ABSA 5th Class UPDATED ACTUAL
Questions and CORRECT Answers
Where are the return openings located regarding air distribution systems? - CORRECT
ANSWER - Return air openings are located on inner walls.
The minimum temperature of the water used in a hydrostatic test of a boiler cannot be less than
what temperature? - CORRECT ANSWER - 20 degrees Celsius
Which of the following are causes of pressure explosions?
1. effects of corrosion
2. weak pilot flame
3. stressed material due to heating too quickly
4. insufficient purge
5. scale and sludge build-up - CORRECT ANSWER - 1, 3, 5
Carbon, which is not combined with hydrogen, is referred to as: - CORRECT ANSWER -
Fixed Carbon
Maximum static pressure in a fuel oil line is approximately: - CORRECT ANSWER - 35
kPa
Combustion of a fuel in a boiler furnace: - CORRECT ANSWER - should be performed
with a minimum of excess air
,What is a hydrostatic test? - CORRECT ANSWER - A way in which pressure vessels can
be tested for strength and leaks.
How often do burner and fan motors which uses standard bearing normally require lubrication? -
CORRECT ANSWER - Yearly
On a hot water boiler, the pressure differential between the operating pressure and the safety
relief valve set pressure must be (at a minimum):
1. 25% of operating pressure
2. 125% of operating pressure
3. 69 kPa
4. 25% of the safety relief valve set pressure - CORRECT ANSWER - 3, 4
In hot water boiler operation the maximum operating temperature should never exceed: -
CORRECT ANSWER - 121 degrees celsius
A substance, which will absorb humidity inside a boiler during dry lay up is: - CORRECT
ANSWER - Activated alumina
When draft is produced by natural means: - CORRECT ANSWER - cooler air
surrounding the boiler increases draft
,Coal is composed of the following combustible components: - CORRECT ANSWER -
Carbon, hydrogen, Sulphur
Which of the following are causes of furnace explosions?
1. main fuel valve closed when the burner flame is lost
2. insufficient purge
3. burners lit from hot refractory
4. effects of corrosion
5. admission of fuel before ignition source - CORRECT ANSWER - 3,4,5
Which grade of oil is the most popular for domestic and small commercial boilers? - CORRECT
ANSWER - Grade 2
The inclined manometer as compared to the U manometer is what? - CORRECT
ANSWER - More accurate.
How can the draft through a natural draft furnace be increased? - CORRECT ANSWER -
Increase the temperature of the stack
The main function of a gas burner is: - CORRECT ANSWER - provision of O2 - fuel
contact
The minimum distance from furnace to oil storage tank is: - CORRECT ANSWER - 2
feet
, One of the main component of an electric ignition system is the step-up transformer which takes
120 V and boosts it to _____ volts - CORRECT ANSWER - 10,000 - 12,000 volts.
Combustion of a fuel in a boiler furnace should be performed in what conditions? - CORRECT
ANSWER - There should be a minimum of excess air.
What type of oil burner is used when oil is supplied under high pressure? - CORRECT
ANSWER - Mechanical Atomizing Burner
An air atomizing compressor is usually what type? - CORRECT ANSWER - A rotary
type.
Which of the following advantages does oil have over coal as a boiler fuel?
1. requires less storage space
2. costs less to handle
3. fuel quantity is easier to control
4. burns more cleanly - CORRECT ANSWER - All of the above
In a boiler burner with 3 fixed capacity nozzles,the intermediate and high burner nozzles have
higher capacities than the primary burner nozzle for what reason? - CORRECT
ANSWER - To allow better boiler warm-ups
What is a manometer used for? - CORRECT ANSWER - Measure draft
A draft gauge on a furnace indicates the draft in: - CORRECT ANSWER - mm of water
column
A solenoid type fuel gas valve is held close by what? - CORRECT ANSWER - Fuel
pressure
Questions and CORRECT Answers
Where are the return openings located regarding air distribution systems? - CORRECT
ANSWER - Return air openings are located on inner walls.
The minimum temperature of the water used in a hydrostatic test of a boiler cannot be less than
what temperature? - CORRECT ANSWER - 20 degrees Celsius
Which of the following are causes of pressure explosions?
1. effects of corrosion
2. weak pilot flame
3. stressed material due to heating too quickly
4. insufficient purge
5. scale and sludge build-up - CORRECT ANSWER - 1, 3, 5
Carbon, which is not combined with hydrogen, is referred to as: - CORRECT ANSWER -
Fixed Carbon
Maximum static pressure in a fuel oil line is approximately: - CORRECT ANSWER - 35
kPa
Combustion of a fuel in a boiler furnace: - CORRECT ANSWER - should be performed
with a minimum of excess air
,What is a hydrostatic test? - CORRECT ANSWER - A way in which pressure vessels can
be tested for strength and leaks.
How often do burner and fan motors which uses standard bearing normally require lubrication? -
CORRECT ANSWER - Yearly
On a hot water boiler, the pressure differential between the operating pressure and the safety
relief valve set pressure must be (at a minimum):
1. 25% of operating pressure
2. 125% of operating pressure
3. 69 kPa
4. 25% of the safety relief valve set pressure - CORRECT ANSWER - 3, 4
In hot water boiler operation the maximum operating temperature should never exceed: -
CORRECT ANSWER - 121 degrees celsius
A substance, which will absorb humidity inside a boiler during dry lay up is: - CORRECT
ANSWER - Activated alumina
When draft is produced by natural means: - CORRECT ANSWER - cooler air
surrounding the boiler increases draft
,Coal is composed of the following combustible components: - CORRECT ANSWER -
Carbon, hydrogen, Sulphur
Which of the following are causes of furnace explosions?
1. main fuel valve closed when the burner flame is lost
2. insufficient purge
3. burners lit from hot refractory
4. effects of corrosion
5. admission of fuel before ignition source - CORRECT ANSWER - 3,4,5
Which grade of oil is the most popular for domestic and small commercial boilers? - CORRECT
ANSWER - Grade 2
The inclined manometer as compared to the U manometer is what? - CORRECT
ANSWER - More accurate.
How can the draft through a natural draft furnace be increased? - CORRECT ANSWER -
Increase the temperature of the stack
The main function of a gas burner is: - CORRECT ANSWER - provision of O2 - fuel
contact
The minimum distance from furnace to oil storage tank is: - CORRECT ANSWER - 2
feet
, One of the main component of an electric ignition system is the step-up transformer which takes
120 V and boosts it to _____ volts - CORRECT ANSWER - 10,000 - 12,000 volts.
Combustion of a fuel in a boiler furnace should be performed in what conditions? - CORRECT
ANSWER - There should be a minimum of excess air.
What type of oil burner is used when oil is supplied under high pressure? - CORRECT
ANSWER - Mechanical Atomizing Burner
An air atomizing compressor is usually what type? - CORRECT ANSWER - A rotary
type.
Which of the following advantages does oil have over coal as a boiler fuel?
1. requires less storage space
2. costs less to handle
3. fuel quantity is easier to control
4. burns more cleanly - CORRECT ANSWER - All of the above
In a boiler burner with 3 fixed capacity nozzles,the intermediate and high burner nozzles have
higher capacities than the primary burner nozzle for what reason? - CORRECT
ANSWER - To allow better boiler warm-ups
What is a manometer used for? - CORRECT ANSWER - Measure draft
A draft gauge on a furnace indicates the draft in: - CORRECT ANSWER - mm of water
column
A solenoid type fuel gas valve is held close by what? - CORRECT ANSWER - Fuel
pressure
