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Flashcards in Steam Boilers Tech Check 8 Deck (23)
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1
Q

The primary function of a combustion control is to ensure———–

A safe boiler operation
B. boiler efficiency
C.safe and efficient boiler operation
D temperature regulation of the gases of combustion

A

C.safe and efficient boiler operation

2
Q

The ON/OFF control system is usually found on————

A. boilers with large fluctuating loads
B. package fire tube boilers
C. boilers with high steam demand but constant load
D. low pressure boilers only

A

B. package fire tube boilers

3
Q

The purpose of the boiler pressure control found in the ON/oFF control system is to————–

A regulate steam flow
B. regulate air flow
C. regulate fuel flow
D. start and stop the burner on steam pressure demand

A

D. start and stop the burner on steam pressure demand

4
Q

The ON/OFF pressure control must be connected to the————

A.main steam line
B. main feedwater line
C. highest part of the steam side of the boiler
D. water side of the boiler below the NOWL

A

C. highest part of the steam side of the boiler

5
Q

A steam siphon ensures that———– does not enter the boiler pressure control.

A steam
B. water
C. air
D.gas

A

A steam

6
Q

A mercury-tube pressure control will only be accurate when it is installed

A. at the NOWL
B. below the NOWL
C. in a vertical position
D. in a horizontal position

A

C. in a vertical position

7
Q

four elements that must be regulated in a combustion control system are———-,———–,———–,and——–.

A. fuel supply air supply; ratio of air to fuel; removal of
combustion gases
B. fuel supply water supply; air supply; ratio of water to fuel
C. temperature of water; temperature of fuel; temperature of steam; temperature of exit gases
D. pressure of water; pressure of steam; pressure of fuel;pressure of air

A

A. fuel supply air supply; ratio of air to fuel; removal of

combustion gases

8
Q

The two scales found on the boiler pressure control are used to———-

A. set the operating steam pressure range of the boiler
B. eliminate low water
C. maintain high and low fire
D. warn the operator of flame failure

A

A. set the operating steam pressure range of the boiler

9
Q

The purpose of the boiler modulating pressure control is to———

A. regulate the water flow
B. prevent carryover
C. start and stop the burner on steam pressure demand
D. regulate the high and low firing rates of the burner

A

D. regulate the high and low firing rates of the burner

10
Q

The modulating pressure control must be connected to the————-

A. main steam line
B. main feedwater line
C. highest part of the steam side of the boiler
D water side of the boiler below the NowL

A

C. highest part of the steam side of the boiler

11
Q

The burner motor continues to operate after fuel is shut off to the burner during————-

A. post purging
B. pre purging
C. synchronization
D. ignition lightoff

A

C. synchronization

12
Q

The programmer in the ON/OFF control system is used to—————-

A. control the burner firing cycle
B. control the boiler operating range
C. secure the burner in the event of low water
D. regulate the steam flow

A

A. control the burner firing cycle

13
Q

To eliminate the danger of a furnace explosion during startup, the firing sequence must first allow for————

A. pilot ignition
B. proving the pilot
C. a prepurge period
D. proving the main flame

A

C. a prepurge period

14
Q

The purpose of the scanner is to prove

A, only the pilot
B. only the main flame
C. both the pilot and the main flame
D. the proper boiler water level

A

C. both the pilot and the main flame

15
Q

The scanner must be installed on the front of the boiler to sight————

A. both the pilot and the main flame
B. the pilot only
C. the main flame only
D. the boiler water level

A

A. both the pilot and the main flame

16
Q

The scanner is sensitive to————

A. heat
B. temperature
C. pressure
D. infrared or ultraviolet rays

A

D. infrared or ultraviolet rays

17
Q

In the event of a flame failure, the programmer will——-

A. go through a new firing cycle
B. secure the fuel, purge the firebox, and then shut down
C. vent the combustion chamber
D. start the induced draft fan

A

B. secure the fuel, purge the firebox, and then shut down

18
Q

The positioning combustion control system cannot function without———- pressure.

A. steam
B. water
C. air
D. gas

A

C. air

19
Q

The metering combustion control system is sensitive to changes in———–

A. boiler water level
B. firing rate
C. steam flow and pressure
D. viscosity of the fuel oil

A

C. steam flow and pressure

20
Q

Combustion air is controlled by————–

A. inlet dampers, fan vanes, and the fan speed
B. the outlet damper and fan speed
C. starting and stopping the forced draft fan
D. variations in control air pressure

A

A. inlet dampers, fan vanes, and the fan speed

21
Q

Gases of combustion are pulled from the boiler by the———-

A. forced draft fan
B. induced draft fan.
C. variable-speed motor
D. hydraulic couplings

A

B. induced draft fan.

22
Q

The positioning combustion control system is sensitive to changes in the———

A. boiler water level
B. firing rate
C. steam flow
D. steam header pressure

A

D. steam header pressure

23
Q

The most common type of pressure control used is the ——–type

A. mercury-tube
B. microswitch
C. pigtail
D. U-tube

A

A. mercury-tube