Book 1 Chapter 11: Basic Boiler Operation

Question 1

A hot water heating system automatic fill valve will:
A) sense expansion tank level
B) maintain system pressure, regardless of level
C) maintain boiler water level at some predetermined value
D) prevent the boiler from tripping on low water level

Answer 1

B) maintain system pressure, regardless of level

Question 2

Prior to starting a new boiler for the first time, it is common practice to:
A) establish a main flame first to ensure the controls function properly
B) ensure all controls work before contacting an inspector
C) “boil out” the waterside with chemicals to remove oil, etc.
D) test the safety or relief valve first

Answer 2

C) “boil out” the waterside with chemicals to remove oil, etc

Question 3

Boiler stack temperature is rising due to soot build-up on the boiler tubes. This could:
A) result in condensation forming in the flue gas system
B) cause the water level to drop to the trip level
C) cause foaming of the boiler water
D) cause a furnace explosion

Answer 3

D) cause a furnace explosion

Question 4

When doing routine checks on a hot water system, one thing that is often overlooked is:
A) system pressure
B) expansion tank level
C) unusual noises
D) fuel pressure

Answer 4

C) unusual noises

Question 5

Two conditions that may occur during warm-up of a cold boiler are smoking and:
A) fuel flow surging
B) flame pulsations
C) very high stack temperatures
D) flue gas condensation

Answer 5

D) flue gas condensation

Question 6

A boiler item that should be checked monthly is:
A) refractory
B) fireside cleanliness
C) the flame detection system
D) water outlet temperature

Answer 6

C) the flame detection system

Question 7

If maintenance is planned for a hot water boiler, it should be drained:
A) only after it has cooled down
B) as soon as possible after removal from service
C) with the vent valve closed
D) while using cold feedwater to cool it

Answer 7

A) only after it has cooled down

Question 8

A hot water boiler should be equipped with water supply and return valves so that:
A) it can be drained without draining the system
B) it cannot be isolated from the system
C) the system can be drained through the boiler
D) boiler pressure will not be applied to the system

Answer 8

A) it can be drained without draining the system

Question 9

During the filling of an empty boiler, a valve that should be open to allow the air to escape is the:
A) gauge glass steam valve
B) boiler drain valve
C) boiler vent valve
D) gauge glass drain valve

Answer 9

C) boiler vent valve

Question 10

Which of the following is done to prevent excessive stresses of boiler metal due to enfeebled expansion?
A) warm a boiler up as quickly as possible
B) open the safety valve slowly during a test
C) warm the boiler up before filling it with water
D) warm the boiler up as slowly as possible

Answer 10

D) warm the boiler up as slowly as possible

Question 11

If boiler water level has dropped below the gauge glass during boiler operation, the operator is to:
A) contact the boiler inspector immediately
B) shut down, cool, and then inspect the boiler for damage before refilling
C) immediately restore water level before shutting off the unit
D) open the blowdown valves in order to have the low water fuel cut-off trip the unit

Answer 11

B) shut down, cool, and then inspect the boiler for damage before refilling

Question 12

Some of the reasons why heating boiler accidents occur are:
A) the misconception that no supervision is required for automatically-fired boilers
B) the inexperience or lack of training of operating personnel
C) inadequate maintenance of boilers and controls
D) all of the above

Answer 12

D) all of the above

Question 13

The most important factor to be considered during steam boiler operation is:
A) housekeeping
B) water level
C) steam pressure
D) combustion quality

Answer 13

B) water level

Question 14

When removing a steam boiler from service, the vent valve should be opened at 15-20kPa to:
A) permit draining of the boiler while it is still hot
B) let the O2 within the boiler escape
C) maintain the boiler water level at operating level
D) prevent a vacuum from forming in the boiler

Answer 14

D) prevent a vacuum from forming in the boiler

Question 15

Which of the following is not a possible cause of the damper motor failing to operate?
A) High-low fire or modulating control set improperly
B) Loss of fluid in the motor float chamber
C) Positioning switch in wrong position
D) Motor contacts malfunctioning
E) A loose or jammed linkage

Answer 15

B) Loss of fluid in the motor float chamber

Question 16

The operating pressure control will control the:
A) Boiler furnace pressure
B) Steam pressure in the boiler
C) Gas pressure to the burner
D) Water pressure to the boiler
E) Steam pressure in the steam header

Answer 16

B) Steam pressure in the boiler

Question 17

Automatic boiler programming controls may use:
A) All answers shown
B) Interlocking devices
C) A modulating control system
D) An on-off or two-position control switch
E) High-low fire control

Answer 17

A) All answers shown

Question 18

To meet the programmed control startup conditions, the automatic boiler liquid fuel manual valves should be opened:
A) Immediately after completion of the pilot flame trial
B) With the automatic main burner fuel valve
C) After pre-purge and just prior to pilot ignition
D) Prior to pre-purging
E) After the automatic main burner fuel valve opens

Answer 18

D) Prior to pre-purging

Question 19

When the safety devices and limit controls on boilers, are activated, they shut off the:
A) Flue gas flow
B) Fuel flow
C) Feedwater flow
D) Combustion air flow
E) Steam flow

Answer 19

B) Fuel flow

Question 20

If pilot ignition has not taken place, the oil fired boiler:
A) Will attempt restart after reset and the lock out switch has cooled down
B) Does not need to be purged again
C) Will be able to be restarted immediately
D) Will start after reset
E) Will restart when low airflow switch is closed

Answer 20

A) Will attempt restart after reset and the lock out switch has cooled down

Question 21

On a gas fired automatic boiler a normal programmed start-up takes approximately:
A) 55 seconds
B) 27-40 seconds
C) 120 seconds
D) 70 seconds
E) 105 seconds

Answer 21

E) 105 seconds

Question 22

Boiler furnace are purged:
A) To allow any hot refractory to completely cool
B) So that combustibles are fully removed prior to ignition
C) So that the operator can check the fuel and water systems
D) So that the programmer has time to verify permissiveness of interlocks
E) In order to allow combustion gases to accumulate prior to ignition

Answer 22

B) So that combustibles are fully removed prior to ignition

Question 23

In the following start up and shut down sequence for gas fired boilers, which steps are out of order?
1. Starting switch closed. Operating control in cut in position. Master relay energized. Timer starts. Fan starts. Programmer takes control of damper motor. Purge initiated at maximum airflow.
2. Low airflow switch closed
3. Damper placed in low fire position for purge at reduced flow. Low fire switch must close for ignition to take place
4. Flame relay switch is open
5. End of purge period. Ignition energized. Pilot gas valve opens. Start of trial period. When scanner senses pilot flame, the flame relay closes
6. Main gas valve is energized, main burner lights. Start of main burner ignition
7. Pilot valve and ignition de-energized. Programmer releases control of damper motor. Damper and fuel valve are now placed in high fire position by the modulating operating control if the boiler is on automatic control, or they are placed on the demand setting of the firing rate selector switch if the boiler is on manual control
8. End of start cycle, beginning of normal firing period. Timer motor stops, burner and blower remain in operation until heat demand is satisfied and operating controls reach their cut-out points.
9. Operating control opens. Master relay and fuel valve de-energize. Scanner ceases to sense flame. Flame relay opens. Timer restarts. Programmer takes control of modulating motor and holds it in low fire position. Start of after-purge period at low air flow.
10. End of after-purge period. Blower motor stops, timer stops. The system is now ready again for a restart whenever operation control reaches its cut-in point.

A) 5&6
B) None are out of order
C) 8&9
D)1&2
E)10&5

Answer 23

B) None are out of order

Question 24

During the startup of an oil fired boiler at the end of the purge the timer:
A) Shuts down
B) Goes through an ignition trial
C) Energizes the ignition transformer
D) Opens the pilot valve
E) Opens the fuel valve

Answer 24

C) Energizes the ignition transformer

Question 25

For programmed startup of boilers with Natural Draft the electrical circuit to the main gas valve is closed:
A) During pilot ignition
B) When the flame detector senses the pilot flame
C) While purging
D) Before purging
E) When the water level is high

Answer 25

B) When the flame detector senses the pilot flame

Question 26

Which of the following is not required before starting using programming control?
A) Main gas valve closed
B) Gas pressure above low pressure cutoff
C) Main power on
D) Water temp below cut in
E) Water level above cutoff

Answer 26

A) Main gas valve closed

Question 27

Some of the reasons why heating boiler accidents occur are:
A) Failure to test the low water fuel cutoff
B) The misconception that no supervision is required for automatically-fired boilers
C) Inadequate maintenance of boilers and controls
D) All of the above
E) The inexperience or lack of training of operating personnel

Answer 27

D) All of the above

Question 28

If boiler water level has dropped below the gauge glass during boiler operation, the operator is to:
A) Open the blowdown valves in order to have the low water fuel cut-off trip the unit
B) Immediately restore water level before shutting off the unit
C) Contact the boiler inspector immediately
D) Slowly reduce the boiler load
E) Shut down, cool, and then inspect the boiler for damage before refilling

Answer 28

E) Shut down, cool, and then inspect the boiler for damage before refilling

Question 29

Should the boilers blower or fan fail the supply of combustion air will cease and the ____ cut-off switch will cut off the power to the fuel valve as soon as the pressure at the blower discharge drops below the minimum safe value.
A) Low fuel
B) Flame scanner
C) Low water
D) Low air
E) High air

Answer 29

D) Low air

Question 30

Flame failure may occur during operation due to;
A) Air in the fuel
B) Excessively high fuel pressure
C) High boiler load
D) Insufficient fuel oil supply due to plugged filter
E) Overly high gas pressure

Answer 30

D) Insufficient fuel oil supply due to plugged filter

Question 31

Boiler priming occurs as a result of;
A) A chemical problem within the boiler
B) A mechanical malfunction
C) The low steam production
D) A low water condition
E) The loss of flame in the furnace

Answer 31

B) A mechanical malfunction

Question 32

When removing a hot water boiler from service open the blow-off or drain valve on the bottom of the boiler to remove any sediment that may have collected stopping when the:
A) Low water level alarm sounds
B) Boiler is empty
C) Low water fuel cutoff activates
D) Water runs clear
E) Water level drops below the gauge glass

Answer 32

D) Water runs clear

Question 33

Should the water in the gauge glass of a steam boiler, show a higher than normal level or even climb out of sight the level should be brought back to normal to prevent:
A) Producing wet steam
B) The boiler water from foaming
C) A pressure component failure
D) A decrease in steam production
E) Carry-over of the water with the steam

Answer 33

E) Carry-over of the water with the steam

Question 34

When a steam boiler has to be taken out of service give it a good blowdown to remove as much sediment as possible stop when the drain runs clear. Refill the boiler to the top of the glass maintaining the boiler water temperature above _____ for about an hour to release all the dissolved gases.
A) 120C (248F)
B) 77C (170F)
C) 85C (185F)
D) 121C (250F
E) 50C (98F)

Answer 34

C) 85C (185F)

Question 35

Boiler stack temperature is rising due to soot build up on the boiler tubes. This could:
A) Result in condensation forming in the flue gas system
B) Cause foaming of the boiler water
C) Cause the water level to drop to the trip level
D) Cause a furnace explosion
E) Result in a pressure explosion

Answer 35

D) Cause a furnace explosion

Question 36

The most important rule in the safe operation of steam boilers is to:
A) Blowdown the gauge glass regularly
B) Keep the feedwater chemical free
C) Add chemicals to the boiler feedwater
D) Keep the boiler pressure below the safety valve setting
E) Keep water in the boiler at the proper level

Answer 36

E) Keep water in the boiler at the proper level