ABSA 5TH CLASS TEST STUDY GUIDE| EXAM
2025/2026 WITH COMPLETE SOLUTION
NEWEST 100% PASS
1. Where are the return openings located regarding air distribution systems? AN
>> -
Return air openings are located on inner walls.
2. The minimum temperature of the water used in a hydrostatic test of a boiler
cannot be less than what temperature? ANS >> 20 degrees Celsius
3. 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 ANS >> 1, 3, 5
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, 4. Carbon, which is not combined with hydrogen, is referred to as ANS >> ANS >>
Fixed Carbon
5. Maximum static pressure in a fuel oil line is approximately ANS >> ANS >> 35 kPa
6. Combustion of a fuel in a boiler furnace ANS >> ANS >> should be performed with a minimum o
excess air
7. What is a hydrostatic test? ANS >> A way in which pressure vessels can be tested for strength and leak
8. How often do burner and fan motors which uses standard bearing normally
require lubrication? ANS >> Yearly
9. On a hot water boiler, the pressure differential between the operating pres-
sure and the safety relief valve set pressure must be (at a minimum) ANS >>
1. 25% of operating pressure
2. 125% of operating pressure
3. 69 kPa
4. 25% of the safety relief valve set pressure ANS >> 3, 4
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, 10. In hot water boiler operation the maximum operating temperature should
never exceed ANS >> ANS >> 121 degrees celsius
11. A substance, which will absorb humidity inside a boiler during dry lay up
is ANS >> ANS >> Activated alumina
12. When draft is produced by natural means ANS >> ANS >> cooler air surrounding the boiler
increases draft
13. Coal is composed of the following combustible components ANS >> ANS >>
Carbon, hydrogen, Sulphur
14. 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 ANS >> 3,4,5
15. Which grade of oil is the most popular for domestic and small commercial
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, boilers? ANS >> Grade 2
16. The inclined manometer as compared to the U manometer is what? ANS >>
More accurate.
17. How can the draft through a natural draft furnace be increased? ANS >>
Increase the temperature of the stack
18. The main function of a gas burner is ANS >> ANS >> provision of O2 - fuel contact
19. The minimum distance from furnace to oil storage tank is ANS >> ANS >> 2 feet
20. One of the main component of an electric ignition system is the step-up
transformer which takes 120 V and boosts it to volts ANS >> 10,000 - 12,000
volts.
21. Combustion of a fuel in a boiler furnace should be performed in what
conditions? ANS >> There should be a minimum of excess air.
22. What type of oil burner is used when oil is supplied under high pressure? ANS
>> -
Mechanical Atomizing Burner
23. An air atomizing compressor is usually what type? ANS >> A rotary type.
https://www.stuvia.com/user/Mboffin
2025/2026 WITH COMPLETE SOLUTION
NEWEST 100% PASS
1. Where are the return openings located regarding air distribution systems? AN
>> -
Return air openings are located on inner walls.
2. The minimum temperature of the water used in a hydrostatic test of a boiler
cannot be less than what temperature? ANS >> 20 degrees Celsius
3. 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 ANS >> 1, 3, 5
https://www.stuvia.com/user/Mboffin
, 4. Carbon, which is not combined with hydrogen, is referred to as ANS >> ANS >>
Fixed Carbon
5. Maximum static pressure in a fuel oil line is approximately ANS >> ANS >> 35 kPa
6. Combustion of a fuel in a boiler furnace ANS >> ANS >> should be performed with a minimum o
excess air
7. What is a hydrostatic test? ANS >> A way in which pressure vessels can be tested for strength and leak
8. How often do burner and fan motors which uses standard bearing normally
require lubrication? ANS >> Yearly
9. On a hot water boiler, the pressure differential between the operating pres-
sure and the safety relief valve set pressure must be (at a minimum) ANS >>
1. 25% of operating pressure
2. 125% of operating pressure
3. 69 kPa
4. 25% of the safety relief valve set pressure ANS >> 3, 4
https://www.stuvia.com/user/Mboffin
, 10. In hot water boiler operation the maximum operating temperature should
never exceed ANS >> ANS >> 121 degrees celsius
11. A substance, which will absorb humidity inside a boiler during dry lay up
is ANS >> ANS >> Activated alumina
12. When draft is produced by natural means ANS >> ANS >> cooler air surrounding the boiler
increases draft
13. Coal is composed of the following combustible components ANS >> ANS >>
Carbon, hydrogen, Sulphur
14. 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 ANS >> 3,4,5
15. Which grade of oil is the most popular for domestic and small commercial
https://www.stuvia.com/user/Mboffin
, boilers? ANS >> Grade 2
16. The inclined manometer as compared to the U manometer is what? ANS >>
More accurate.
17. How can the draft through a natural draft furnace be increased? ANS >>
Increase the temperature of the stack
18. The main function of a gas burner is ANS >> ANS >> provision of O2 - fuel contact
19. The minimum distance from furnace to oil storage tank is ANS >> ANS >> 2 feet
20. One of the main component of an electric ignition system is the step-up
transformer which takes 120 V and boosts it to volts ANS >> 10,000 - 12,000
volts.
21. Combustion of a fuel in a boiler furnace should be performed in what
conditions? ANS >> There should be a minimum of excess air.
22. What type of oil burner is used when oil is supplied under high pressure? ANS
>> -
Mechanical Atomizing Burner
23. An air atomizing compressor is usually what type? ANS >> A rotary type.
https://www.stuvia.com/user/Mboffin
