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NYC (DOB) Master Fire Suppression Piping Contractor
(Class A) Exam | Latest Verified Questions and Detailed
Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the NYC Master Fire
Suppression Piping Contractor (Class A) Exam, a time-limited computer-based test
administered by the New York City Department of Buildings (DOB). The exam assesses a
candidate’s ability to safely apply fire protection regulations and engineering principles to
real-world installations, covering NYC Construction Codes and Fire Code (with heavy
emphasis on Chapter 9), system types (wet pipe, dry pipe, pre-action, deluge, foam-water),
standpipe design and layout, hydraulic calculations for pipe sizing and water supply, fire
pump specifications per NFPA 20, component inspection and maintenance under NFPA 25,
and hazard classifications for determining appropriate system water demand.
QUESTION 1
A new warehouse is designed for storage of Class IV commodities on single-row racks
to a height of 20 ft. The sprinkler system is to be designed using the density/area
method. Which hazard classification is most appropriate for this occupancy according to
NFPA 13?
A) Light Hazard
B) Ordinary Hazard Group 1
C) Ordinary Hazard Group 2
D) Extra Hazard Group 1
CORRECT ANSWER: C
EXPERT RATIONALE: Class IV commodities in racks up to 20 ft under single-row racks
are classified as Ordinary Hazard Group 2 per NFPA 13 commodity and storage
classifications, requiring 0.20 gpm/ft² over 1500 ft² minimum.
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QUESTION 2
Per the NYC Building Code Chapter 9, what is the minimum required fire protection
rating for a fire barrier separating a Group S-1 storage occupancy from a Group B
business occupancy?
A) 1 hour
B) 2 hours
C) 3 hours
D) No separation required
CORRECT ANSWER: B
EXPERT RATIONALE: NYC Building Code Table 508.4 requires a 2-hour fire barrier
separation between Group S-1 and Group B occupancies in a non-sprinklered building;
if sprinklered, reduced ratings may apply, but Chapter 9 generally upholds IBC
separation with NYC amendments.
QUESTION 3
During a dry pipe sprinkler system inspection, you observe the air pressure gauge
reading 10 psi above the trip point. The system has a 6-inch main valve and a total
volume of 1200 gallons. How often must the air compressor and air maintenance device
be checked per NFPA 25?
A) Weekly
B) Monthly
C) Quarterly
D) Annually
CORRECT ANSWER: C
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EXPERT RATIONALE: NFPA 25 (2020 edition) Table 5.1.1.2 requires quarterly inspection
of air compressors and air maintenance devices on dry pipe systems, regardless of
system volume or pressure settings.
QUESTION 4
A 10-story residential building has a Class I wet standpipe system. What is the minimum
required residual pressure at the highest hose connection while flowing 500 gpm, per
NYC Building Code?
A) 65 psi
B) 80 psi
C) 100 psi
D) 125 psi
CORRECT ANSWER: C
EXPERT RATIONALE: NYC Building Code Section 905.4 requires a minimum residual
pressure of 100 psi at the outlet of the highest standpipe when flowing 500 gpm for a
Class I system, aligning with NFPA 14 but with NYC-specific enforcement.
QUESTION 5
When performing a hydraulic calculation for a tree sprinkler system, a designer must
account for friction loss in Schedule 40 steel pipe. For a flow of 80 gpm through 2-inch
pipe (ID 2.067 in.), what is the approximate friction loss per foot using the Hazen-
Williams formula with C=120?
A) 0.025 psi/ft
B) 0.051 psi/ft
C) 0.082 psi/ft
D) 0.117 psi/ft
CORRECT ANSWER: D
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EXPERT RATIONALE: Using Hazen-Williams p=(4.52Q^1.85)/(C^1.85d^4.87), Q=80,
d=2.067, C=120 yields approximately 0.117 psi/ft. This is a typical calculation for pipe
sizing.
QUESTION 6
A deluge system protecting an aircraft hangar must activate within what time from valve
operation to water delivery at the most remote nozzle?
A) 15 seconds
B) 30 seconds
C) 60 seconds
D) 120 seconds
CORRECT ANSWER: C
EXPERT RATIONALE: NFPA 13 requires that deluge systems deliver water to the most
remote nozzle within 60 seconds from activation of the detection system to ensure rapid
fire control in high-hazard areas.
QUESTION 7
A jockey pump is installed on a fire pump system to maintain system pressure. Per NFPA
20, the jockey pump should be sized to compensate for how much of the system’s
leakage rate?
A) 50% of leakage
B) 75% of leakage
C) 100% of leakage
D) 1 gpm minimum, plus leakage
CORRECT ANSWER: C
EXPERT RATIONALE: NFPA 20 states the jockey pump should maintain pressure without
unnecessary starting of the main fire pump; it is typically sized to replenish 100% of the
NYC (DOB) Master Fire Suppression Piping Contractor
(Class A) Exam | Latest Verified Questions and Detailed
Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the NYC Master Fire
Suppression Piping Contractor (Class A) Exam, a time-limited computer-based test
administered by the New York City Department of Buildings (DOB). The exam assesses a
candidate’s ability to safely apply fire protection regulations and engineering principles to
real-world installations, covering NYC Construction Codes and Fire Code (with heavy
emphasis on Chapter 9), system types (wet pipe, dry pipe, pre-action, deluge, foam-water),
standpipe design and layout, hydraulic calculations for pipe sizing and water supply, fire
pump specifications per NFPA 20, component inspection and maintenance under NFPA 25,
and hazard classifications for determining appropriate system water demand.
QUESTION 1
A new warehouse is designed for storage of Class IV commodities on single-row racks
to a height of 20 ft. The sprinkler system is to be designed using the density/area
method. Which hazard classification is most appropriate for this occupancy according to
NFPA 13?
A) Light Hazard
B) Ordinary Hazard Group 1
C) Ordinary Hazard Group 2
D) Extra Hazard Group 1
CORRECT ANSWER: C
EXPERT RATIONALE: Class IV commodities in racks up to 20 ft under single-row racks
are classified as Ordinary Hazard Group 2 per NFPA 13 commodity and storage
classifications, requiring 0.20 gpm/ft² over 1500 ft² minimum.
,2|Page
QUESTION 2
Per the NYC Building Code Chapter 9, what is the minimum required fire protection
rating for a fire barrier separating a Group S-1 storage occupancy from a Group B
business occupancy?
A) 1 hour
B) 2 hours
C) 3 hours
D) No separation required
CORRECT ANSWER: B
EXPERT RATIONALE: NYC Building Code Table 508.4 requires a 2-hour fire barrier
separation between Group S-1 and Group B occupancies in a non-sprinklered building;
if sprinklered, reduced ratings may apply, but Chapter 9 generally upholds IBC
separation with NYC amendments.
QUESTION 3
During a dry pipe sprinkler system inspection, you observe the air pressure gauge
reading 10 psi above the trip point. The system has a 6-inch main valve and a total
volume of 1200 gallons. How often must the air compressor and air maintenance device
be checked per NFPA 25?
A) Weekly
B) Monthly
C) Quarterly
D) Annually
CORRECT ANSWER: C
,3|Page
EXPERT RATIONALE: NFPA 25 (2020 edition) Table 5.1.1.2 requires quarterly inspection
of air compressors and air maintenance devices on dry pipe systems, regardless of
system volume or pressure settings.
QUESTION 4
A 10-story residential building has a Class I wet standpipe system. What is the minimum
required residual pressure at the highest hose connection while flowing 500 gpm, per
NYC Building Code?
A) 65 psi
B) 80 psi
C) 100 psi
D) 125 psi
CORRECT ANSWER: C
EXPERT RATIONALE: NYC Building Code Section 905.4 requires a minimum residual
pressure of 100 psi at the outlet of the highest standpipe when flowing 500 gpm for a
Class I system, aligning with NFPA 14 but with NYC-specific enforcement.
QUESTION 5
When performing a hydraulic calculation for a tree sprinkler system, a designer must
account for friction loss in Schedule 40 steel pipe. For a flow of 80 gpm through 2-inch
pipe (ID 2.067 in.), what is the approximate friction loss per foot using the Hazen-
Williams formula with C=120?
A) 0.025 psi/ft
B) 0.051 psi/ft
C) 0.082 psi/ft
D) 0.117 psi/ft
CORRECT ANSWER: D
, 4|Page
EXPERT RATIONALE: Using Hazen-Williams p=(4.52Q^1.85)/(C^1.85d^4.87), Q=80,
d=2.067, C=120 yields approximately 0.117 psi/ft. This is a typical calculation for pipe
sizing.
QUESTION 6
A deluge system protecting an aircraft hangar must activate within what time from valve
operation to water delivery at the most remote nozzle?
A) 15 seconds
B) 30 seconds
C) 60 seconds
D) 120 seconds
CORRECT ANSWER: C
EXPERT RATIONALE: NFPA 13 requires that deluge systems deliver water to the most
remote nozzle within 60 seconds from activation of the detection system to ensure rapid
fire control in high-hazard areas.
QUESTION 7
A jockey pump is installed on a fire pump system to maintain system pressure. Per NFPA
20, the jockey pump should be sized to compensate for how much of the system’s
leakage rate?
A) 50% of leakage
B) 75% of leakage
C) 100% of leakage
D) 1 gpm minimum, plus leakage
CORRECT ANSWER: C
EXPERT RATIONALE: NFPA 20 states the jockey pump should maintain pressure without
unnecessary starting of the main fire pump; it is typically sized to replenish 100% of the
