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Power Engineering 5th Class Book 1 > Book1: Unit 2 - Review: Chapter 5 - 10 > Flashcards

Book1: Unit 2 - Review: Chapter 5 - 10 Flashcards

1
Q

What is the device used to determine that the fan motor is working:
Select one:

A. Air flow switch

B. Motor contactor

C. Indicator light

D. Power amperage draw meter

E. Flame scanner

A

A. Air flow switch

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2
Q

The purpose of the gauge glass or water gauge is to show the _____ in the boiler.
Select one:

A. Water level

B. Temperature of the steam

C. Color of the water

D. Steam level

E. Pressure of the water

A

A. Water level

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3
Q

In a building heating system the condensate in the condensate receiver tank comes from the:
Select one:

A. Heating system

B. Make-up water supply

C. Economizer

D. Boiler feedwater

E. Deaerator

A

A. Heating system

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4
Q

Each automatically fired hot water boiler shall have a high limit temperature control that will shut off the fuel supply to the boiler to prevent the water from exceeding the maximum allowable temperature of:
Select one:

A. 150°C (302°F)

B. 75°C (167°F)

C. 100°C (212°F)

D. 200°C (392°F)

E. 120°C (248°F)

A

E. 120°C (248°F)

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5
Q

If the pilot flame fails, no power is generated by the thermocouple preventing the _____ from supplying fuel to the burner on boiler startup.
Select one:

A. Pilot fuel control valve

B. Air supply valve

C. Main fuel control valve

D. Main relay valve

E. Operating control

A

C. Main fuel control valve

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6
Q

Boiler gauge glasses will break while in service due to the:
Select one:

A. Difference in temperature between the water and steam

B. Strain due to gauge fittings being in line

C. Safety lifting due to over pressure

D. Draft of hot air hitting the glass

E. Thinning of the glass by the action of the steam

A

E. Thinning of the glass by the action of the steam

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7
Q

The low water level fuel cut-off will shut off the fuel to the heating boiler when the water level drops below:
Select one:

A. 25 mm (1 in.) above the bottom of the gauge glass

B. One half of the gauge glass

C. The lowest visible part of the gauge glass

D. The lowest permissible water level

E. 50 mm (2 in.) above the bottom of the gauge glass

A

C. The lowest visible part of the gauge glass

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8
Q

On a hot water boiler, the highest value on the graduated scale of the pressure gauge shall not be less than _____ times the pressure at which the pressure relief valve is set..
Select one:

A. 3.5

B. 2.5

C. 1.5

D. 2

E. 3

A

C. 1.5

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9
Q

The blowdown of a safety valve may be decreased by:
Select one:

A. Increasing the spring pressure

B. Raising the lifting lever

C. Decreasing the spring pressure

D. Raising the adjusting ring

E. Lowering the adjusting ring

A

E. Lowering the adjusting ring

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10
Q

When the main steam stop valves of heating boilers are over 51 mm (2 in.) it is recommended that _____ be used.
Select one:

A. Diaphragm operated valves

B. Solenoid operated valves

C. Globe valves

D. Gate valves

E. OS & Y valves with rising spindles

A

E. OS & Y valves with rising spindles

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11
Q

A heating boiler must have a permanently attached marker indicating:
Select one:

A. The maximum allowable working temperature

B. Highest permissible water level

C. Lowest permissible steam level

D. The maximum allowable working pressure

E. Lowest permissible water level

A

E. Lowest permissible water level

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12
Q

The two types of boiler combustion control include:
1. On-Off
2. Automatic
3. Modulating
4. Manual
Select one:

A. 2, 4

B. 3, 4

C. 2, 3

D. 1, 3

E. 1, 2

A

D. 1, 3

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13
Q

The high gas pressure cut-off switch can be tested by:
Select one:

A. Slowly raising the boiler pressure above the operating setpoint

B. Closing the main gas valve quickly

C. Slowly covering the air supply to the fan

D. Quickly closing the main burner shut-off valve

E. Slowly closing the main gas valve

A

D. Quickly closing the main burner shut-off valve

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14
Q

A thermocouple consists of two dissimilar wires welded together at one end to form a:
Select one:

A. Cold junction

B. Reference junction

C. Metering junction

D. Hot junction

E. Electric circuit

A

D. Hot junction

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15
Q

The boiler vent valve is used for the purpose of allowing:
Select one:

A. Air to escape while filling

B. Water to escape while filling

C. Steam to escape while filling

D. Air to escape while draining

E. Steam to enter while draining

A

A. Air to escape while filling

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16
Q

A flame rod uses the principle that a flame is capable of:
Select one:

A. Heating the rod

B. Conducting electricity

C. Supplying fuel to the burner

D. Holding the solenoid open

E. Holding the solenoid closed

A

B. Conducting electricity

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17
Q

Before a steam or hot water boiler can be started by a programming control, all but one of the following conditions must be fulfilled:
Select one:

A. The steam pressure or water temperature must be at or below the cut-in setting of the operating control

B. The main power switch or breaker must be closed

C. All manually operated valves in the fuel lines to the pilot and main burner must be closed

D. The water in the boiler drum must be above the cut-off point of the low-water fuel cut-off

E. If the boiler is gas-fired, the fuel supply pressure to the burner valves must be above the cutout point of the low gas pressure cut-off

A

C. All manually operated valves in the fuel lines to the pilot and main burner must be closed

18
Q

A programming control on a natural draft gas fires boiler operates in the following sequence.
1. The main burner is ignited
2. The flame detector senses the flame and causes the main gas valve to open
3. The ignition transformer and pilot gas valve are de-energized and closed, if an interrupted pilot is used
4. The operating control initiates a startup
5. The load relay energizes the ignition transformer and the pilot gas valve
Select one:

A. 5, 3, 2, 1, 4

B. 4, 5, 2, 1, 3

C. 2, 5, 1, 4, 3

D. 3, 2, 1, 5, 4

E. 1, 2, 3, 4, 5

A

B. 4, 5, 2, 1, 3

19
Q

Purging a furnace means forcing a flow of:
Select one:

A. Air through a furnace for a set period of time when the burner is not in operation.

B. Water through a furnace for a set period of time when the burner is in operation.

C. Fuel through a furnace for a set period of time when the burner is in operation.

D. Fuel through a furnace for a set period of time when the burner is not in operation.

E. Air through a furnace for a set period of time when the burner is in operation.

A

A. Air through a furnace for a set period of time when the burner is not in operation.

20
Q

All fitting markings shall be legible and must indicate the following minimum requirements.
1. National Pipe Size
2. Manufacturer’s name or trade mark
3. Vendors Identification
4. Service designation
5. Material designation
Select one:

A. 3, 4, 5

B. 2, 4, 5

C. 1, 3, 5

D. 1, 2, 3

E. 2, 3, 4

A

B. 2, 4, 5

21
Q

The flame rod method of sensing is often referred to as:
Select one:

A. Photoelectric scanning

B. Flame rectification

C. Ultraviolet detection

D. Infrared detection

E. The ionized particle principle

A

B. Flame rectification

22
Q

A pipe siphon is used on a boiler to:
Select one:

A. Maintain a water seal between the water and the Bourdon tube

B. Maintain a steam seal between the steam and the Bourdon tube

C. Maintain a water seal between the steam and the Bourdon tube

D. Remove water from the boiler drum

E. Add water to the Bourdon tube

A

C. Maintain a water seal between the steam and the Bourdon tube

23
Q

Before feedwater enters a boiler the feedwater pipe must be fitted with a:
Select one:

A. Check valve between the stop valve and the boiler

B. Ball valve between the check valve and the boiler

C. Globe valve between the check valve and the boiler

D. Stop valve between the check valve and the boiler

E. Gate valve between the check valve and the boiler

A

D. Stop valve between the check valve and the boiler

24
Q

A hydrostatic test is at a pressure of

Select one:

A. 1.5 times atmospheric

B. 1.5 times the maximum allowable working pressure

C. 1.5 times the bursting pressure

D. 1.5 times the operating pressure

A

B. 1.5 times the maximum allowable working pressure

25
Q

The operating handle of the valve to the pressure gage on a hot water boiler must be of the:
Select one:

A. A valve is not permitted in this location

B. Tee or lever handle design

C. Hand wheel type

D. Diaphragm type

E. Solenoid type

A

B. Tee or lever handle design

26
Q

Three of the four distinct methods of burner operation control for a steam boiler are:
1. On-Off control
2. Damping control
3. Modulating control
4. High Limit control
5. Multiple burner control
Select one:

A. 2, 3, 4

B. 1, 3, 4

C. 3, 4, 5

D. 1, 2, 3

E. 2, 3, 5

A

B. 1, 3, 4

27
Q

The voltage supply generated by the thermocouple is usually not more than:
Select one:

A. 0 millivolts

B. 15 millivolts

C. 50 millivolts

D. 30 millivolts

E. 100 millivolts

A

D. 30 millivolts

28
Q

If the pressure of the gas supplied to the burner increases beyond the maximum required for safe combustion the _____ switch will de-energize the fuel valve.
Select one:

A. Low water level

B. Low gas pressure

C. High limit

D. High gas pressure

E. Low air pressure

A

D. High gas pressure

29
Q

If the pilot burner fails to ignite, or if the pilot does go on, the gas burner fails to ignite a lockout switch will be energized after a short trial period of _____ seconds from the time of startup.
Select one:

A. 10 to 20

B. 5 to 10

C. 20 to 40

D. 30 to 50

E. 15 to 30

A

E. 15 to 30

30
Q

If for any reason, the burner should go out during normal operation, or the fuel should fail to ignite during startup:
Select one:

A. Increase the combustion air flow

B. No action is required

C. The air to the burner must be shut off immediately

D. The fuel to the burner must be shut off immediately

E. Increase the fuel flow

A

D. The fuel to the burner must be shut off immediately

31
Q

If the combustion control safety lock-out switch is tripped:
Select one:

A. Check the low air pressure switch

B. Reset safety lock-out switch

C. Close the blower switch

D. Refer to manufacturer’s manual

E. Replace motor

A

B. Reset safety lock-out switch

32
Q

The low gas pressure cut-off switch can be tested by:
Select one:

A. Quickly closing the main burner shut-off valve

B. Slowly raising the boiler pressure above the operating setpoint

C. Slowly covering the air supply to the fan

D. Slowly closing the main gas valve

E. Closing the main gas valve quickly

A

D. Slowly closing the main gas valve

33
Q

The On-Off method of steam heating boiler burner control uses the _____ as the sensed variable.
Select one:

A. Boiler steam temperature

B. Drum water level

C. Boiler steam flow

D. Boiler steam pressure

E. Feedwater pressure

A

D. Boiler steam pressure

34
Q

The relief valve on hot water boilers with a working pressure of up to 414 kPa (60 psi) should open with in a variation of _____ below or above the setpoint.
Select one:

A. 14%

B. 5%

C. 10 kPa (1.5 psi)

D. 20 kPa (3 psi)

E. 30 kPa (4.5 psi)

A

D. 20 kPa (3 psi)

35
Q

Make-up water for the heating system usually comes from the:
Select one:

A. Returning condensate

B. Boiler feedwater

C. City water supply

D. Boiler feedwater pump

E. Deaerator

A

C. City water supply

36
Q

If the pressure of the gas supplied to the burner drops below a minimum value the _____ switch will de-energize the fuel valve.
Select one:

A. High limit

B. Low water level

C. Low air pressure

D. High gas pressure

E. Low gas pressure

A

E. Low gas pressure

37
Q

The switch in the operating control of a steam boiler is closed by:
Select one:

A. Falling steam pressure

B. Rising steam pressure

C. Rising steam temperature

D. Falling water pressure

E. Falling steam temperature

A

A. Falling steam pressure

38
Q

Blowdown valves are installed to:
1. Remove any accumulation of sediment
2. Remove contaminated steam
3. Drain the boiler
4. Lower the concentration of dissolved impurities in the steam
5. Lower the concentration of dissolved impurities in the water
Select one:

A. 2, 4, 5

B. 1, 3, 5

C. 3, 4, 5

D. 2, 3, 4

E. 1, 2, 3

A

B. 1, 3, 5

39
Q

The switch in the operating control of a hot water boiler is opened by:
Select one:

A. Falling water temperature

B. Rising water pressure

C. Falling water pressure

D. Rising steam temperature

E. Rising water temperature

A

E. Rising water temperature

40
Q

The low air pressure cut-off switch can be tested by:
Select one:

A. Slowly covering the air supply to the fan

B. Quickly closing the main burner shut-off valve

C. Slowly closing the main gas valve

D. Slowly raising the boiler pressure above the operating setpoint

E. Closing the main gas valve quickly

A

A. Slowly covering the air supply to the fan

Power Engineering 5th Class Book 1 (25 decks)

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