KENTUCKY BOILER CONTRACTOR EXAM PRACTICE TEST (2025)
Multiple-Choice Questions | Based on KRS Chapter 236, 815 KAR, and ASME
BPVC | Verified Rationales
1. Under ASME Section I, what is the minimum required thickness for a boiler head
(tubesheet) in a fire-tube boiler?
A) 1/4 inch
B) 3/8 inch
C) 1/2 inch
D) 5/8 inch
Correct Answer: B
Rationale: ASME Section I requires a minimum head thickness of 3/8 inch for fire-tube
boiler tubesheets. This ensures adequate strength to withstand the internal pressure and
stresses from the tube-to-tubesheet joints. Thinner heads are not permitted.
2. In Kentucky, what is the required frequency for testing the low-water cutoff
(LWCO) on a steam boiler?
A) Daily
B) Weekly
C) Monthly
D) Annually
Correct Answer: A
Rationale: Under 815 KAR 10:050, the LWCO should be tested daily by slowly draining the
boiler (or lowering the water level) to ensure the burner shuts off at the proper water level.
This is a critical safety check to prevent dry-firing.
,3. What is the maximum allowable working pressure (MAWP) for a boiler that has
a safety valve set at 150 psig?
A) 140 psig
B) 145 psig
C) 150 psig
D) 155 psig
Correct Answer: C
Rationale: The safety valve is set to the MAWP (or slightly above, up to 3% above MAWP
for boilers with multiple valves). If the safety valve is set at 150 psig, the MAWP is 150
psig. The valve will open if the pressure exceeds this value.
4. Under Kentucky regulations, who is authorized to perform a hydrostatic test on
a boiler after a major repair?
A) The boiler operator
B) The boiler owner
C) A Kentucky-licensed Boiler Contractor under the supervision of a DHBC inspector
D) Any licensed professional engineer
Correct Answer: C
Rationale: A hydrostatic test after a major repair must be performed by a Kentucky-
licensed Boiler Contractor and witnessed by a DHBC inspector. The inspector must certify
that the test was performed correctly and that the boiler is safe to operate.
5. What is the function of a "flame scanner" in a boiler?
A) To ignite the burner
B) To monitor the presence of a stable flame and shut off fuel if the flame is lost
C) To adjust the fuel-to-air ratio
D) To measure the temperature of the flame
Correct Answer: B
Rationale: The flame scanner (UV or IR) continuously monitors the burner flame. If the
,flame is lost, the scanner sends a signal to the combustion controller, which shuts off the
fuel supply within 2–4 seconds to prevent a fuel buildup and explosion.
6. In Kentucky, what is the maximum fine for operating a boiler without a valid
inspection certificate?
A) $500 per day
B) $1,000 per day
C) $5,000 per day
D) $10,000 per day
Correct Answer: C
Rationale: Under KRS 236.990, operating a boiler without a valid inspection certificate is a
Class A misdemeanor, punishable by a fine of up to $5,000 per day and/or imprisonment.
Each day of operation is a separate violation.
7. Which of the following is the correct formula for calculating the required safety
valve capacity for a power boiler?
A) Capacity = Heating surface x 1.5
B) Capacity = Heating surface x 0.5
C) Capacity is determined by the boiler's MAWP and is calculated per ASME Section I
D) Capacity is determined by the fuel type
Correct Answer: C
Rationale: ASME Section I provides specific formulas and tables for calculating the required
safety valve capacity based on the boiler's heating surface, MAWP, and other factors. The
capacity must be sufficient to release all steam the boiler can generate without exceeding
the MAWP by more than 6%.
8. What is the purpose of a "steam separator" in a boiler system?
A) To separate steam from water
B) To remove moisture from steam (dry the steam)
, C) To increase steam pressure
D) To reduce steam temperature
Correct Answer: B
Rationale: A steam separator removes moisture droplets from the steam, producing dry
saturated steam. This is important for steam turbines and equipment that require dry
steam to prevent erosion and corrosion.
9. Under Kentucky law, a boiler contractor must maintain workers' compensation
insurance for all employees. What is the minimum requirement?
A) $100,000
B) $300,000
C) $500,000
D) As required by Kentucky workers' compensation law (no minimum specified, but
coverage is mandatory)
Correct Answer: D
Rationale: Kentucky law requires all employers with one or more employees to carry
workers' compensation insurance. The coverage amounts are set by state law. Failure to
carry workers' compensation insurance can result in fines and loss of license.
10. What is the maximum allowable temperature for a hot water boiler with a 30
psig pressure relief valve?
A) 200°F
B) 210°F
C) 250°F
D) 300°F
Correct Answer: C
Rationale: A hot water boiler with a 30 psig relief valve is a low-pressure boiler, limited to
a maximum temperature of 250°F. Above 250°F, it is classified as high-pressure regardless
of pressure.
Multiple-Choice Questions | Based on KRS Chapter 236, 815 KAR, and ASME
BPVC | Verified Rationales
1. Under ASME Section I, what is the minimum required thickness for a boiler head
(tubesheet) in a fire-tube boiler?
A) 1/4 inch
B) 3/8 inch
C) 1/2 inch
D) 5/8 inch
Correct Answer: B
Rationale: ASME Section I requires a minimum head thickness of 3/8 inch for fire-tube
boiler tubesheets. This ensures adequate strength to withstand the internal pressure and
stresses from the tube-to-tubesheet joints. Thinner heads are not permitted.
2. In Kentucky, what is the required frequency for testing the low-water cutoff
(LWCO) on a steam boiler?
A) Daily
B) Weekly
C) Monthly
D) Annually
Correct Answer: A
Rationale: Under 815 KAR 10:050, the LWCO should be tested daily by slowly draining the
boiler (or lowering the water level) to ensure the burner shuts off at the proper water level.
This is a critical safety check to prevent dry-firing.
,3. What is the maximum allowable working pressure (MAWP) for a boiler that has
a safety valve set at 150 psig?
A) 140 psig
B) 145 psig
C) 150 psig
D) 155 psig
Correct Answer: C
Rationale: The safety valve is set to the MAWP (or slightly above, up to 3% above MAWP
for boilers with multiple valves). If the safety valve is set at 150 psig, the MAWP is 150
psig. The valve will open if the pressure exceeds this value.
4. Under Kentucky regulations, who is authorized to perform a hydrostatic test on
a boiler after a major repair?
A) The boiler operator
B) The boiler owner
C) A Kentucky-licensed Boiler Contractor under the supervision of a DHBC inspector
D) Any licensed professional engineer
Correct Answer: C
Rationale: A hydrostatic test after a major repair must be performed by a Kentucky-
licensed Boiler Contractor and witnessed by a DHBC inspector. The inspector must certify
that the test was performed correctly and that the boiler is safe to operate.
5. What is the function of a "flame scanner" in a boiler?
A) To ignite the burner
B) To monitor the presence of a stable flame and shut off fuel if the flame is lost
C) To adjust the fuel-to-air ratio
D) To measure the temperature of the flame
Correct Answer: B
Rationale: The flame scanner (UV or IR) continuously monitors the burner flame. If the
,flame is lost, the scanner sends a signal to the combustion controller, which shuts off the
fuel supply within 2–4 seconds to prevent a fuel buildup and explosion.
6. In Kentucky, what is the maximum fine for operating a boiler without a valid
inspection certificate?
A) $500 per day
B) $1,000 per day
C) $5,000 per day
D) $10,000 per day
Correct Answer: C
Rationale: Under KRS 236.990, operating a boiler without a valid inspection certificate is a
Class A misdemeanor, punishable by a fine of up to $5,000 per day and/or imprisonment.
Each day of operation is a separate violation.
7. Which of the following is the correct formula for calculating the required safety
valve capacity for a power boiler?
A) Capacity = Heating surface x 1.5
B) Capacity = Heating surface x 0.5
C) Capacity is determined by the boiler's MAWP and is calculated per ASME Section I
D) Capacity is determined by the fuel type
Correct Answer: C
Rationale: ASME Section I provides specific formulas and tables for calculating the required
safety valve capacity based on the boiler's heating surface, MAWP, and other factors. The
capacity must be sufficient to release all steam the boiler can generate without exceeding
the MAWP by more than 6%.
8. What is the purpose of a "steam separator" in a boiler system?
A) To separate steam from water
B) To remove moisture from steam (dry the steam)
, C) To increase steam pressure
D) To reduce steam temperature
Correct Answer: B
Rationale: A steam separator removes moisture droplets from the steam, producing dry
saturated steam. This is important for steam turbines and equipment that require dry
steam to prevent erosion and corrosion.
9. Under Kentucky law, a boiler contractor must maintain workers' compensation
insurance for all employees. What is the minimum requirement?
A) $100,000
B) $300,000
C) $500,000
D) As required by Kentucky workers' compensation law (no minimum specified, but
coverage is mandatory)
Correct Answer: D
Rationale: Kentucky law requires all employers with one or more employees to carry
workers' compensation insurance. The coverage amounts are set by state law. Failure to
carry workers' compensation insurance can result in fines and loss of license.
10. What is the maximum allowable temperature for a hot water boiler with a 30
psig pressure relief valve?
A) 200°F
B) 210°F
C) 250°F
D) 300°F
Correct Answer: C
Rationale: A hot water boiler with a 30 psig relief valve is a low-pressure boiler, limited to
a maximum temperature of 250°F. Above 250°F, it is classified as high-pressure regardless
of pressure.
