the boiler water circulating pump required for EGB?

4. How does a bourbon pressure gauge work?

5. How do you blow through a boiler gauge glass?

6. Why is a ball given in the gauge glass?

7. How do you tighten a gauge glass after assembly?

8. What is the setting of a boiler safety valve?

9. What is the normally allowed chloride content in a water tube boiler?

10. How do you blow down a boiler and inspect it?

11. Why is pre purging necessary before firing boilers?

12. How does flame failure alarm come?

13. Type of boiler burner on last ship

14. What is the voltage used for the ignitor?

15. How will you know EGB is leaking?

16. How will you stop the leak?

17. What is the purpose of soot blowing?

18. When do you start the circulating pump?

19. What is the temperature of steam in the boiler?

20. What is meant by superheated steam?

21. How is a boiler safety valve set?

22. What is the setting?

23. What is the meaning of accumulation of pressure test?

24. How do you blow down a boiler and inspect?

25. How do you repair leaks?

26. How do you blow through gauge glasses?

27. What is the safety mechanism in case the glass breaks?

28. Which part of a ship's boiler has a higher safety valve setting? EGB or auxiliary?

29. When is the pressure testing of boilers done? How is it done?

30. Why is Fridge compressor belt driven?

31. What is meant by 1 ton of refrigeration?

32. Is there any difference in lub oil pressure readings of fridge compressors when compared to

air compressors?

33. How do you read the lub oil pressure of fridge compressors?

34. Some times the pressure gauges used in fridge systems also have temperature readings.

What is the use of this?

35. How is the temperature of cold room maintained ?

36. What is the role of the TEV?

37. What is mean effective pressure of diesel engine?

38. What is the cooling water treatment

39. What tests are done on L.O.?

40. What is the correct procedure for L.O. sample collection?

41. Exhaust temp of one unit is high; what could be the reason?

42. How is LO for X head lubrication delivered in (B&W/ SULZER Engines)

43. Why is a bursting disc provided in air compressors?

44. Where is it provided?

45. If a bursting disk ruptures, what will be your action?

46. What are the safeties fitted on air compressors?

47. If the interstage relief valve is lifting, what could be the reason?

48. Why is multistage compression used?

49. How will you test the working of a compressor safety valve?

50. How does the Oil mist detector work?

51. How will you test the opening pressure of a crank case relief door?

52. How many tie rods will be there? Function of tie rods?

53. What is a lantern ring?

54. What is the role of the Thrust block ?

55. Where is the thrust bearing in MC series or RTA engines?

56. Why is the thrust bearing at the aft end of the engine and not at the forward end?

57. Why is the thrust bearing close to the engine and not close to the stern tube?

58. What is the allowed O2 content in IG? How is it controlled?

59. M/E stuffing box components?

60. What is the role of the stuffing box?

61. What is the difference between stuffing box drain oil and scavenge space drain oil?

62. Why are piston rings changed?

63. What is the difference between a PV breaker and PV valve? What are the settings?

64. Why is deck seal used in IG systems?

65. What are the COPT trips?

66. What is the starting procedure for COPT?

67. 4 stroke Valve timing diagram

68. What are the strokes in 2 stroke and four stroke engines

69. Difference between purifier and clarifier

70. What is the separation principle used in purifiers?

71. What is the relation between oil density and gravity disc diameter?

72. Why are telescopic pipes used for oil lubrication?

73. Why is Fuel timing important?

74. How is checked and adjusted? (engine type based on candidate's experience)

75. What is the principle of a diesel engine?

76. Why are 2 springs sometimes used in inlet and exhaust valves?

77. What will you check in springs during o'haul?

78. How does a roto cap work?

79. How is BHP calculation using indicator diagram done?

80. What is MEP and MIP?

80. What is MEP and MIP?

81. What is the difference between the two?

82. Why is cylinder head fitted in engines

83. Are there engines w/o cylhead?

84. Draw 2s timing diagram

85. Why is an expansion tk provided in jcw system?

86. Why do we Blow through' Engines?

87. How is T/C RPM measured?

88. Is there any difference between A/E and M/E Governors

89. Indicator cards why and how are they taken?

90. What is Hydrodynamic lubrication?

91. What is a rolling contact bearing?

92. What is MCR and CSR?

93. What is PS? What is its relation to kW?

94. What was the specific fuel consumption in your last ship?

95. What was the specific Cyl oil consumption?

96. What is the relation between power and rpm of a main diesel engine?

97. What will be the power developed by a main engine if it runs in DD?

98. What is the relation between the ship's speed and engine power?

99. Will the engine develop any power, if it is run when a ship is aground?

100. What is a CPP? How does it function?

101. What is the difference between fuel valve opening pressure and fuel injection pressure?

102. What is an under slung crankshaft?

103. How many crankshafts are there in Vee type engines?

104. How are connecting rods fitted?

105. Do two stroke engines need tappet clearance adjustment?

106. How will you know, without opening anything, that an engine is 2S or 4S?

107. What are the two strokes in 2S engines called?

108. Why does Sulzer use hydraulic jack bolts for main bearings?

109. What is the meaning of TBN in lub oils?

110. Why is LO of different TBN used for M/E cyl oil and Crankcase oil?

111. What are the values of TBN for A/E crankcase oil?

112. What is the difference between "heat" and "temperature" ?

113. If water is found in crank case lo, what could be the cause?

Electrical oral questions class 4 exams

 Q)What is special about steering gear safety.

Ans.)It has got overload alarm at 150% and short circuit trip.

Q)Maintenance of alternator what all to do.

Ans.) (a) Clean the felt/ air filters.

(b) Remove dust/ dirt from the rotor.

(c) Clean the connections and put some petroleum jelly.

(d) Check the air gap with the plastic feeler gauge.

(e) Check the lub oil level in bearing.

(f) Insulation resistance to take with megger.

(g) Check condition of winding.

(h) Carry out continuity test.

Q)Purpose of air gap and how checked.

Ans.)To avoid the mechanical contact between the stator & rotor and to determine the condition of the bearing. Measured with the help of feeler gauge.

Q) what are the conditions for paralleling alternators?

Ans.)  Frequency of incoimg generator should be slightly more than that of bus bar

(b) Phase angle of incoming and bus bar voltage should be same

(c) Voltage of incoming and bus bar should be same

Q)How to parallel alternators

Ans.)There are three methods of Paralleling alternators:-

(i) Dark lamp method

(ii) Bright lamp Method

(iii) Synchorscope

 

Q)Suppose a motor is not starting what checks u will make

Ans.
Electrical Checks:

1. Check the connections.
2. Check, if has tripped, then reset and try to start.
3. Check supply is coming from MSB or not.
4. Check single-phasing has not occurred.

Mechanical :

Check the coupling between the motor and driven part is not too tight.

Q)Suppose a motor is running hot what checks.

Ans.)Single-phasing, Overload is occurring, Check condition of bearing.

Q) Why insulation resistance checked and how?

Ans.)A measurement of the insulation resistance gives the best guide to the state of health of the electrical equipment.

1. Disconnect the electrical supply.
2. Refer to the electrical circuit & manufacturer’s instruction before testing.
3. Measure the insulation of the windings to the earth and as soon as possible when the machine is just hot after it has stopped. The minimum value should be 1 MW.

 

Q) Why motor insulation deteriorates?

Ans.)1.Moisture – results in decrease in the measured value of insulation resistance.

2.Dust & dirt deposits – reduces insulation resistance & failure of insulation due to oxidation.

3.Oil & Grease – prevents heat dissipation & causes dirt and dust to settle on the insulation.

4.Ageing – over the period of time the insulation deteriorates due to it getting affected by temperature variation, mechanical stresses, vibrations, moisture and some varnish tend to become hard with age & crack during the operation.

5.Temperature – Excessive temperature dehydrates and oxidizes the insulation, making it brittle & disintegrate under vibration & shock.

Q)What are portable electrical testing instruments used in ER ?

Ans.)1.Clampmeter

2.Megger

3.Multimeter

4.Tester

Q)Why preferential trip provided Purpose?

Ans.)Preferential trip is provided to safe guard the machineries which are important for safety of ship & safety of personnel onboard.

Preferential trips are designed to disconnect the non-essential services i.e., Breakers controlling Air Conditioning, Galley power, blowers, refrigeration) in the event of partial overload or partial failure of the supply, with the aim of preventing operation of the main breaker trip & loss of power to essential services.

MEO class 4 oral question on marine boiler.

 

What are the types of boiler by pressure ?

1. Low pressure boiler  –  up to 10Kg / Cm2
2. Medium pressure boiler  –   10-25 Kg /Cm2
3. High pressure boiler  –  Over 25 Kg / Cm2

What is water hammering and how will you prevent it ?

• It is the impact of moving water in steam line when the steam is allowed to enter a line with condensed water.
• The steam will condenses and partial vacuum occurred and move back the water the along the pipe with very high velocity, and the water will strike at the vent or valves.

To prevent the water hummer –

1. Install steam trap in the line
2. Open the drain first before allowing the steam into the line.
3. Crack open of steam valve at first.

How to make boiler water test on your ship ?

The boiler test is carried out as follows.

1. Firstly take the boiler water sample from the salinometer cock or test cock and cool down.
2. The test is carried out by the using maker’s supply test kit, chemicals, instruments and instructions.

How do you take boiler water sample ?

• Slowly open the salinometer cock until clean hot water coming out.
• Then collect the boiler sample with copper jar.

How to know scum blow down valve open or not ?

• It can be check by opening of ship side blow down valve. Banging noise will appear, scum blow down valve is in open position.
• It can also detect, over heating of scum blow down pipe.

Where is manhole doors fitted ?

• They are fitted at one at steam side and other one for water side.

Effect of foaming and priming ?

1. Can cause water hummer
2. Can cause contamination and scaling.
3. Can cause fluctuation of working water level.

What is boiler blow back ?

• It occurs when lighting up with explosive gas and oil droplet (Oil residue) inside the furnace without pre-purging sufficiently.
• The ignition results in a large flue gas inside the furnace and these gases blow out with increase high pressure through the furnace opening.

Procedure for hydraulic pressure test on marine boilers ?

Hydraulic pressure test is 1.25 times working pressure, ( 10 minutes maintain )

1. Close all openings.
2. Open air vent cock.
3. Fill up boiler water fully
4. Close the air vent cock
5. Place hydraulic jack to feed water line.
6. Fit standard pressure gauge.
7. Applied hydraulic pressure 1.25 times of working pressure and maintain 10minutes.

What is liquid coagulant in marine boilers ?

• It has more molecular weight, colorless solution, containing sodium aluminates, starch, terming, and resin.
• Once being dose into the boiler water floating solid particles and suspended solid are settled to the bottom of the boiler and easily remove by blowing down.

How to renew the boiler gauge glass ?

1. Shut steam and water cocks and open drain cock.
2. Check any leakage from the respective cock.
3. Slacken the gland nuts.
4. Open the cap and remove gauge glass.
5. Fit new gauge glass, correct size and length into its space.
6. Give the expansion allowance 1/8 in vertical clearance.
7. Use new packing.
8. Close the cap.
9. After fitting, warm the glass by steam.
10. Tighten the gland nut.
11. Then steam and water pressure should be tested whether they are fair and clear.
12. Close the drain and open the water and steam side cocks.
13. Check the leakage; all are satisfactory put back into operation.

Routine boiler maintenance carried out on ships ?

1. Clean the rotating cup.
2. Check and adjust the belt tension between motor and rotating shaft.
3. Clear the pilot burner nozzle and fitter.
4. Clean carbon deposit on electrodes ( igniter ) and adjust the gap.
5. Check the fuel valve and air register linkages and joints.
6. Check and clean the flame eye cover glass.
7. Check and clean inspection peep hole glass cover.
8. Clean fuel oil fitter.
9. Check the fuel oil pressure.

When boiler safety valve setting made ?

• Every boiler survey.
• After safety valve overhaul.

Why ship side blow down valve is open first and close last ?

• To prevent pressure build up in blow down line.
• In pipe burst, it may be injurious to watch keeper.

What if no test and treatments is done to boiler ?

• Reduction in boiler efficiency due to poor heat transfer
• Reduction in tensile strength
• Reduction in factor of safety
• Overheating of metal resulting distortion and eventual failure
• Increase in fuel consumption
• Excess concentration of NaOH (caustic soda) may cause caustic embrittlement on boiler metal and tend to failure of boiler metal
• Corrosion
• Scale formation
• Foaming, Priming, carry over (due to increase T.D.S level, foaming is present and tend to carried over and priming)

How to control steam pressure in exhaust gas boilers ?

1. By regulating the amount of gas flowing over the extended surface, i.e. by damper regulation.
2. By dividing the unit into sections so that each section is controlled by an inlet valve.
3. By passing steam through an automatic pressure controlled surplus valve to a dump condenser.
4. By a system designed for a higher pressure than that it is to operate.

What is meant by soot blow ?

• Purpose is to remove soot, to prevent EGE fire or soot fire.
• To get steam generating efficiency good
• To increase heat transfer efficiency
• Time – Day time at sea  2 -3 times/day

What is the procedure to soot blow ?

1. Inform to bridge
2. Check wind direction, good if transverse direction
3. Raise boiler pressure
4. Open drain cock until soot blow pipe drain clear
5. Open soot blower valve
6. Increase the air to boiler to more than 50 %
7. Open steam valve & carried out by turning wheel 20 -30 sec
8. Then close steam valve, soot blower valve 
9. Open drain valve

Boiler safety valve examination and attention during overhauling ?

• Checked its valve and valve seat for wear, cavity corrosion and any fault.
• They should be grounded properly but maker’s limit must be maintained such as width of seating, clearance between valve lip and seat.
• Valve chest must be cleaned condition and drain line clear.
• The spring should be hammer tested for any fracture and check for corrosion. Free length is limited to 0.5 % of original free length.
• The spindle should be hammer tested for any crack and its straightness.
• The guide plates and bushes are checked for uneven wear and have sufficient clearance to allow free movement of spindle.
• The compression nut and cover bush’s threads are carefully checked it for any sign of wear and tear.
• The easing gear should be checked in good order including bearings, cable pulley, and connecting links.
• Connecting pin should be a free fit in the lid and pin should not bent or pinhole gone out of shape.
• All safety valves are to be set to operate under steam a little above working pressure not greater than 3% above the approve working pressure of the boiler.

Why safety valve is fitted in two numbers  ?

• To make sure that the positive discharging of higher steam pressure from boiler efficiency.

Why fitted in one valve chest ?

• To reduce stress by hole on pressure vessel (boiler)
• To minimize the numbers of cutting hole on boiler to save it’s strength.