ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
1. What must be located outside a Class T machinery room?
Select one:
a. Spare flashlights
b. Disposable coveralls
c. Machinery shut off switch
d. Light switches: c
2. Degradation of heat transfer fluid of a hot oil system will begin to occur if:
Select one:
a. The oil filter is not serviced regularly
b. The oil temperature is above a specified range, for an extended period of
time
c. The oil is allowed to churn in the circulating pump
d. The oil becomes too viscous: b
3. Dry and flooded evaporators differ primarily in what respect?
Select one:
a. Dry evaporators use low-side floats, whereas flooded evaporators use
high-side floats
b. Flooded systems primarily use Group B1 and B2 refrigerants
c. The heat transfer surfaces of a flooded evaporator are kept covered with
liquid refrigerant
d. The dry evaporator is designed to cool gases only: c
4. It is good design practice to select a steam coil size so that:
Select one:
a. At least 10% of the coil capacity is needed when the air temperature at the
coil inlet is €"5°C
b. At least 80% of the coil capacity is needed when the air temperature at the
coil inlet is €"1°C
c. At least 40% of the coil capacity is needed when the air temperature entering
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
the coil is €"1°C
d. 100% of the coil capacity is needed when the air temperature entering the
coil is €"1°C: c
5. The final step when replacing a firetube is:
Select one:
a. Re-expansion
b. Hydrostatic test
c. Seal welding
d. Annealing the tube ends: b
6. If a boiler sustains a low water condition
Select one:
a. open the safety valve or drum vent valve to release pressure.
b. use cool feedwater to quench any overheated heating surface.
c. shut down the burner, let the boiler cool slowly, then drain and inspect it for
damage due to overheating.
d. immediately feed water into the boiler to raise the level.: c
7. An advantage of a pump using a mechanical seal is:
Select one:
a. Ease of repair
b. Less lubrication
c. Less maintenance
d. Lower first cost: c
8. For economical operation, the steam supply to a steam engine is cut off once
the piston has traveled of its stroke.
Select one:
a. 1
b. 75% to 90%
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
c. 1/2 to 5/8
d. 1/4 to 1/3: d
9. A high stack temperature in a hot oil heater may indicate:
Select one:
a. Inadequate combustion air
b. A tube failure
c. Excessive oil flow
d. Improper fuel-air ratio: b
10. The type of pump normally used with a hot oil system is a:
Select one:
a. Sliding vane pump
b. Rotary screw pump
c. Conventional, single stage centrifugal pump
d. Multistage reciprocating pump: c
11. Temperature relief devices can open on a rise in temperature by the expan-
sion of a wax-filled rod or by the:
Select one:
a. Action of a bellows
b. Action of a bi-metal strip
c. Melting of a fusible link
d. Melting of the alloy in a fusible plug: d
12. Who should verify a steam boiler lockout?
Select one:
a. Each and every contractor or employee working on the boiler.
b. A representative of the plant Workplace Safety and Health committee.
c. A second qualified operator.
d. Nobody.: c
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
13. In a circulating domestic hot water system, automatic air vents
Select one:
a. Keep air from entering the water, thus inhibiting corrosion
b. Aerate the water
c. Remove air that is released when water is heated
d. Relieve pressure from the hydro-pneumatic tanks: c
14. An acceptable pH value for boiler water is:
Select one:
a. 8.35
b. 10.5
c. 6.95
d. 7: b
15. With regard to plant operations, the acronym "STAR" stands for
Select one:
a. Stop, Think, Assess, Repeat
b. Start, Think, Assess, Repeat
c. Start, Take readings, Adjust, Review
d. Stop, Think, Act, Review: d
16. Wear rings are usually constructed of:
Select one:
a. Ceramics or aluminum
b. Graphite or bronze
c. Bronze or cast iron
d. Steel or alloy steel: c
17. The CSA B52 code requires that shall be provided on all
systems operating above atmospheric pressure.
Select one:
a. purgers
2026-2027
1. What must be located outside a Class T machinery room?
Select one:
a. Spare flashlights
b. Disposable coveralls
c. Machinery shut off switch
d. Light switches: c
2. Degradation of heat transfer fluid of a hot oil system will begin to occur if:
Select one:
a. The oil filter is not serviced regularly
b. The oil temperature is above a specified range, for an extended period of
time
c. The oil is allowed to churn in the circulating pump
d. The oil becomes too viscous: b
3. Dry and flooded evaporators differ primarily in what respect?
Select one:
a. Dry evaporators use low-side floats, whereas flooded evaporators use
high-side floats
b. Flooded systems primarily use Group B1 and B2 refrigerants
c. The heat transfer surfaces of a flooded evaporator are kept covered with
liquid refrigerant
d. The dry evaporator is designed to cool gases only: c
4. It is good design practice to select a steam coil size so that:
Select one:
a. At least 10% of the coil capacity is needed when the air temperature at the
coil inlet is €"5°C
b. At least 80% of the coil capacity is needed when the air temperature at the
coil inlet is €"1°C
c. At least 40% of the coil capacity is needed when the air temperature entering
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
the coil is €"1°C
d. 100% of the coil capacity is needed when the air temperature entering the
coil is €"1°C: c
5. The final step when replacing a firetube is:
Select one:
a. Re-expansion
b. Hydrostatic test
c. Seal welding
d. Annealing the tube ends: b
6. If a boiler sustains a low water condition
Select one:
a. open the safety valve or drum vent valve to release pressure.
b. use cool feedwater to quench any overheated heating surface.
c. shut down the burner, let the boiler cool slowly, then drain and inspect it for
damage due to overheating.
d. immediately feed water into the boiler to raise the level.: c
7. An advantage of a pump using a mechanical seal is:
Select one:
a. Ease of repair
b. Less lubrication
c. Less maintenance
d. Lower first cost: c
8. For economical operation, the steam supply to a steam engine is cut off once
the piston has traveled of its stroke.
Select one:
a. 1
b. 75% to 90%
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
c. 1/2 to 5/8
d. 1/4 to 1/3: d
9. A high stack temperature in a hot oil heater may indicate:
Select one:
a. Inadequate combustion air
b. A tube failure
c. Excessive oil flow
d. Improper fuel-air ratio: b
10. The type of pump normally used with a hot oil system is a:
Select one:
a. Sliding vane pump
b. Rotary screw pump
c. Conventional, single stage centrifugal pump
d. Multistage reciprocating pump: c
11. Temperature relief devices can open on a rise in temperature by the expan-
sion of a wax-filled rod or by the:
Select one:
a. Action of a bellows
b. Action of a bi-metal strip
c. Melting of a fusible link
d. Melting of the alloy in a fusible plug: d
12. Who should verify a steam boiler lockout?
Select one:
a. Each and every contractor or employee working on the boiler.
b. A representative of the plant Workplace Safety and Health committee.
c. A second qualified operator.
d. Nobody.: c
,ABSA- 4th Class Part B - Comprehensive Exam 2 Questions with correct anwers
2026-2027
13. In a circulating domestic hot water system, automatic air vents
Select one:
a. Keep air from entering the water, thus inhibiting corrosion
b. Aerate the water
c. Remove air that is released when water is heated
d. Relieve pressure from the hydro-pneumatic tanks: c
14. An acceptable pH value for boiler water is:
Select one:
a. 8.35
b. 10.5
c. 6.95
d. 7: b
15. With regard to plant operations, the acronym "STAR" stands for
Select one:
a. Stop, Think, Assess, Repeat
b. Start, Think, Assess, Repeat
c. Start, Take readings, Adjust, Review
d. Stop, Think, Act, Review: d
16. Wear rings are usually constructed of:
Select one:
a. Ceramics or aluminum
b. Graphite or bronze
c. Bronze or cast iron
d. Steel or alloy steel: c
17. The CSA B52 code requires that shall be provided on all
systems operating above atmospheric pressure.
Select one:
a. purgers
