NCCER | Boilermaker
OBJECTIVE ASSESSMENT - EXAM
Boilermaker Maintenance NCCER
Exam, Questions & Correct
Answers, 100% Guaranteed Pass ||
Complete A+ Guide
Certification Exam
100 100%
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
• Boiler Types, Components, and Operating Principles • Welding Processes, Symbols, and Joint Design
• Rigging Hardware, Load Calculations, and Crane Safety • Tube Rolling, Patching, and Pressure Testing
• P&ID Interpretation, Isometric Drawings, and Specifications
COVER PAGE - 1
,SECTION 1 | Boiler Fundamentals and Safety | Q1-Q20 | Boilermaker Maintenance NCCER Exam, Questions & Corre
Q1 Question 1 of 100
A 45-year-old boilermaker is inspecting a watertube boiler at a power plant and notices that the
water level in the steam drum is dropping rapidly while the feedwater pump is running normally.
Which of the following is the most likely cause of this condition?
A. The steam drum blowdown valve is stuck open
B. The economizer tubes have developed a leak
C. The superheater header drain is partially closed
D. The feedwater regulator is malfunctioning and bypassing water
Correct Answer: B
Rationale:
A leak in the economizer tubes allows water to escape from the feedwater path before reaching the steam drum,
causing the drum level to drop despite normal pump operation. A stuck-open blowdown would cause loss but is
typically visible, and a malfunctioning regulator would more likely overfeed than underfeed.
Q2 Question 2 of 100
During a routine safety inspection, a boilermaker discovers that the safety relief valves on a
high-pressure boiler have not been tested in 18 months. According to standard ASME boiler code
requirements, what is the maximum recommended interval between safety valve testing?
A. 6 months
B. 12 months
C. 24 months
D. 36 months
Correct Answer: B
Rationale:
ASME Section I recommends annual testing of safety relief valves to ensure they open at the correct set pressure and
reseat properly. Waiting 18 months exceeds this interval and creates a significant safety hazard.
Q3 Question 3 of 100
A junior boilermaker is tasked with measuring the thickness of a boiler drum shell using ultrasonic
testing. The original thickness was 1.5 inches, and the current reading shows 1.35 inches. What
percentage of wall loss has occurred, and does this typically require repair or replacement?
A. 5% wall loss - monitor only
B. 10% wall loss - monitor only
C. 10% wall loss - repair or replace required
, D. 15% wall loss - immediate replacement required
Correct Answer: C
Rationale:
Wall loss is (1.5 - 1.35) / 1.5 = 0..5 = 10%. At 10% uniform wall loss on a pressure vessel, repair or replacement
is generally required per NBIC guidelines, as continued operation risks failure under pressure.
Q4 Question 4 of 100
A firetube boiler operator reports that the boiler is producing wet steam and the steam quality has
degraded. The water level appears normal, and there is no visible foaming. Which component failure
is most likely responsible?
A. A ruptured firetube allowing combustion gases into the steam space
B. A failed steam separator (chevron drier) in the steam drum
C. A clogged feedwater strainer restricting flow
D. A leaking safety valve causing pressure drop
Correct Answer: B
Rationale:
The steam separator (chevron drier) removes entrained water droplets from steam. If it fails, steam quality degrades
even with normal water level and no foaming. A ruptured firetube would cause pressure loss and combustion issues,
not wet steam alone.
Q5 Question 5 of 100
A boilermaker is reviewing the boiler log sheets and notices that the stack temperature has risen
80 degF over the past month while the firing rate has remained constant. What is the most probable
cause of this gradual increase?
A. The burner air-fuel ratio has shifted to excess fuel
B. Soot and scale buildup on the fireside and waterside has reduced heat transfer efficiency
C. The forced-draft fan damper has closed partially, reducing combustion air
D. The feedwater temperature has increased, requiring less heat input
Correct Answer: B
Rationale:
Soot on fireside tubes and scale on waterside tubes act as insulators, reducing heat transfer. The boiler must burn
more fuel to maintain output, but since firing rate is constant, the stack temperature rises as less heat is absorbed.
Excess fuel would cause incomplete combustion, not just stack temperature rise.
Q6 Question 6 of 100
, During boiler startup, a boilermaker observes that the furnace pressure is reading slightly positive
(0.1 inches WC) while the induced-draft fan is running. What is the most appropriate immediate
action?
A. Increase the induced-draft fan speed to create more negative pressure
B. Reduce the firing rate to lower combustion gas volume
C. Check for blocked flue gas passages or damper malfunctions before increasing draft
D. Open the observation door to relieve pressure manually
Correct Answer: C
Rationale:
Positive furnace pressure during startup indicates a restriction in flue gas flow or a damper issue. Before adjusting fan
speed, the root cause must be identified to prevent flame rollout or structural damage. Opening an observation door is
dangerous with positive pressure.
Q7 Question 7 of 100
A maintenance team is preparing to enter a boiler drum for internal inspection. The confined space
entry permit requires atmospheric testing. In what order should the atmospheric tests be performed?
A. Oxygen first, then combustible gases, then toxic gases
B. Combustible gases first, then oxygen, then toxic gases
C. Toxic gases first, then oxygen, then combustible gases
D. Oxygen first, then toxic gases, then combustible gases
Correct Answer: A
Rationale:
OSHA and standard confined space protocols require testing oxygen levels first (to ensure the atmosphere is
breathable), followed by combustible gases (to prevent fire/explosion), then toxic gases. Testing in this order protects
personnel at each step.
Q8 Question 8 of 100
A boilermaker is installing new handhole and manhole gaskets on a boiler that operates at 250 psig
and 400 degF. Which gasket material is most appropriate for this service?
A. Rubber neoprene gasket
B. Compressed non-asbestos fiber (CNAF) gasket rated for 400 degF
C. Spiral-wound stainless steel gasket with flexible graphite filler
D. Cork-rubber composite gasket
Correct Answer: C
OBJECTIVE ASSESSMENT - EXAM
Boilermaker Maintenance NCCER
Exam, Questions & Correct
Answers, 100% Guaranteed Pass ||
Complete A+ Guide
Certification Exam
100 100%
QUESTIONS VERIFIED ANSWERS EDITION
TOPICS COVERED
• Boiler Types, Components, and Operating Principles • Welding Processes, Symbols, and Joint Design
• Rigging Hardware, Load Calculations, and Crane Safety • Tube Rolling, Patching, and Pressure Testing
• P&ID Interpretation, Isometric Drawings, and Specifications
COVER PAGE - 1
,SECTION 1 | Boiler Fundamentals and Safety | Q1-Q20 | Boilermaker Maintenance NCCER Exam, Questions & Corre
Q1 Question 1 of 100
A 45-year-old boilermaker is inspecting a watertube boiler at a power plant and notices that the
water level in the steam drum is dropping rapidly while the feedwater pump is running normally.
Which of the following is the most likely cause of this condition?
A. The steam drum blowdown valve is stuck open
B. The economizer tubes have developed a leak
C. The superheater header drain is partially closed
D. The feedwater regulator is malfunctioning and bypassing water
Correct Answer: B
Rationale:
A leak in the economizer tubes allows water to escape from the feedwater path before reaching the steam drum,
causing the drum level to drop despite normal pump operation. A stuck-open blowdown would cause loss but is
typically visible, and a malfunctioning regulator would more likely overfeed than underfeed.
Q2 Question 2 of 100
During a routine safety inspection, a boilermaker discovers that the safety relief valves on a
high-pressure boiler have not been tested in 18 months. According to standard ASME boiler code
requirements, what is the maximum recommended interval between safety valve testing?
A. 6 months
B. 12 months
C. 24 months
D. 36 months
Correct Answer: B
Rationale:
ASME Section I recommends annual testing of safety relief valves to ensure they open at the correct set pressure and
reseat properly. Waiting 18 months exceeds this interval and creates a significant safety hazard.
Q3 Question 3 of 100
A junior boilermaker is tasked with measuring the thickness of a boiler drum shell using ultrasonic
testing. The original thickness was 1.5 inches, and the current reading shows 1.35 inches. What
percentage of wall loss has occurred, and does this typically require repair or replacement?
A. 5% wall loss - monitor only
B. 10% wall loss - monitor only
C. 10% wall loss - repair or replace required
, D. 15% wall loss - immediate replacement required
Correct Answer: C
Rationale:
Wall loss is (1.5 - 1.35) / 1.5 = 0..5 = 10%. At 10% uniform wall loss on a pressure vessel, repair or replacement
is generally required per NBIC guidelines, as continued operation risks failure under pressure.
Q4 Question 4 of 100
A firetube boiler operator reports that the boiler is producing wet steam and the steam quality has
degraded. The water level appears normal, and there is no visible foaming. Which component failure
is most likely responsible?
A. A ruptured firetube allowing combustion gases into the steam space
B. A failed steam separator (chevron drier) in the steam drum
C. A clogged feedwater strainer restricting flow
D. A leaking safety valve causing pressure drop
Correct Answer: B
Rationale:
The steam separator (chevron drier) removes entrained water droplets from steam. If it fails, steam quality degrades
even with normal water level and no foaming. A ruptured firetube would cause pressure loss and combustion issues,
not wet steam alone.
Q5 Question 5 of 100
A boilermaker is reviewing the boiler log sheets and notices that the stack temperature has risen
80 degF over the past month while the firing rate has remained constant. What is the most probable
cause of this gradual increase?
A. The burner air-fuel ratio has shifted to excess fuel
B. Soot and scale buildup on the fireside and waterside has reduced heat transfer efficiency
C. The forced-draft fan damper has closed partially, reducing combustion air
D. The feedwater temperature has increased, requiring less heat input
Correct Answer: B
Rationale:
Soot on fireside tubes and scale on waterside tubes act as insulators, reducing heat transfer. The boiler must burn
more fuel to maintain output, but since firing rate is constant, the stack temperature rises as less heat is absorbed.
Excess fuel would cause incomplete combustion, not just stack temperature rise.
Q6 Question 6 of 100
, During boiler startup, a boilermaker observes that the furnace pressure is reading slightly positive
(0.1 inches WC) while the induced-draft fan is running. What is the most appropriate immediate
action?
A. Increase the induced-draft fan speed to create more negative pressure
B. Reduce the firing rate to lower combustion gas volume
C. Check for blocked flue gas passages or damper malfunctions before increasing draft
D. Open the observation door to relieve pressure manually
Correct Answer: C
Rationale:
Positive furnace pressure during startup indicates a restriction in flue gas flow or a damper issue. Before adjusting fan
speed, the root cause must be identified to prevent flame rollout or structural damage. Opening an observation door is
dangerous with positive pressure.
Q7 Question 7 of 100
A maintenance team is preparing to enter a boiler drum for internal inspection. The confined space
entry permit requires atmospheric testing. In what order should the atmospheric tests be performed?
A. Oxygen first, then combustible gases, then toxic gases
B. Combustible gases first, then oxygen, then toxic gases
C. Toxic gases first, then oxygen, then combustible gases
D. Oxygen first, then toxic gases, then combustible gases
Correct Answer: A
Rationale:
OSHA and standard confined space protocols require testing oxygen levels first (to ensure the atmosphere is
breathable), followed by combustible gases (to prevent fire/explosion), then toxic gases. Testing in this order protects
personnel at each step.
Q8 Question 8 of 100
A boilermaker is installing new handhole and manhole gaskets on a boiler that operates at 250 psig
and 400 degF. Which gasket material is most appropriate for this service?
A. Rubber neoprene gasket
B. Compressed non-asbestos fiber (CNAF) gasket rated for 400 degF
C. Spiral-wound stainless steel gasket with flexible graphite filler
D. Cork-rubber composite gasket
Correct Answer: C
