NYC CUSTODIAN ENGINEER
PROFESSIONAL EXAMINATION - SET 2
QUESTIONS AND ANSWERS
1. When testing a low-water fuel cut-off on a low-pressure steam boiler by blowing down the
float chamber, how often should this procedure typically be performed while the boiler is in
operation?
A. Once per month
B. Every shift or at least daily
C. Only during the annual inspection
D. Every six months
Answer: B
Conceptual Explanation: To ensure the safety mechanism is functional and free of sludge,
low-water cut-offs should be tested daily or per shift according to NYC heating protocols
and manufacturer recommendations.
2. What is the primary function of a steam trap in a heating system?
A. To increase the pressure of the steam
,B. To act as a secondary safety relief valve
C. To regulate the temperature of the boiler water
D. To discharge condensate and air without losing live steam
Answer: D
Conceptual Explanation: Steam traps are automatic valves that filter out condensed
steam (condensate) and non-condensable gases like air without letting steam escape.
3. In a NYC public building, which FDNY Certificate of Fitness is generally required to supervise
a standpipe system and a sprinkler system?
A. F-01
B. P-99
C. S-12 and S-13
D. G-60
Answer: C
Conceptual Explanation: S-12 (Citywide Sprinkler System) and S-13 (Citywide Standpipe
System) are the specific certifications required for the supervision of these fire protection
systems.
4. If a centrifugal pump is ‘cavitating’, what is the most likely cause?
A. Pressure at the suction inlet has dropped below the vapor pressure of the liquid
B. The pump is running too slow
, C. The discharge valve is fully open
D. The motor is wired in reverse
Answer: A
Conceptual Explanation: Cavitation occurs when bubbles form in a liquid due to low
pressure at the suction side and then collapse violently, potentially damaging the impeller.
5. Which chemical is commonly used to increase the pH of boiler water to prevent acidic
corrosion?
A. Sulfuric Acid
B. Sodium Hydroxide (Caustic Soda)
C. Sodium Chloride
D. Carbon Dioxide
Answer: B
Conceptual Explanation: Sodium hydroxide is an alkaline substance used to raise pH
levels, neutralizing acidity that causes corrosion in steel boilers.
6. According to NYC DOB regulations, a ‘High Pressure’ boiler is defined as a boiler operating
at a steam pressure of more than:
A. 5 psi
B. 10 psi
C. 15 psi
PROFESSIONAL EXAMINATION - SET 2
QUESTIONS AND ANSWERS
1. When testing a low-water fuel cut-off on a low-pressure steam boiler by blowing down the
float chamber, how often should this procedure typically be performed while the boiler is in
operation?
A. Once per month
B. Every shift or at least daily
C. Only during the annual inspection
D. Every six months
Answer: B
Conceptual Explanation: To ensure the safety mechanism is functional and free of sludge,
low-water cut-offs should be tested daily or per shift according to NYC heating protocols
and manufacturer recommendations.
2. What is the primary function of a steam trap in a heating system?
A. To increase the pressure of the steam
,B. To act as a secondary safety relief valve
C. To regulate the temperature of the boiler water
D. To discharge condensate and air without losing live steam
Answer: D
Conceptual Explanation: Steam traps are automatic valves that filter out condensed
steam (condensate) and non-condensable gases like air without letting steam escape.
3. In a NYC public building, which FDNY Certificate of Fitness is generally required to supervise
a standpipe system and a sprinkler system?
A. F-01
B. P-99
C. S-12 and S-13
D. G-60
Answer: C
Conceptual Explanation: S-12 (Citywide Sprinkler System) and S-13 (Citywide Standpipe
System) are the specific certifications required for the supervision of these fire protection
systems.
4. If a centrifugal pump is ‘cavitating’, what is the most likely cause?
A. Pressure at the suction inlet has dropped below the vapor pressure of the liquid
B. The pump is running too slow
, C. The discharge valve is fully open
D. The motor is wired in reverse
Answer: A
Conceptual Explanation: Cavitation occurs when bubbles form in a liquid due to low
pressure at the suction side and then collapse violently, potentially damaging the impeller.
5. Which chemical is commonly used to increase the pH of boiler water to prevent acidic
corrosion?
A. Sulfuric Acid
B. Sodium Hydroxide (Caustic Soda)
C. Sodium Chloride
D. Carbon Dioxide
Answer: B
Conceptual Explanation: Sodium hydroxide is an alkaline substance used to raise pH
levels, neutralizing acidity that causes corrosion in steel boilers.
6. According to NYC DOB regulations, a ‘High Pressure’ boiler is defined as a boiler operating
at a steam pressure of more than:
A. 5 psi
B. 10 psi
C. 15 psi
