NYC HIGH PRESSURE PLANT TENDER (DCAS)
CERTIFICATION PRACTICE EXAM Questions
With Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
A+ Grade Guarantee Verified By Professionals
1. A high-pressure boiler is typically defined as operating above which
pressure threshold?
A. 15 psi
B. 30 psi
C. 100 psi
D. 500 psi
✔
Answer: C. 100 psi
Rationale: In NYC and ASME classifications, a high-pressure boiler generally
operates above 15 psi steam pressure for low-pressure systems, but high-
pressure plant equipment is commonly recognized at significantly higher
thresholds, typically above 100 psi depending on classification context.
2. The primary purpose of a boiler safety valve is to:
A. Regulate water level
B. Prevent overheating
C. Release excess pressure
D. Improve combustion efficiency
✔
,Answer: C. Release excess pressure
Rationale: A safety valve is a critical protective device designed to automatically
release steam when pressure exceeds safe operating limits.
3. Low water in a boiler primarily risks:
A. Increased fuel efficiency
B. Tube overheating and failure
C. Improved steam quality
D. Reduced corrosion
✔
Answer: B. Tube overheating and failure
Rationale: Low water conditions expose boiler tubes to extreme heat, leading to
deformation or catastrophic failure.
4. The function of a boiler feedwater pump is to:
A. Remove sludge
B. Supply water to the boiler
C. Increase steam temperature
D. Vent combustion gases
✔
Answer: B. Supply water to the boiler
Rationale: The feedwater pump maintains proper water level by delivering
treated water into the boiler system.
5. Which instrument measures boiler steam pressure?
A. Thermometer
B. Hygrometer
C. Pressure gauge
, D. Flow meter
✔
Answer: C. Pressure gauge
Rationale: A pressure gauge (steam gauge) is used to monitor internal boiler
pressure in real time.
6. The term “blowdown” refers to:
A. Increasing steam output
B. Removing sediment from boiler water
C. Testing combustion efficiency
D. Adding chemicals to fuel
✔
Answer: B. Removing sediment from boiler water
Rationale: Blowdown removes dissolved solids and sludge to maintain water
quality and prevent scale buildup.
7. Scale formation in a boiler primarily results from:
A. Oxygen in fuel
B. Dissolved minerals in water
C. Excess steam pressure
D. Poor insulation
✔
Answer: B. Dissolved minerals in water
Rationale: Calcium and magnesium salts precipitate and form scale on heat
transfer surfaces.
8. A boiler furnace explosion is most often caused by:
A. Excess water
, B. Fuel accumulation and delayed ignition
C. High feedwater quality
D. Proper ventilation
✔
Answer: B. Fuel accumulation and delayed ignition
Rationale: Unburned fuel buildup can ignite suddenly, causing a furnace
explosion.
9. The purpose of boiler water treatment is to:
A. Increase steam color
B. Prevent corrosion and scale
C. Reduce fuel cost only
D. Increase air pressure
✔
Answer: B. Prevent corrosion and scale
Rationale: Chemical treatment controls oxygen, pH, and mineral content to
protect boiler components.
10.A sight glass on a boiler is used to:
A. Measure pressure
B. Observe water level
C. Measure temperature
D. Control combustion
✔
Answer: B. Observe water level
Rationale: The sight glass provides a direct visual indication of boiler water
level.
CERTIFICATION PRACTICE EXAM Questions
With Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
A+ Grade Guarantee Verified By Professionals
1. A high-pressure boiler is typically defined as operating above which
pressure threshold?
A. 15 psi
B. 30 psi
C. 100 psi
D. 500 psi
✔
Answer: C. 100 psi
Rationale: In NYC and ASME classifications, a high-pressure boiler generally
operates above 15 psi steam pressure for low-pressure systems, but high-
pressure plant equipment is commonly recognized at significantly higher
thresholds, typically above 100 psi depending on classification context.
2. The primary purpose of a boiler safety valve is to:
A. Regulate water level
B. Prevent overheating
C. Release excess pressure
D. Improve combustion efficiency
✔
,Answer: C. Release excess pressure
Rationale: A safety valve is a critical protective device designed to automatically
release steam when pressure exceeds safe operating limits.
3. Low water in a boiler primarily risks:
A. Increased fuel efficiency
B. Tube overheating and failure
C. Improved steam quality
D. Reduced corrosion
✔
Answer: B. Tube overheating and failure
Rationale: Low water conditions expose boiler tubes to extreme heat, leading to
deformation or catastrophic failure.
4. The function of a boiler feedwater pump is to:
A. Remove sludge
B. Supply water to the boiler
C. Increase steam temperature
D. Vent combustion gases
✔
Answer: B. Supply water to the boiler
Rationale: The feedwater pump maintains proper water level by delivering
treated water into the boiler system.
5. Which instrument measures boiler steam pressure?
A. Thermometer
B. Hygrometer
C. Pressure gauge
, D. Flow meter
✔
Answer: C. Pressure gauge
Rationale: A pressure gauge (steam gauge) is used to monitor internal boiler
pressure in real time.
6. The term “blowdown” refers to:
A. Increasing steam output
B. Removing sediment from boiler water
C. Testing combustion efficiency
D. Adding chemicals to fuel
✔
Answer: B. Removing sediment from boiler water
Rationale: Blowdown removes dissolved solids and sludge to maintain water
quality and prevent scale buildup.
7. Scale formation in a boiler primarily results from:
A. Oxygen in fuel
B. Dissolved minerals in water
C. Excess steam pressure
D. Poor insulation
✔
Answer: B. Dissolved minerals in water
Rationale: Calcium and magnesium salts precipitate and form scale on heat
transfer surfaces.
8. A boiler furnace explosion is most often caused by:
A. Excess water
, B. Fuel accumulation and delayed ignition
C. High feedwater quality
D. Proper ventilation
✔
Answer: B. Fuel accumulation and delayed ignition
Rationale: Unburned fuel buildup can ignite suddenly, causing a furnace
explosion.
9. The purpose of boiler water treatment is to:
A. Increase steam color
B. Prevent corrosion and scale
C. Reduce fuel cost only
D. Increase air pressure
✔
Answer: B. Prevent corrosion and scale
Rationale: Chemical treatment controls oxygen, pH, and mineral content to
protect boiler components.
10.A sight glass on a boiler is used to:
A. Measure pressure
B. Observe water level
C. Measure temperature
D. Control combustion
✔
Answer: B. Observe water level
Rationale: The sight glass provides a direct visual indication of boiler water
level.
