NYC CUSTODIAN ENGINEER FINAL
EXAM 2026/2027 QUESTIONS AND
ANSWERS
1. According to NYC Boiler Code, what is the maximum allowable working pressure (MAWP)
for a low-pressure steam boiler?
A. 10 psi
B. 15 psi
C. 100 psi
D. 250 psi
Answer: B
Conceptual Explanation: Low-pressure steam boilers are designed to operate at a
pressure not exceeding 15 psi. High-pressure boilers operate above this limit.
2. In a steam heating system, what is the primary function of a Hartford Loop?
A. To equalize pressure between the header and the return line
B. To separate air from the condensate return
C. To prevent the boiler water level from dropping below the lowest safe waterline in the
event of a leak
,D. To increase the velocity of steam entering the main
Answer: C
Conceptual Explanation: The Hartford Loop is a piping arrangement that prevents total
loss of boiler water if a leak develops in the return line by utilizing a hydraulic seal.
3. Which mechanical device is used to maintain a constant pressure in a domestic water
supply for a high-rise building?
A. Ejector pump
B. Check valve
C. Pressure reducing valve (PRV)
D. Variable Frequency Drive (VFD) booster pump system
Answer: D
Conceptual Explanation: VFD systems adjust motor speed to maintain constant discharge
pressure regardless of the flow demand in high-rise structures.
4. What phenomenon occurs when the suction pressure of a centrifugal pump falls below the
vapor pressure of the liquid?
A. Cavitation
B. Priming
C. Surging
D. Water hammer
, Answer: A
Conceptual Explanation: Cavitation involves the formation and collapse of vapor bubbles,
which can cause significant damage to the pump impeller.
5. Under NYC Fire Code, how often must a hydrostatic pressure test be performed on a
standpipe system?
A. Every 5 years
B. Every 3 years
C. Every year
D. Every 10 years
Answer: A
Conceptual Explanation: NYC Fire Code requires a hydrostatic pressure test for standpipe
systems every 5 years to ensure structural integrity.
6. A ‘Class B’ fire involves which of the following materials?
A. Ordinary combustibles like wood or paper
B. Combustible metals
C. Energized electrical equipment
D. Flammable liquids like oil, gasoline, or grease
Answer: D
EXAM 2026/2027 QUESTIONS AND
ANSWERS
1. According to NYC Boiler Code, what is the maximum allowable working pressure (MAWP)
for a low-pressure steam boiler?
A. 10 psi
B. 15 psi
C. 100 psi
D. 250 psi
Answer: B
Conceptual Explanation: Low-pressure steam boilers are designed to operate at a
pressure not exceeding 15 psi. High-pressure boilers operate above this limit.
2. In a steam heating system, what is the primary function of a Hartford Loop?
A. To equalize pressure between the header and the return line
B. To separate air from the condensate return
C. To prevent the boiler water level from dropping below the lowest safe waterline in the
event of a leak
,D. To increase the velocity of steam entering the main
Answer: C
Conceptual Explanation: The Hartford Loop is a piping arrangement that prevents total
loss of boiler water if a leak develops in the return line by utilizing a hydraulic seal.
3. Which mechanical device is used to maintain a constant pressure in a domestic water
supply for a high-rise building?
A. Ejector pump
B. Check valve
C. Pressure reducing valve (PRV)
D. Variable Frequency Drive (VFD) booster pump system
Answer: D
Conceptual Explanation: VFD systems adjust motor speed to maintain constant discharge
pressure regardless of the flow demand in high-rise structures.
4. What phenomenon occurs when the suction pressure of a centrifugal pump falls below the
vapor pressure of the liquid?
A. Cavitation
B. Priming
C. Surging
D. Water hammer
, Answer: A
Conceptual Explanation: Cavitation involves the formation and collapse of vapor bubbles,
which can cause significant damage to the pump impeller.
5. Under NYC Fire Code, how often must a hydrostatic pressure test be performed on a
standpipe system?
A. Every 5 years
B. Every 3 years
C. Every year
D. Every 10 years
Answer: A
Conceptual Explanation: NYC Fire Code requires a hydrostatic pressure test for standpipe
systems every 5 years to ensure structural integrity.
6. A ‘Class B’ fire involves which of the following materials?
A. Ordinary combustibles like wood or paper
B. Combustible metals
C. Energized electrical equipment
D. Flammable liquids like oil, gasoline, or grease
Answer: D
