PIPE Elements 9

The low pressure cutout switch is operated by:
a. a magnet
b. a bellows
c. spring tension
d. water pressure

A good refrigerant should be
a. nonpoisonous
b. non-explosive
c. non-flammable
d. all of the above

If a refrigerating system extracted 48

The purpose of the low-pressure cutout switch is to
a. maintain liquid refrigerant at the suction of the compressor
b. maintain a present suction pressure to the compressor
c. cut out the compressor at set pressure
d. cut compressor in and out at a present pressure

The most likely cause of high superheat would be
a. too much refrigerant
b. expansion valve open too wide
c. expansion valve closed in too much
d. back-pressure valve set too high

The purpose of the evaporator is to
a. absorb latent heat of vaporization
b. absorb latent heat of fusion
c. transfer latent heat of vaporization
d. transfer latent heat of fusion

Air is removed from the system by
a. increasing the amount of cooling water
b. opening the purge valve
c. running the refrigerant through an aerator
d. running the refrigerant through a deaerotor

The suction pressure switch is operated by
a. electric current
b. thermocouple
c. pressure on bellows
d. a relay cutout

A hot suction line might be caused by
a. insufficient refrigerant
b. insufficient lubrication
c. expansion valve closed too much
d. too much refrigerant

The device used for low-pressure control and high-pressure cutout on a compressor is called a
a. cutout
b. pressure controller
c. controller switch
d. cutout switch

Thermal expansion valves are usually of the
a. bellows type
b. magnetic type
c. diaphragm type
d. A or C

Liquid reaching the compressor through the suction line is called
a. flooding back
b. superheating
c. overflowing
d. recycling

Pressure controllers are usually of the
a. diaphragm-type construction
b. bellows-type construction
c. magnetic-type construction
d. pilot-valve type construction

If the cooling water to the condenser should suddenly fail
a. the solenoid valve will close
b. the expansion valve will close
c. the compressor will shut down
d. an alarm will ring to notify the engineer

If the solenoid valve closed by accident

The solenoid valve controls the
a. amount of refrigerant entering the evaporator coils
b. amount of refrigerant going to the expansion valve
c. amount of refrigerant going to the compressor
d. pressure of the refrigerant going to the evaporator coils

As Freon passes through the expansion valve
a. the volume decreases and the pressure increases
b. the volume increases and the pressure increases
c. the pressure decreases and the volume increases
d. the volume decreases and the pressure decreases

When checking zinc plates in a condenser

if the compressor short cycles on high pressure cutout

In a refrigerating system the temperature is at its highest between the
a. condenser and receiver
b. compressor and condenser
c. receiver and evaporator
d. evaporator and compressor

A Freon unit will tend to short cycle when operating under
a. heavy loads
b. normal conditions
c. light loads
d. all of the above

Short-cycling means that the machine
a. grounds out frequently
b. stops and starts frequently
c. runs too fast
d. runs too slow

Freon is
a. non-corrosive
b. flammable
c. nontoxic
d. A and C

A refrigerant should have a
a. high latent heat
b. high sensible heat
c. low latent heat
d. low sensible heat

A method of reducing capacity without reducing compressor speed is called
a. low-pressure bypassing
b. high-pressure bypassing
c. hot-gas bypassing
d. short-cycling

The thermal expansion valve responds to the
a. amount of superheat in the vapor leaving the coil
b. amount of superheat in the liquid
c. temperature in th e evaporator coils
d. pressure in the evaporator coils

The bulb for the thermal expansion valve is located
a. in the middle of evaporator coils
b. near the evaporator coil outlet
c. near the evaporator coil inlet
d. on the bottom row of evaporator coils

A thermostat is a
a. temperature-operated switch
b. pressure-oriented switch
c. super-heat operated switch
d. back-pressure operated switch

The elements of thermostat switch are usually of the
a. diaphragm type
b. bimetal type
c. valve type
d. pilot-valve type

When heavy electrical currents are involved

If the compressor runs continually

The solenoid valve can be typed as a
a. thermal valve
b. magnetic stop valve
c. bellows valve
d. bimetallic valve

If the compressor had been running satisfactory

If the compressor had been running satisfactory for a long period of time but suddenly the compartment temperature started to rise

When charging a Freon system

Abnormal discharge temperatures would be caused by
a. leaky suction valves
b. leaky discharge valves
c. faulty piston rings
d. any of the above

A device for holding open the suction valve and drawing gas from the suction manifold and returning it to the suction line without compressing is is called
a. discharge line bypass
b. cylinder unloader
c. suction line bypass
d. relief valve

As heat is removed open the suction valve and drawing gas from the suction manifold and returning it to the suction line without compressing it is called
a. perfect zero
b. double zero
c. absolute zero
d. cold zero

The boiling point of water in an open container at sea level is 212⁰F. If the pressure on the open container is decreased

Another name for the liquid valve is the
a. master valve
b. king valve
c. Freon valve
d. shutoff valve

If the temperature in the icebox is too high

Oil is added to a Freon compressor by
a. pouring through oil hole in base
b. pumping in with a hand pump
c. pumping in with an electric-driven pump
d. shutting down the machine and pouring in through the crankcase inspection plate opening

If no gaskets are used in the piping joints of a Freon system

When adding oil to a Freon system one must be sure that
a. all air is removed from the pump and fittings
b. there is too high suction pressure
c. the discharge pressure is too high
d. the condenser is shutdown

If the head pressure is too high
a. the relief valve should open before the high-pressure cutout
b. the relief valve should open and let excess refrigerant valve opens
c. the high-pressure cutout switch should operate before relief vakve opens
d. close in on the suction valve

If the compressor-discharge temperature is higher than the receiver temperature
a. increase the amount of cooling water to the condenser
b. decrease the amount of cooling water to the condenser
c. add more refrigerant to the system
d. remove some of the refrigeration from the system

The dehydrator is used
a. to remove moisture from the system
b. to remove air from the system
c. when adding refrigerant to the system
d. A and C

If the discharge side of the thermal expansion valve is warmer than the inlet side

The oil level in the compressor should be checked
a. while the compressor is in operation
b. just before starting the compressor
c. after a long period of operation
d. B and C

The relief valve is located on the
a. discharge side of condenser
b. discharge side of compressor
c. outlet of the evaporator coils
d. receiver tank

The expansion valve on a Freon system controls the
a. superheat of the gas leaving the compressor
b. back pressure in the evaporator
c. temperature of the icebox
d. superheat of the gas leaving the evaporator

Thw scale trap is located between the
a. king valve and the expansion valve
b. solenoid valve and expansion valve
c. evaporator and receiver
d. compressor and evaporator

If the high-pressure switch on the compressor opens and stops the compressor

The capacity of a refrigerant unit can be regulated by
a. changing the speed of the compressor
b. changing the amount of cooling water to the condenser
c. changing the amount of refrigerant in the system
d. any of the above

which of the following would not cause high suction pressure?
a. insufficient refrigeration
b. leaky suction valves
c. expansion valve stuck open
d. suction valve not adjusted properly

All of the following are alloys of nickel except
a. K-monel
b. Inconel-X
c. Chromium molybdenum steel
d. Nichrome

If the compressor runs continuously

Dairy products should be kept at temperature of
a. 10⁰ to 20⁰
b. 20⁰ to 30⁰
c. 35⁰ to 45⁰
d. 15⁰ to 25⁰

The purpose of the expansion valve bypass is to
a. increase the efficiency of the plant
b. increase the capacity of the evaporator
c. control the refrigerant to the evaporator in case the automatic valves fall
d. bypass the compressor

Frost on the outside of the thermal expansion valve may be caused by
a. king valve and the expansion valve
b. receiver and the condenser
c. compressor and the receiver
d. evaporator coils and the compressor

The charging valve is located between the
a. king valve and the expansion valve
b. receiver and the condenser
c. compressor and the receiver
d. evaporator coils and the compressor

A high suction pressure and a cold crankcase indicate
a. air in the system
b. leaky suction valves
c. expansion valve open too wide
d. B or C

A high temperature in the icebox could not be caused by
a. insufficient refrigeration
b. air in the system
c. expansion valve open too wide
d. too much refrigerant in the system

When securing a Freon system for repairs
a. pump down to 1 or 2lbs pressure
b. pump down to a slight vacuum
c. pump down tob10 tob15 kbs pressure
d. remove all refrigerant from the system

The solenoid valve is located between the
a. scale trap and the thermal expansion valve
b. thermal expansion valve and the evaporator
c. king valve and the scale trap
d. automatic and manual expansion valves

When starting a refrigeration system

Before securing a compressor to do maintenance work on it

212⁰F is equal to
a. 106⁰C
b. 110⁰C
c. 100⁰F
d. 100⁰C

A good refrigerant should
a. have a low boiling point
b. have a high latent heat
c. be able to be liquified at normal seawater temperatures
d. all of the above

140⁰F is equivalent to
a. 50⁰C
b. 60⁰C
c. 40⁰C
d. 55⁰C

70⁰C is equivalent to
a. 150⁰F
b. 160⁰F
c. 158⁰F
d. 155⁰F

Low suction pressure is caused by
a. air in the system
b. leaky compressor suction valves
c. solenoid valve not functioning properly
d. expansion valve causing flooding back

The charging connection in a refrigerating system is located
a. before the receiver
b. between the condenser and the receiver
c. between the receiver and the king valve
d. between the king valve and the solenoid valve

Water tube boilers have
a. one fusible plug
b. no fusible plugs
c. two fusible plugs
d. none of the above

The valve that prevents water from backing out of the boiler into the feed line is the
a. bottom blow valve
b. skin valve
c. feed-check valve
d. feed-stop valve

The fuel oil heater is located
a. on the discharge side of the service pump
b. on the suction side of the service pump
c. on the discharge side of the transfer pump
d. between the settling tank and the service pump

Boilers"pulsations" are caused by
a. too high fuel pressure
b. insufficient air
c. forcing the boiler beyond capacity
d. all of the above

In the forced draft system
a. each furnace has its own fan
b. one fan supplies air to all furnaces
c. the fan is located in the uptake
d. none of the above

In the closed fire room system
a. each boiler has its own fan
b. each furnace has its own fan
c. the fan is located in the uptake
d. the fire room is supplied with air from one fan

The air cock on a boiler is located at the
a. end of the superheater
b. highest point of the steam and the water drum
c. superheater inlet
d. top of the return headers

Soot blowers should be used in proper sequence so that
a. excess stresses will not set up in the boiler
b. the deck will not be covered with soot
c. the soot will be swept toward the uptakes
d. there will not be a loss of steam pressure

What is the first thing you would check on taking over a watch?
a. the bilges
b. the periscope
c. the water level
d. the oil pressure

The boiler with its fan(blower) located in the uptake is operating on
a. induced draft
b. forced draft
c. natural draft
d. none of the above

A fire room that is completely isolated(closed) operates
a. induced draft
b. forced draft
c. natural draft
d. none of the above

How many feedwater lines are connected to the boiler?
a. one
b. two
c. three
d. four

If the water in the gage glass has not been blown down for a period of time

On taking over a watch

When you are cleaning fuel-oil burner tips

What is the amount of liquid in a tank if you get an ullage sounding of 11'4" and the empty ullage sounding of the tank is 32'2"?
a. 20'8"
b. 20'10"
c. 21'8"
d. 21'10"

The amount of steam generated by a boiler is dependent upon
a. the size of the sprayer plate
b. the oil pressure
c. the air pressure
d. all of the above

When installing a new gage glass in a water gage you should secure the bolts from
a. top of bottom
b. bottom of top
c. center

One of the main purposes of refractories in a boiler furnace is to
a. help preheat the air for the furnaces
b. help preheat the feedwater
c. protect economizer from excessive heat
d. prevent excessive furnace heat losses

All fuel-oil tanks are vented through
a. check vent to the settling tanks
b. gooseneck vent located on the main deck
c. check valve to the transfer pump
d. gooseneck vent which discharges to the settlers

All fuel-oil service pump steam valves are fitted with
a. safety locks
b. automatic controls
c. reach rods leading to a location outside the fire room
d. reach rods leading to the engine room

Which of the following fire extinguishers would not be found in the fire room?
a. foam type
b. sand
c. CO₂
d. SO₂

What isthe average fuel-oil temperature range of the oil in the discharge line to the burners
a. 180⁰ - 200⁰
b. 150⁰ - 180⁰
c. 200⁰ - 220⁰
d. 150⁰ - 200⁰

Which of the following is a common type of oil burners?
a. Bethlehem
b. Todd
c. B&W
d. all of the above

The boiler gage glasses should be blown down
a. once a day
b. at the beginning of every watch
c. every 12 hours
d. every 8 hours

Gage pressure of 200 lbs per square inch is equivalent to what absolute pressure?
a. 215
b. 200
c. 185
d. 300