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FINAL PWEN ABSA PRACTICE 3 > FINAL PWEN ABSA PRACTICE 3 > Flashcards

FINAL PWEN ABSA PRACTICE 3 Flashcards

1
Q

A large reaction turbine will have:

a. No thrust bearings.
b. Steam pressure dropping in only the moving sections.
c. Steam pressure dropping through moving and stationary sections.
d. Never more than 5 stages.
e. Blades that are basically symmetrical in cross-sectio

A

c. Steam pressure dropping through moving and stationary sections.

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2
Q

An essential auxiliary in a gas turbine installation is a/an:

a. Air heater
b. Generator
c. Air dehumidifier
d. Pump
e. Starting motor.

A

e. Starting motor.

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3
Q

If you desire an oil to flow at a much lower temperature, you would most likely add:

a. A viscosity index improver
b. Pour point depressants
c. A dispersant
d. A thickening agent
e. Low viscosity oil.

A

b. Pour point depressants

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4
Q

Impulse turbines:

  1. Have a velocity increase through the nozzles
  2. Blades have the angle of inlet the same as the outlet
  3. Could have more than one set of blades
  4. Are used for low pressure steam only
  5. May not require a thrust bearing

a. 1, 2, 3, 4
b. 2, 3
c. 1, 3, 4, 5
d. 2, 3, 4
e. 1, 2, 3, 5

A

e. 1, 2, 3, 5

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5
Q

An anti-friction bearing:

  1. Is a bearing containing white metal alloy
  2. Has rolling friction
  3. Could be a thrust bearing
  4. Is a sleeve bearing

a. 1, 4
b. 1, 2, 3
c. 2, 3, 4
d. 2, 3
e. 3, 4

A

d. 2, 3

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6
Q

Four-cycle engine lubrication is usually:

a. Forced by a pump
b. By gravity oilers
c. By the scoop method
d. By the dip tube method
e. By grease fitting

A

a. Forced by a pump

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7
Q

In a compression ignition engine, the fuel is ignited by:

a. An electric spark
b. The compressed air temperature
c. The atomized fuel
d. A cross-combustor
e. Compressed air pressure.

A

b. The compressed air temperature

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8
Q

A double-acting pump:

a. Has two pistons on the pump end
b. Will always be driven by the steam pistons
c. Has two pistons on the driver end
d. Will have two slide valves
e. Is a positive displacement pump.

A

d. Will have two slide valves

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9
Q

A thrust bearing which does not utilize the oil wedge principle of lubrication is the:

a. Michell type
b. Collar type
c. Flotation type
d. Kingsbury type
e. Vertical type

A

b. Collar type

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10
Q

Proper priming and venting of a pump is important, especially if:

a. The medium being pumped is high temperature
b. The medium being pumped contains suspended solids
c. Oil or other low flash point lubricant is being pumped
d. A mechanical seal is used
e. The pump has a stuffing box and lantern ring.

A

d. A mechanical seal is used

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11
Q

A centrifugal pump:

a. Will work well with a negative suction head
b. Can discharge to a very high elevation
c. Can lift a fluid from very deep wells
d. Needs a lantern ring when the suction head is low
e. Is mainly used with lubrication systems

A

d. Needs a lantern ring when the suction head is low

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12
Q

Strainers are found:

a. On the suction side of the pump
b. On the discharge side of the pump
c. Inside the pump
d. On the air vent discharge of the pump
e. In the impeller eye of the pump.

A

a. On the suction side of the pump

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13
Q

Positive displacement compressors:

a. Could be of the centrifugal type
b. Require a positive water seal
c. Must all use cylinder valves
d. Must all use internal lubrication
e. Could be single stage with three cylinders.

A

e. Could be single stage with three cylinders.

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14
Q

When inspecting a dismantled bearing, the first indication of a failing bearing is:

a. Cracked balls
b. Roughness
c. Discoloration
d. Rusting or corrosion
e. Tapered rollers.

A

b. Roughness

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15
Q

A gas turbine performs most effectively if the:

a. Lubricating oil is of the proper viscosity
b. Cooling water temperature is kept low
c. Ambient air temperature is high
d. Ambient air temperature is low
e. Load is added immediately after startin

A

d. Ambient air temperature is low

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16
Q

The characteristics of good grease are largely determined by:

a. Its thickening agent or “soap”
b. Its consistency
c. The type of oil used in the grease
d. Its protective coating e. Its color

A

a. Its thickening agent or “soap”

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17
Q

The purpose of a thrust bearing is to:

a. Prevent the shaft from moving with the thrust
b. Prevent the shaft from rotating backwards due to thrust
c. Prevent the shaft from moving in the opposite direction from the thrust
d. Prevent the shaft from excessive stress due to torsion force
e. Create thrust in the opposite direction

A

a. Prevent the shaft from moving with the thrust

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18
Q

The purpose of turbine glands is to prevent:

a. Water from entering the turbine
b. Steam from entering the turbine
c. Steam escaping from the turbine
d. Steam from entering the lubrication system
e. Oil from entering the turbine

A

c. Steam escaping from the turbine

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19
Q

When replacing or removing an anti-friction ball bearing, the applied force should:

a. Not be transmitted through the bearing balls
b. Always be against the inner race
c. Always be against the outer race
d. Be applied suddenly and fully
e. Be made only after heating the bearing

A

a. Not be transmitted through the bearing balls

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20
Q

The capacity of a centrifugal pump should only be reduced by:

a. Throttling the suction valve
b. Closing the suction valve
c. Closing both suction and discharge valves
d. Opening the pump casing vent valve
e. Throttling the discharge valve

A

e. Throttling the discharge valve

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21
Q

An open circuit is one in which:

a. A switch is closed
b. The current flows through the resistance
c. The wires are bare
d. A switch is open
e. Voltage may exit.

A

d. A switch is open

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22
Q

An insulator is, a material that will not _____ an electrical current:

a. Reduce
b. Retard
c. Resist
d. Slow
e. Conduct

A

e. Conduct

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23
Q

The equivalent resistance of three resistances of 10 ohms, 25 ohms and 50 ohms connected in parallel is _____ ohms.

a. 0.16
b. 6.25
c. 85
d. 18.75
e. 8.5

A

b. 6.25

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24
Q

Watt meters measure:

a. Apparent power
b. Power factor
c. Resistance to current flow
d. Coulombs
e. True watts

A

e. True watts

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25
Q

What power is dissipated by a resistor with a supply voltage of 120 volts and a current of 8 amperes?

a. 960 ohms
b. 15 ohms
c. 15 watts
d. 960 watts
e. 96 kilowatts

A

d. 960 watts

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26
Q

A “control” should be considered as a special device which:

a. Sends or transmits a positive rather than negative signal
b. Tries to maintain a set point
c. Leaves a hard copy record of a system’s performance
d. Notifies operators of errors or faults in a system
e. Is a logic device capable of making decisions

A

c. Leaves a hard copy record of a system’s performance

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27
Q

Synchronous motors have construction that is identical to:

a. Reciprocating equipment
b. Gas turbines
c. Air driven motors
d. Centrifugal fans
e. Alternators.

A

e. Alternators.

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28
Q

Low pressures and vacuums may be measured:

a. With a transducer
b. With a controller
c. In tonne
d. With a manometer
e. In Newton’s.

A

d. With a manometer

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29
Q

A sensing element sends its signal to a:

a. Transmitter
b. Sender
c. Conveyer
d. Express
e. Recorder

A

a. Transmitter

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30
Q

The voltage produced in each phase of a three phase generator is displaced by _____ electrical degrees from the other phases:

a. 120
b. 90
c. 60
d. 30
e. 0

A

a. 120

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31
Q

When magnetic flux produced by one coil induces an EMF in a second coil, it is called:

a. Self inductance
b. Electromagnetic induction
c. Mutual inductance
d. Capacitive reactance
e. Inductive reactance

A

c. Mutual inductance

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32
Q

The most universal high level language is:

a. Beginner
b. Fortran
c. Pascal
d. Cobol
e. Basic.

A

e. Basic.

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33
Q

Burner light oil supply pressure range is approximately:

a. 50 to 100 kPa
b. 150 to 250 kPa
c. 300 to 550 kPa
d. 550 to 700 kPa
e. 700 to 850 kPa

A

d. 550 to 700 kPa

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34
Q

When using mechanical fuel oil atomization:

a. 70 kPa steam pressure is required at the burner
b. Dry saturated steam or superheated steam should be used
c. High pump pressure is required
d. Steam pressure is required to keep the bypass open e. 35 to 40 kPa oil pressure is required.

A

c. High pump pressure is required

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35
Q

The _____ pilot is most often used on a small boiler.

a. Interrupted
b. Intermittent
c. Automatic
d. Manual
e. Continuous

A

e. Continuous

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36
Q

The output voltage of a shunt DC generator may be varied by adjusting the:

a. Field rheostat
b. Brakes
c. Output current
d. Number of poles
e. Main breaker disconnec

A

a. Field rheostat

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37
Q

A current carrying conductor being moved by a magnetic field is the principle known as:

a. Magnetic flux
b. Electrolysis
c. Hydro-electrics
d. Generator action
e. Motor action.

A

e. Motor action.

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38
Q

A hydramotor valve:

a. Opens and closes quickly
b. Helps to prevent puff-backs
c. Uses air as its working medium
d. Should not be the last fuel valve to open
e. Closes slowly

A

b. Helps to prevent puff-backs

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39
Q

Hot water boilers have stop valves in their inlet and outlet piping:

a. To allow for better warm ups
b. To prevent water from entering another in-service unit
c. So that each boiler can have separate water treatment
d. So that the boiler can be drained without draining the system
e. To permit annual maintenance

A

d. So that the boiler can be drained without draining the system

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40
Q

Rust in the water gage glass is an indication that:

a. Suspended solids are high
b. Raw water is leaking into the boiler
c. The copper and brass seats of the valves are deteriorating
d. Corrosion is occurring in the system
e. Total dissolved solids in the boiler are high

A

d. Corrosion is occurring in the system

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41
Q

A low water fuel cutoff switch should close the automatic fuel valve(s) on a heating boiler when the water level is:

a. At the lowest permissible water line
b. At the lowest visible part of the water gage glass
c. 1 to 2.5 cm above the bottom gauge glass nut
d. 1 to 2.5 cm below the gauge glass nut
e. 76 mm above the lowest permissible water line

A

b. At the lowest visible part of the water gage glass

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42
Q

Before lighting off a boiler you should always purge the furnace in order to:

a. Prove that the furnace and stack are clear
b. Blow out any soot that may have collected in the tubes
c. Cool the furnace so that premature combustion can occur
d. Remove any combustible gases that may have collected
e. Dry out the brickwork and check for leaks

A

d. Remove any combustible gases that may have collected

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43
Q

The vacuum pump performs the following function:

a. Supplies water to the condensate receiver
b. Supplies steam to the boiler
c. Returns the condensate (water) back to the boiler
d. Returns the steam to the condensate receiver
e. None of the above

A

c. Returns the condensate (water) back to the boiler

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44
Q

Air vents are used to:

a. Trap excess air
b. Expel the air from heating systems
c. Trap volatile liquids
d. Expel impurities from boilers
e. Expel the moisture from heating systems.

A

b. Expel the air from heating systems

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45
Q

The Hartford Loop prevents the water in the boiler from:

a. Exceeding the maximum temperature
b. Exceeding the highest safe level
c. Dropping below a safe level
d. Contamination by impurities in the returning condensate
e. Flowing out through the steam main.

A

c. Dropping below a safe level

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46
Q

In order to keep salt concentrations within safe limits, the packaged tubular steam boiler utilizes:

a. An automatic blow down
b. A desalinater
c. A water softener after the condensate receiver
d. A mixing chamber before the heating coil
e. A liquid flow control device

A

a. An automatic blow down

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47
Q

A hot water boiler of the same output is:

a. Larger than a steam boiler
b. Smaller than a steam boiler
c. The same size as a steam boiler
d. Taller than a steam boiler
e. Shorter than a steam boiler

A

b. Smaller than a steam boiler

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48
Q

If a conductor is forced to _____ magnetic lines of force, an electromotive force is induced in the conductor.

a. Block
b. Reduce
c. Cut
d. Increase
e. Remove

A

c. Cut

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49
Q

Open type expansion tanks:

a. Must be located below the heating system
b. Must be located above the heating system
c. Are used with large hot water boilers only
d. Are used with small hot water boilers only
e. Must be located indoor

A

b. Must be located above the heating system

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50
Q

Circulating pumps used in hot water heating systems are usually:

a. Reciprocating pumps
b. Gear type pumps
c. Rotary pumps
d. Centrifugal pumps
e. Regenerative pumps

A

d. Centrifugal pumps

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51
Q

The expansion tank is normally attached to the:

a. Boiler or the hot water supply line near the boiler
b. Highest point in the system directly above the boiler c. Supply line after the circulating pump
d. Supply line above the lowest convector
e. Return line directly before the boile

A

a. Boiler or the hot water supply line near the boiler

52
Q

A type of directly fired space heater is:

a. A unit heater
b. A floor furnace
c. A wall furnace
d. All of the above.
e. None of the above

A

d. All of the above.

53
Q

If during startup the pilot fails to ignite a lockout switch will be deenergized:

a. After a trial period of 15 to 30 seconds
b. Immediately
c. Within 4 or 5 seconds
d. After the flame relay de-energizes
e. After the main burner flame ignites.

A

a. After a trial period of 15 to 30 seconds

54
Q

Furnace heat exchangers should be checked for corrosion because:

a. Carbon monoxide could leak into the building
b. The holes reduce the furnace efficiency
c. Cold air could leak into the building
d. The air will become too dry for comfortable heating
e. Too much air would enter the furnace

A

a. Carbon monoxide could leak into the building

55
Q

Mechanical filters can be divided into two broad classes:

a. Wet and dry
b. Rotating and stationary
c. Dry and viscous
d. Corrugated and smooth
e. Throwaway and renewable.

A

e. Throwaway and renewable.

56
Q

What is the purpose of the high limit temperature control on a hot water boiler?

a. To take over operating the boiler if the water level control fails.
b. To allow you to take off the operating control for maintenance without shutting down the boiler.
c. To shut down the burner if the water temperature rises too high.
d. To prevent the pressure in the boiler rising above 210 kPa gage.
e. To limit high pressure and temperature from developing.

A

c. To shut down the burner if the water temperature rises too high.

57
Q

One type of flame failure device uses a lead sulphide cell that is sensitive to:

a. Temperature
b. Infrared rays
c. Ultraviolet rays
d. The color of the fuel
e. Radio waves.

A

b. Infrared rays

58
Q

With single element feed water control, the level transmitter output is:

a. Received by a final element
b. Proportional to drum level
c. Sent to a selector station
d. Constant, regardless of level
e. A function of steam flow.

A

b. Proportional to drum level

59
Q

Before starting up a new boiler or one that has been out of service the following must be ensured:

a. The manufacturer’s recommendations are read
b. The boiler has a valid inspection certificate
c. The fuel is shut off
d. The boiler control is in the off position
e. The boiler is cold

A

b. The boiler has a valid inspection certificate

60
Q

Most breaker cubicles and motor starter cubicles are operated so that:

a. The door opens to the left
b. The door cannot be opened from the outside
c. The breaker or disconnect switch must be tripped to its open position before the door is opened
d. They will not allow the contents to be overheated
e. The contents are easily visible

A

c. The breaker or disconnect switch must be tripped to its open position before the door is opened

61
Q

According to the current ASME code, steam heating boilers shall have one or more safety valves and adjusted and sealed to discharge at a pressure not exceeding _____ kPa.

a. 100
b. 101
c. 110
d. 103
e. 105

A

a. 100

62
Q

The sections of cast iron boilers are mainly designed to obtain maximum:

a. Water space
b. Steam space
c. Water circulation
d. Heat transfer
e. Steam output.

A

d. Heat transfer

63
Q

the water level falls too low during operation of a steam heating boiler, the operator should:

a. Tell his or her supervisor
b. Add more water immediately
c. Lower the flame and add water to bring it up to a safe level
d. Shut the boiler down
e. Operate the safety valve

A

d. Shut the boiler down

64
Q

An operating control switch for an ON-OFF boiler:

a. Uses a differential spring to reduce cycling
b. Can only have its cut-in setting adjusted
c. Has an un-adjustable span between cut-in and cut-out
d. Utilizes a resistance coil
e. Operates in conjunction with a Modutrol motor.

A

a. Uses a differential spring to reduce cycling

65
Q

In a two element feed water control, the following items are measured:

a. Boiler water level and steam flow
b. Feed water flow and steam flow
c. Boiler water level and feed water flow
d. Boiler water level and fuel flow
e. Temperature and volume of feed water

A

a. Boiler water level and steam flow

66
Q

Five common mediums used to implement process control includes, mechanical, pneumatic, electrical, analog and:

a. Liquid
b. Solid
c. Hydraulic
d. Digital
e. Fiber optics

A

d. Digital

67
Q

Boiler fuel should be shut off immediately if it fails to ignite to:

a. Save fuel
b. Prevent furnace explosions
c. Prevent spills
d. Save power
e. Prevent boiler corrosion.

A

d. Save power

68
Q

Pneumatic controllers are divided into two basic classes:

a. Direct and indirect
b. Off/on and proportional
c. Positive and negative action
d. Bleed and non-bleed
e. Reset and gain

A

d. Bleed and non-bleed

69
Q

An example of a controlled device would be a:

a. Damper motor operating air louvers
b. Hot water boiler
c. Radiator
d. Steam boiler
e. Thermostat.

A

a. Damper motor operating air louvers

70
Q

In the past the most popular method used to provide ventilation in a residence or small building has been by:

a. Mechanical ventilation
b. Natural ventilation
c. Electrical ventilation
d. Maximum air flow system
e. Minimum air flow system.

A

b. Natural ventilation

71
Q

When too much air has been absorbed by water in the expansion tank of a closed, system the tank must be:

a. Repaired
b. Filled
c. Removed
d. Drained
e. Enlarged

A

d. Drained

72
Q

An electronic controller is:

a. Not part of the electronic control system
b. Used to position an actuator
c. Used to generate a set point
d. A type of sensor
e. Used only in pneumatic systems.

A

b. Used to position an actuator

73
Q

Most dimmer switches sold today:

a. Can be used with incandescent or florescent lighting
b. Divert some current through a variable resistor
c. Can control the lighting level from 0 to 100%
d. Save most of the power not being used by the luminaire
e. Are not cost effective as energy savers.

A

d. Save most of the power not being used by the luminaire

74
Q

The function of the condenser is to:

a. Vaporize the liquid refrigerant
b. Change high, pressure refrigerant vapor to liquid
c. Pressurize low, pressure refrigerant vapor
d. Vent off vaporized refrigerant
e. Lower the liquid refrigerant pressure.

A

b. Change high, pressure refrigerant vapor to liquid

75
Q

In high efficiency furnaces, if the temperature of the flue gas drops below 65°C, the:

a. Flue gas will condense
b. Water vapor will condense
c. Furnace burner will shut down
d. Furnace burner will start up
e. Furnace vent will close

A

b. Water vapor will condense

76
Q

Ammonia refrigerants:

a. Have high sensible heat capacity
b. Mix well with oil
c. Are very expensive
d. Are well suited for industrial refrigeration
e. Are ideally suited to copper piping systems.

A

d. Are well suited for industrial refrigeration

77
Q

Plugged _____ on warm air heating and ventilating systems limit the air, flow and result in insufficient heating and a waste of fuel.

a. Filters
b. Drain lines
c. Diverters
d. Univents
e. Convectors.

A

a. Filters

78
Q

A purpose of a liquid refrigerant control or regulating valve is to:

a. Drain the receiver
b. Regulate the refrigerant flow to the condenser
c. Maintain a constant level in the receiver
d. Regulate the cooling water to the condenser
e. Isolate the high side from the low side

A

e. Isolate the high side from the low side

79
Q

The amount of water used in an evaporative condenser is only a small percentage of that used in a water condenser of the same capacity. This is due primarily to what?

a. Evaporating condensers also use air to cool the refrigerant
b. The evaporating condensers spray refrigerated water onto condensing coil
c. Water evaporating requires a large amount of latent heat
d. Water being recirculated
e. None of the above.

A

c. Water evaporating requires a large amount of latent heat

80
Q

The space around a magnet, through which the invisible magnetic lines of force are considered to travel, is known as the:

a. Flux field
b. Clearance space
c. Magnetic field
d. Planetary field
e. Charged field

A

c. Magnetic field

81
Q

The pounding or banging of pipes and shuddering of fixtures caused by a shock wave resulting from a sudden stop of water flow in a pipe is caused by:

a. Chattering of faucets
b. Whistling of faucets
c. Water hammer
d. Hissing of pipes
e. Creaking of pipes

A

c. Water hammer

82
Q

Pressure limiting devices shall be provided on all systems operating above atmospheric pressure, except on a factory sealed system containing less than _____ of group A1 refrigerant:

a. 9 kg
b. 7 kg
c. 10 kg
d. 5 kg
e. 3 kg.

A

c. 10 kg

83
Q

The purpose of the pipe siphon installed between the boiler and the pressure gauge is to prevent:

a. Air from entering the gauge
b. Water from entering the gauge
c. Hot steam from entering the gauge
d. Air from entering the boiler
e. Hot steam from entering the boiler.

A

c. Hot steam from entering the gauge

84
Q

The feedwater pipe before entering the boiler must contain:

a. A check valve with a stop valve between the check valve and the boiler
b. A check valve between the stop valve and the boiler c. A stop valve only
d. Two stop valves
e. A quick and slow opening stop valve.

A

a. A check valve with a stop valve between the check valve and the boiler

85
Q

Before commencing to operate a new plant, or one in which piping alterations have been made, the refrigerant system must be tested for:

a. High pressure
b. Vacuum control
c. Excessive oil consumption
d. Excessive vibration
e. Leaks

A

e. Leaks

86
Q

The simple control which restricts the flow of liquid from the condenser to the evaporator and maintains a pressure difference between the two units by using a considerable pressure drop resulting from resistance between the device’s length and small bore is called:

a. A high-pressure float valve
b. A low-pressure float valve
c. A bypass line
d. A capillary tube
e. An external float chamber.

A

d. A capillary tube

87
Q

A feedwater make-up system should:

a. Be able to satisfy the needs of at least one boiler in a multiboiler plant.
b. Utilize a deaerator.
c. Be able to satisfy normal firing needs.
d. Always be softened water.
e. Utilize demineralizers

A

c. Be able to satisfy normal firing needs.

88
Q

Which of the following statements about refrigeration pressure gages is true?

a. They indicate pressures and corresponding temperatures in a system.
b. Dials on refrigeration pressure gages do not indicate saturation temperature
c. Only one pressure gage is required for each system d. Pressure gage will not work if the system is equipped with pulsation dampeners
e. None of the above.

A

a. They indicate pressures and corresponding temperatures in a system.

89
Q

Should the steam line or water line to a gauge glass become plugged with sludge the gauge glass:

a. Level will drop in both cases
b. Level will drop in the first case and rise in the second c. Level will rise in the first case and drop in the second
d. Will read high
e. Level will remain where it was

A

d. Will read high

90
Q

What can cause a high discharge pressure in a refrigeration system?

a. Low evaporator level
b. Too much cooling water to the condenser
c. Over purging the unit
d. When the unit runs continuously
e. Unit is over charged with refrigerant

A

e. Unit is over charged with refrigerant

91
Q

Wet-bulb temperature is:

a. The temperature indicated by a thermometer having it’s bulb covered by a water-wetted wick or cloth and the bulb is exposed to a rapidly moving stream of air.
b. The same as the dry-bulb temperature if the relative humidity is less than 100%.
c. The dew point temperature.
d. Always less than the dry-bulb temperature.
e. Not required to find the relative humidity.

A

a. The temperature indicated by a thermometer having it’s bulb covered by a water-wetted wick or cloth and the bulb is exposed to a rapidly moving stream of air.

92
Q

If there is crystallization upon shutdown a possible corrective action?

a. Add octyl alcohol charge
b. Purge the system
c. Adjust cooling tower control
d. Check pump operation
e. Reduce steam pressure.

A

d. Check pump operation

93
Q

Classifications of air conditioning ducts include:

a. Low pressure and medium pressure.
b. Low pressure, medium pressure, and high pressure. c. Medium pressure and high pressure.
d. Absorption and compression.
e. Heating and cooling

A

b. Low pressure, medium pressure, and high pressure.

94
Q

The difference between the wet and dry bulb readings is called the:

a. Wet bulb depression.
b. Relative humidity.
c. Dew point.
d. Correction factor.
e. Dry bulb depression

A

a. Wet bulb depression.

95
Q

Ducts are fabricated of:

a. Sheet metal.
b. Cement asbestos.
c. Plastic.
d. Fiberglass.
e. All of the above

A

e. All of the above

96
Q

The purpose of the “freeze-stat” temperature controller used with hot water coils is to:

a. Close the outside air dampers and stop the fan if the heat source fails or the low limit temperature controller malfunctions.
b. Increase the hot water flow through the coil if outside air temperature is too low.
c. Increase the heat source temperature if the outside air temperature decreases.
d. Open the outside air dampers wide when the outside air temperature rises.
e. Increase the fan output if the return air temperature is too low

A

a. Close the outside air dampers and stop the fan if the heat source fails or the low limit temperature controller malfunctions.

97
Q

The flow arrangement best suited for hot water coils used to heat sub-freezing air is:

a. The counter flow arrangement because it is more efficient.
b. The parallel flow arrangement because it gives better protection against freezing.
c. One in which the cold air enters the coil where the coldest water is flowing.
d. The half serpentine.
e. The triple bypass flow arrangement.

A

b. The parallel flow arrangement because it gives better protection against freezing.

98
Q

To offset the heat gain through the building’s exterior shell from solar radiation, the atmosphere surrounding the building and from internal sources of heat what is required?

a. A humidifier.
b. A heat source.
c. Ventilation.
d. A cooling source.
e. A dehumidifier.

A

d. A cooling source.

99
Q

Using the psychrometric chart, find the dew point temperature at a dry bulb temperature of 25° C and a wet bulb temperature of 20° C.

a. 17.5°C
b. 14°C
c. 20°C
d. 16°C
e. 19°C.

A

a. 17.5°C

100
Q

Shock effect is:

a. A constant dry bulb temperature of 25° C.
b. A constant effective temperature of 15° C.
c. The discomfort felt when a person moves from a much hotter space to a much cooler place or vice versa.
d. More apparent in the winter.
e. A constant wet bulb temperature of 25° C

A

c. The discomfort felt when a person moves from a much hotter space to a much cooler place or vice versa.

101
Q

A system that provides cooling and heating all year round is highly energy efficient but has a high initial cost. The system consists of two separate supply and return piping systems that are connected to separate coils. Which of the following systems fits the above description?

a. A single pipe system.
b. A four pipe system.
c. A Hydronic heat pump system.
d. A three pipe system.
e. A two pipe system.

A

b. A four pipe system.

102
Q

Air used for ventilating purposes in an office building should be kept within a certain range of relative humidity as indicated below:

a. 30 to 50%
b. 30 to 70%
c. 40 to 50%
d. 50 to 60%
e. 10 to 30%

A

b. 30 to 70%

103
Q

Taper, plug and bottoming are types of:

a. Wrenches.
b. Dies.
c. Files.
d. Punches.
e. Taps.

A

e. Taps.

104
Q

Static pressure exerted by air is measured by connecting a:

a. Manometer at right angles to the air duct.
b. Bourdon tube pressure gage to the air duct.
c. Pressure gage with the opening with the opening facing air, flow.
d. Manometer with the opening facing the air, flow.
e. Manometer to the fan.

A

a. Manometer at right angles to the air duct.

105
Q

Air ventilation is based on the larger of these two requirements:

a. Solar heat rate and CFM rate per person.
b. Conduction rate per person and solar heat rate.
c. CFM rate and conduction rate per person.
d. Infiltration rate and CFM rate per person.
e. None of the above.

A

d. Infiltration rate and CFM rate per person.

106
Q

Air washers used in air conditioning systems:

a. Only clean the air.
b. Only clean and cool the air.
c. Only humidify and dehumidify the air.
d. Humidify, heat, cool, dehumidify, and clean the air.
e. Only humidify, cool and clean the air.

A

d. Humidify, heat, cool, dehumidify, and clean the air

107
Q

A factor limiting the number of fins that can be used on coils is the:

a. Diameter of the tube.
b. Temperature of the fluid in the tube.
c. Material that the tube is made of.
d. Resistance to airflow.
e. Direction the fluid is flowing in the tube

A

d. Resistance to airflow.

108
Q

The vane axial flow fan:

a. Has a more spiral air, flow than the tube axial fan.
b. Has more turbulent air, flow than the tube axial fan.
c. Has lower efficiency than the tube axial fan.
d. Has less spiral air, flow, less friction, and better efficiency than the tube axial fan.
e. Is not suitable for duct mounting.

A

d. Has less spiral air, flow, less friction, and better efficiency than the tube axial fan

109
Q

Lock washers:

a. Prevent marring of the work surface.
b. Distribute the lock nut force.
c. Allow oversized bolts or nuts to be used.
d. Prevent unwanted turning of the bolt or nut.
e. Prevent anyone from dismantling the object

A

d. Prevent unwanted turning of the bolt or nut.

110
Q

A tube beading tool is used:

a. On water tube boilers.
b. On fire tube boilers.
c. To fasten the stays in the tube sheet.
d. To cut fire tubes.
. To unfasten fire tubes from the tube sheet

A

b. On fire tube boilers.

111
Q

Coking of hot oil in heater tubes would begin to take place at:

a. 150°C.
b. 200°C.
c. 260°C.
d. 275°C.
e. 350°C

A

c. 260°C.

112
Q

In severely cold weather what adjustment must be made to properly preheat the outside air?

a. The temperature controller’s throttling range must be increased.
b. The outdoor damper should be closed.
c. Two separate pre-heater coils should be installed.
d. Damper must be heated.
e. Preheat coil temperature should be increased.

A

c. Two separate pre-heater coils should be installed.

113
Q

Hydrocarbons in a natural gas may include:

a. Carbon dioxide.
b. Ethane.
c. Nitrogen.
d. Hydrogen sulphide.
e. Carbonic acid.

A

b. Ethane.

114
Q

A natural gas sweetening unit in an oil refinery uses:

a. Heat only to drive off the hydrogen sulphide from the sour gas.
b. An amine contactor to absorb the hydrogen sulphide from the sour gas.
c. An amine contactor to absorb the hydrogen sulphide from the crude oil.
d. Amine solution to absorb the hydrogen sulphide from the gasoline.
e. Hear only to drive off the hydrogen sulphide from the crude oil.

A

b. An amine contactor to absorb the hydrogen sulphide from the sour gas.

115
Q

If possible, you should not work any higher than _____ steps from the top of a ladder.

a. Three.
b. Two.
c. One.
d. Four.
e. Five

A

a. Three.

116
Q

A low hot oil flow shutdown (FSDL) _____ installed in the outlet line of an oil heater.

a. Is almost always.
b. Is always.
c. Is sometimes.
d. Is never.
e. Cannot be.

A

b. Is always.

117
Q

Overheated oil in fired heater’s tubes breaks down to form:

a. Ash.
b. Paraffin.
c. Clinkers.
d. Coke.
e. Carbonic acid

A

d. Coke.

118
Q

The most important piece of equipment of a hot oil system is the:

a. Heater.
b. Pump.
c. Surge tank.
d. UV scanner.
e. Burner

A

a. Heater.

119
Q

A high flash point in oil reduces the risk of:

a. Pump cavitation.
b. Condensation.
c. Vapor bubble formation.
d. Heat transfer.
e. Fire.

A

e. Fire.

120
Q

To avoid start-up difficulties in cold weather a thermal fluid must have:

a. A low pour point.
b. Antifreeze added to it.
c. Methanol injected into it periodically.
d. A dehydration system installed in the surge tank.
e. A low fire point.

A

a. A low pour point.

121
Q

The purpose of “cooking” in a pulp mill is to:

a. Soften the wood chips.
b. Remove the lignin from the wood chips.
c. Heat the wood chips.
d. Remove the fiber from the wood chips.
e. Remove the bark from the logs

A

b. Remove the lignin from the wood chips.

122
Q

The air in a hot water heating system removed by the air separator is vented to the:

a. Air space at the top of the boiler
b. Nearest convector
c. Dip tube
d. Expansion tank
e. Relief valve.

A

d. Expansion tank

123
Q

A high pressure pump is the:

  1. Volute
  2. Diffuser
  3. Centrifugal
  4. Regenerative
  5. Diaphragm.

a. 1, 2 b. 1, 3 c. 2, 4 d. 3, 5 e. 4, 5.

A

e. 4, 5.

124
Q

Liquid must be in its vapor form:

a. In order to measure density
b. If purity is to be measured
c. When a chromatograph is being used
d. When conductivity is measured
e. When resistance or reluctance is being measured.

A

c. When a chromatograph is being used

125
Q

A hydrostatic test should be applied to a boiler:

a. At the request of the boiler inspector.
b. Once per year.
c. Once per week.
d. Every shift.
e. At the request of the owner

A

a. At the request of the boiler inspector.

FINAL PWEN ABSA PRACTICE 3 (1 decks)

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