OIC-EW MARINA REVIEWER / QUIZ COMPETENCE 4 - PART 1 - Seaman Kowts

COMPETENCE 4 -Operate Main and Auxiliary Machinery and – Associated Control Systems

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#1. An unloader is installed on an air compressor to:

bypass the high pressure stage to the low pressure stage on 100% of the air compressors in service

prevent excessive interstage pressure buildup

control compressor discharge pressure

remove all but the frictional load during starting

Incorrect!

#2. What is the color coding for a storage container of R-134a refrigerant?

green

light blue

grey

purple

Incorrect!

#3. A refrigerant used in a mechanical refrigeration system should have which of the following characteristics?

High boiling point

High freezing poi

Low specific heat

Low boiling point

Incorrect!

#4. If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, the _________.

purifier will act as a clarifier at the discharge ring

oil will be lost through the water discharge ports

oil solids will be deposited only at the intermediate top disk

oil has a tendency to emulsify in the bowl

Incorrect!

#5. An air compressor is equipped with an intercooler and an aftercooler to _______.

prevent overheating of first stage valves

reduce the compressed air charge density

increase compressor efficiency

inject water vapor into the compressed air

Incorrect!

#6. The rupture disc used on low pressure refrigerant storage containers is set for what pressure?

15 psig

1 psig

5 psig

10 psig

Incorrect!

#7. What component of the freshwater evaporator on board use to boil seawater, using the main engine jacket cooling water?

Shell

Evaporator

Ejector

Condenser

Incorrect!

#8. Cylinder oil is used for ________.

2-stroke engine

4-stroke and 2 stroke engine

4-stroke engine

gasoline engine

Incorrect!

#9. The heat removed from the refrigerant in the condenser of a refrigeration plant is known as what?

latent heat of expansion

heat of compress

sensible heat of condensation

all of the above

Incorrect!

#10. If a liquid drying agent is used in a refrigeration system already equipped with a solid drying agent, the liquid drying agent will cause what type of reaction?

it will release the moisture already trapped in the solid drying agent

it will react violently with the solid drying agent

it will cause toxic gases to form in the refrigerated space

it will solidify the refrigerant oil in the compressor crankcase

Incorrect!

#11. Thermostatic expansion valves can be adjusted for which of the following?

suction pressure only

head pressure only

suction pressure and box temperature

evaporator superheat only

Incorrect!

#12. Which of the following statements is correct concerning heat transfer?

Heat is given off from a high temperature region known as a heat sink.

Heat transfer surfaces are being layered with scale.

Impure distillate is being produced.

Shell vapor pressure is constantly decreasing.

Incorrect!

#13. When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, what should be done to compensate for or to correct this situation?

increase the amount of cooling water to the condenser

decrease the amount of cooling water to the condenser

raise the high pressure cut-out opening pressure

remove some refrigerant from the system

Incorrect!

#14. One of the primary steps in assisting someone who has been overcome by ammonia vapors is to do what?

loosen all clothing

provide the victim with smelling salts

give the patient plenty of fresh air

rinse the affected area with water

Incorrect!

#15. In a refrigeration system, at what component does the refrigerant absorb the latent heat of vaporization?

compressor

condenser

evaporator

receiver

Incorrect!

#16. If a condenser coil of an air-cooled container refrigeration system becomes dirty and requires cleaning, what would be an acceptable method of cleaning?

‘Binks’ gun with weak acid solvent

high pressure water wash

copper wire rotary brush

All of the above

Incorrect!

#17. Cylindrical, replaceable silica gel core dehydrators installed in halocarbon refrigerant systems are typically arranged in what way?

so that the liquid enters at the top and leaves at the bottom when located vertically in the liquid line

so that the liquid enters at the bottom and leaves at the top when located vertically in the liquid line

horizontally if a liquid drying agent is also used

horizontally if the drying agent is calcium oxide

Incorrect!

#18. A one ton air conditioning system has which of the listed operating characteristics?

It forces 2,000 lbs. of refrigerant through the evaporator coil per day.

It forces 2,000 lbs. of air per hour across the evaporator coils

It has the cooling capacity equivalent to melting 2,000 lbs. of ice per day.

It has the cooling capacity equivalent to melting 2,000 lbs. of ice per hour.

Incorrect!

#19. The high pressure cut-out switch will stop the refrigeration compressor when there is _______.

accumulation of refrigerant in the crankcase oil

restricted suction filter

lack of refrigerant

a stoppage of condenser cooling water flow

Incorrect!

#20. One of the major components of centrifugal pump is ___________.

gear

screw

impeller

piston

Incorrect!

#21. Which refrigeration system will absolutely require the use of an oil separator located in the discharge line due to a lack of refrigerant oil miscibility?

R-401A

R-717 (ammonia

R-134a

R-22

Incorrect!

#22. Which of the fluids listed is normally used to condense the primary refrigerant in an indirect shipboard central air conditioning system?

Engine jacket water

Seawater or Fresh water

Sodium Nitrate br

Calcium Sulfate brine

Incorrect!

#23. The advantages of flash type evaporators, as compared to submerged tube type evaporators, include:

less hard scale formation in a flash evaporator

less internal corrosion because of lower brine density

higher temperature evaporation for lower salinity of the distillate produced

less feed water required for a flash evaporator

Incorrect!

#24. Which of the valves listed is normally closed when charging the refrigeration system through the high side?

Dehydrator inlet valve

Liquid line king valve

Suction line valve

Thermal expansion valve

Incorrect!

#25. Increasing the moisture content of conditioned air is known as what?

moisturizing

dehumidification

dampening

humidification

Incorrect!

#26. Refrigerant enters the condenser in what condition?

high pressure liquid

low pressure vap

low pressure liquid

high pressure vap

Incorrect!

#27. In a two stage flash type evaporator, the brine overboard pump is vented directly to the:

saltwater heater shell

first stage distilling condenser

second stage flash chamber

air ejector condenser

Incorrect!

#28. Excessive moisture being collected in the purge unit of a low pressure refrigeration system could indicate which probable condition?

leaking condenser or chiller tubes

low efficiency purge unit

dryer core needs replacement

improper charging of refrigerant

Incorrect!

#29. In a large refrigeration system having more than one evaporator, a king solenoid valve should be installed in what location?

just after the receiver

before the condenser

between the condenser and receiver

before the back pressure regulating valve

Incorrect!

#30. During the operation of a five box refrigeration system, using a fixed capacity compressor, two additional boxes came on line with the two boxes already in the active cooling process. At the beginning of the cooling period for the two additional boxes, the operating conditions of the system would require the quantity (flow rate) of refrigerant to the compressor suction to do what?

increase, with an increase in suction pressure

remain the same, with a decrease in suction pressure

increase, while maintaining the previous suction pressure

remain the same with an increase in suction pressure

Incorrect!

Finish

There are 30 questions for the actual examination for Competence 4 for OIC-EW with a passing rate of 70%. This means that you are only allowed to make 9 mistakes.

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Results

#1. An unloader is installed on an air compressor to:

#2. What is the color coding for a storage container of R-134a refrigerant?

#3. A refrigerant used in a mechanical refrigeration system should have which of the following characteristics?

#4. If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, the _________.

#5. An air compressor is equipped with an intercooler and an aftercooler to _______.

#6. The rupture disc used on low pressure refrigerant storage containers is set for what pressure?

#7. What component of the freshwater evaporator on board use to boil seawater, using the main engine jacket cooling water?

#8. Cylinder oil is used for ________.

#9. The heat removed from the refrigerant in the condenser of a refrigeration plant is known as what?

#10. If a liquid drying agent is used in a refrigeration system already equipped with a solid drying agent, the liquid drying agent will cause what type of reaction?

#11. Thermostatic expansion valves can be adjusted for which of the following?

#12. Which of the following statements is correct concerning heat transfer?

#13. When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, what should be done to compensate for or to correct this situation?

#14. One of the primary steps in assisting someone who has been overcome by ammonia vapors is to do what?

#15. In a refrigeration system, at what component does the refrigerant absorb the latent heat of vaporization?

#16. If a condenser coil of an air-cooled container refrigeration system becomes dirty and requires cleaning, what would be an acceptable method of cleaning?

#17. Cylindrical, replaceable silica gel core dehydrators installed in halocarbon refrigerant systems are typically arranged in what way?

#18. A one ton air conditioning system has which of the listed operating characteristics?

#19. The high pressure cut-out switch will stop the refrigeration compressor when there is _______.

#20. One of the major components of centrifugal pump is ___________.

#21. Which refrigeration system will absolutely require the use of an oil separator located in the discharge line due to a lack of refrigerant oil miscibility?

#22. Which of the fluids listed is normally used to condense the primary refrigerant in an indirect shipboard central air conditioning system?

#23. The advantages of flash type evaporators, as compared to submerged tube type evaporators, include:

#24. Which of the valves listed is normally closed when charging the refrigeration system through the high side?

#25. Increasing the moisture content of conditioned air is known as what?

#26. Refrigerant enters the condenser in what condition?

#27. In a two stage flash type evaporator, the brine overboard pump is vented directly to the:

#28. Excessive moisture being collected in the purge unit of a low pressure refrigeration system could indicate which probable condition?

#29. In a large refrigeration system having more than one evaporator, a king solenoid valve should be installed in what location?

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