MEO Class 4 Exam Questions and Answers 2020 – Section 3

MEO Class 4 Exam Questions and Answers 2020 – Section 3

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1. Evaporator pressure testing in (multiple choice)

  • Pr. testing in shell
  • Leak test in vacuum pump and fittings
  • leak test in distillate pump
  • Vacuum testing in shell

2. PLATE type heat exchanger is preferred for following advantage

  • high heat transfer
  • easy to clean 
  • increased time between clean 
  • all

3. For carrying out major work in tank –

  • First aid in entrance 
  • refreshment 
  • entry/exit time of personnel 
  • all

4. Increasing the rotational speed of a cargo pump the pump flow rate will:

  • Increase in direct proportion to the increase in speed
  • A decrease in direct proportion to the increase in speed
  • The flow rate doesn’t depend upon the speed

5. Boiler water level control, controlling swell and shrink of the boiler with

  • feedwater level
  • steam drum
  • water drum
  • none of the above

6. The pressure produced within the oil wedge of a rotating journal is ____.

  • the same as the pressure in the lubricating system
  • less than the pressure in the lubricating system
  • greater than the pressure in the lubricating system
  • highest at the oil groove location

7. Which of the main shaft segments listed below, that are connected with the main engine, are coupled to the tail shaft flange?

  • Thrust shaft
  • Stern-tube shaft
  • Intermediate shaft
  • Crankshaft

 8. Piping cross-sections over 30 cm in diameter are sized by the __________.

  • inside diameter
  • wall thickness
  • outside diameter
  • threaded diameter

9. Fabric type packing, such as flax or hemp, is best suited for _____________.

  • low-temperature use
  • high-temperature use
  • use where alignment is critical
  • packing valves with badly grooved stems

10. The ambient heat in an engine room which is identified by only a change in temperature is known as 

  • sensible heat
  • latent heat
  • total heat
  • residual heat

11. The usual number of single-acting pistons used in a variable stroke axial-piston pump used for steering gears is _____________.

  • 3 or 5      
  • 5 or 7
  • 7 or 9
  • 9 or 11

12.Heavy soot accumulations in an Auxiliary Boiler could be caused by _____  

  • water in the fuel oil                                                 
  • excessive cycling                                                     
  • high fuel oil pressure                                              
  • improper burner maintenance                                          


13.An axial piston pump differs from a radial piston pump, like the pistons of an axial piston pump, is positioned _________.

  • radially from the shaft
  • parallel to each other and to the shaft
  • parallel to each other but at a right angle to the shaft
  • at an angle to each other and to the shaft

14. In reference to air conditioning, when air attains the maximum amount of moisture it can hold at a specific temperature, it is said to be _____________.

  • superheated
  • saturated
  • condensed
  • convected

15. Positive displacement, helical gear pumps are well suited for pumping oil because 

  • stuffing boxes eliminate the leakage problems usually associated with other gear pumps
  • it is not necessary to closely maintain design clearances this pump
  • they are essentially self-priming and produce a high suction lift
  • these pumps are designed with extreme tooth angles

16. The conical steel or composition cone installed on a propeller, known as a fairwater cone, provides which of the following benefits?

  • Reduce turbulence
  • Help with lubrication 
  • Protect against electrolytic corrosion
  • All of the above

17. It is desirable for an auxiliary boiler safety valve to pop open and reseat quickly to give warning that excessive boiler pressure has been reached


  • prevent wire drawing of the disc and seat  
  • prevent valve pounding                                        
  • provide sufficient blowdown                                           


18. The purpose of the programmed purge cycle on an automatically fired auxiliary boiler is to

  • cool the furnace to prevent pre-ignition
  • remove explosive vapors from the furnace
  • evaporate accumulated unburned fuel oil
  • provide sufficient air in the furnace to allow ignition of the fuel

19. Short cycling of a refrigeration compressor refers to _____________.

  • Frequently cutting out on overload.
  • frequently starting and stopping
  • running too fast
  • running too slow

20. The emergency bilge suction valve is typically used _____________.

  • to inject cleaning additives when the bilges are extremely dirty
  • when the main condenser becomes fouled, in order to provide additional cooling water circulation
  • to connect the rose box to the independent bilge suction
  • if the bilges become flooded and they cannot be emptied by any other means

21. The by-products of oxidation, as a result of water contamination of hydraulic oil, are generally ____________.

  • removed by cellulose type filters
  • gums, varnishes, and acids
  • always neutralized by oil additives
  • harmless and have no effect on the system components

22. Which of the following describes the purpose of a striker or doubler plate?

  • Provides a surface for the application of force, or the installation of machinery.
  • Provides landing surface for the sounding bob of a tank sounding tape.
  • Absorbs machinery vibration.
  • Prevents valve stem over travel.

23. Which of the following statements represents the proper relative direction of flow through a globe valve?

  • The direction of flow through the valve is unimportant.
  • The direction of flow through the valve depends upon the type of seat design used in the valve.
  • The direction of flow should be from below the seat.
  • The direction of flow should be from above the seat.

24. A portion of the cargo of an LNG carrier boils off during each voyage. How the cargo boils off is normally handled?

  • Compressed, condensed, and returned to the cargo tanks.
  • Vented to the atmosphere.
  • Burned in the boilers.
  • Mixed with nitrogen and recirculated through the primary barrier.
  • Burnt off in a controlled manner through a chimney smokestack from within the funnel.

25. In-Vessel construction, beam brackets are triangular plates joining the deck beam to a 

  • bulkhead
  • frame
  • stanchion
  • deck longitudinal

26. The cylinders and intercoolers of most low pressure air compressors are cooled by  

  • water
  • oil
  • air
  • CO2

27. A one-ton air conditioning system has which of the listed operating characteristics?

  • It forces approximately 1000kgs of refrigerant through the evaporator per day.
  • It forces approximately 1000kgs of air per hour across the evaporator coils.
  • It contains approximately 1000kgs of refrigerant.

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

  • Copper.
  • Copper and carbon.
  • Carbon.
  • Bronze.

29. When using a handheld hacksaw, you should apply pressure only on the forward stroke ____________.

  • only when cutting thin wall tubing
  • only when cutting carbon steel
  • only when cutting conduit
  • at all times

30. An important consideration in selecting a lubricating oil for use in a refrigeration compressor is for the oil to ____________.

  • have a high viscosity index
  • mix readily with refrigerant
  • have a high freezing point
  • have a low pour point

31. If the intercooler relief valve lifts while an air compressor is operating under load, you should check for ____

  • a defective pressure switch or pilot valve
  • a leak in the intercooler piping
  • leakage through the low-pressure unloader control diaphragm
  • leaking high pressure discharge valves

32. Latent heat can be defined as the heat which must be added to a substance in order to change it from a

  • solid to liquid
  • liquid to vapor
  • solid to vapor
  • all of the above

33. The designation “schedule 80 extra strong ” refers to ____________.

  • weight of steel plate
  • tensile strength of bolts
  • piping wall thickness
  • tube bursting strength

34. Tapping threads into a blind hole should be finished by using a ______

  • short tap
  • taper tap
  • plug tap
  • bottoming tap

35. Distilled water from an evaporator maybe discharged into a potable water tank 

  • through a detachable hose connection
  • after passing through an activated charcoal filter
  • after chemical analysis shows it is fit for consumption
  • through a solenoid operated three-way valve

36. The factors that determine the service life of packing in a pump will include which of the following conditions?

  • type of pump
  • condition of the shaft
  • length of time in use
  • all of the above

37. Personnel working with refrigeration systems and subject to the exposure of refrigerants should wear _______________.

  • face shield
  • a respirator
  • rubber gloves
  • an all-purpose gas mask

38. Which of the listed problems is occurring if a coil type high-pressure evaporator constantly requires an increase in the coil steam pressure in order to maintain capacity?

  • The brine density is improper.
  • Heat transfer surfaces are being layered with scale.
  • The impure distillate is being produced.
  • Shell vapor pressure is constantly decreasing.



39. The ability of a metal to be hammered, or rolled out is called its ___________.

  • ductility
  • elasticity
  • malleability
  • fusibility

40. One characteristic of a lubricating oil adversely affecting the results of centrifuging is ____________.

  • high TBN value
  • low oil floc point
  • low oil Demulsibility
  • low oil neutralization number

41. Which of the devices listed prevents water from entering a ship’s hull via the propulsion shaft?

  • Stern tube packing or mechanical shaft seal
  • Deflector ring and drain
  • Spring bearings
  • Oiler rings

42. With reference to a vessel’s structural integrity, the most significant characteristic of a cryogenic liquid is its ______________.

  • capability of causing brittle fractures
  • highly corrosive action on mild steel
  • vapor cloud which reacts violently with saltwater
  • toxicity at atmospheric pressure

43. The heat required to change a substance from a solid to a liquid while at its freezing temperature, is known as the latent heat of _____________.

  • fusion
  • vaporization
  • condensation
  • sublimation

44. Which of the following problems occurring in a hydraulic system can be caused by the use of an oil having a viscosity lower than specified?

  • Seal deterioration
  • Fast response and hunting
  • Increased power consumption
  • Oil film breakdown

45. The only means of removing the latent heat of condensation from a refrigerant in the normal refrigeration cycle is by ________.

  • passing it through the expansion valve
  • condensing the refrigerant in the system condenser
  • passing the gaseous refrigerant through the heat interchanger on the suction side of the compressor
  • maintaining a high pressure on the system’s receiver

46. Which of the following statements represents the main difference between a stuffing box gland and a mechanical seal for sealing the shaft of a centrifugal pump?

  • Packed stuffing box glands are subject to wear, but mechanical seals are not.
  • Packed stuffing box glands must be cooled by the liquid being pumped, but mechanical seals do not require cooling.
  • If packing fails, the pump can be kept running temporarily by tightening the gland, but if a mechanical seal fails it must be totally renewed to stop the leakage.
  • The sealing surface of a mechanical seal is parallel to the shaft, but the sealing surface of a packed gland is perpendicular to the shaft.

47. In a shell-and-tube type hydraulic fluid cooler, the amount of heat transferred from the hydraulic fluid to the cooling water depends upon ________________.

  • the temperature of the hydraulic fluid
  • the flow rate of both the cooling water and the hydraulic fluid
  • the temperature of the cooling water
  • all of the above

48. The presence of scale and dirt on the saltwater side of lube oil cooler is usually indicated by ___________.

  • clogged lube oil strainers
  • seawater leaking into the lube oil system
  • decreasing lube oil pressure
  • gradually increasing lube oil temperature

49. The charging of a refrigerating system should be carried out by adding _____________. 

  • refrigerant vapor to the receiver only
  • liquid refrigerant to the low side only
  • liquid refrigerant to the high side only
  • liquid refrigerant to the high or low side

50. A leaking suction valve in the second stage of a two-stage, high pressure, Air compressor can cause excessively high ________________.

  • second stage discharge pressure
  • first stage discharge pressure
  • pressure in the after cooler
  • compressor final discharge temperature

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