F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
Question 1
A wet-pipe sprinkler system is supplied by a municipal main with a static pressure of 72 psi and a
residual pressure of 58 psi at 1,000 gpm. Which test information is most critical for hydraulic
calculations under NFPA 13?
A. Water temperature
B. Flow and residual pressure relationship
C. Pipe material only
D. Sprinkler finish
Answer: B
Explanation: NFPA 13 hydraulic calculations depend on water supply characteristics, specifically static
pressure, residual pressure, and corresponding flow. These values establish the water supply curve
used to verify system demand.
Question 2
Under NFPA 13, what is the principal function of a check valve in a fire protection riser assembly?
A. Increase pressure
B. Prevent reverse water flow
C. Reduce pipe friction loss
D. Operate supervisory alarms
Answer: B
Explanation: Check valves prevent reverse flow into water supplies and are commonly used in
backflow prevention assemblies and fire pump discharge piping.
Question 3
An ordinary hazard Group 2 occupancy requires a density of 0.20 gpm/ft² over 1,500 ft². What is the
required system demand before hose allowance?
A. 250 gpm
B. 300 gpm
C. 350 gpm
D. 400 gpm
Answer: B
Calculation:
0.20 × 1,500 = 300 gpm
Explanation: Hydraulic calculations begin by multiplying design density by remote area size.
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
Question 4
Which NFPA standard governs dry chemical extinguishing systems?
A. NFPA 17
B. NFPA 13
C. NFPA 25
D. NFPA 72
Answer: A
Explanation: NFPA 17 provides requirements for installation, testing, maintenance, and operation of
dry chemical fire suppression systems.
Question 5
A contractor is installing a clean agent system protecting a data center. Which standard applies?
A. NFPA 17A
B. NFPA 2001
C. NFPA 96
D. NFPA 24
Answer: B
Explanation: NFPA 2001 governs clean agent extinguishing systems including FM-200, Novec 1230,
and inert gas systems.
Question 6
Which sprinkler orientation is most suitable for exposed piping below ceilings?
A. Concealed
B. Sidewall
C. Upright
D. Flush
Answer: C
Explanation: Upright sprinklers are installed above piping and discharge upward against deflectors.
Question 7
According to OSHA, a trench deeper than what depth generally requires a protective system unless
excavated in stable rock?
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
A. 3 ft
B. 4 ft
C. 5 ft
D. 6 ft
Answer: C
Explanation: OSHA requires trench protection at depths of 5 feet or greater unless stable rock
conditions exist.
Question 8
A sprinkler requiring 25 gpm operates at what minimum pressure if its K-factor is 5.6?
A. 16 psi
B. 20 psi
C. 25 psi
D. 30 psi
Answer: B
Calculation:
Q = K√P
25 = 5.6√P
P ≈ 20 psi
Question 9
Under NFPA 25, how frequently should control valves be visually inspected in most systems?
A. Monthly
B. Weekly or monthly depending on valve supervision
C. Every 5 years
D. Annually
Answer: B
Explanation: NFPA 25 inspection frequency depends on supervision methods and valve types.
Question 10
Which component sends a signal when a control valve changes position?
A. Water motor gong
B. Tamper switch
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
C. Alarm check valve
D. Test header
Answer: B
Explanation: Tamper switches monitor valve position and transmit supervisory signals.
Question 11
A contractor installs Schedule 40 steel pipe instead of Schedule 10 as specified. What is the primary
hydraulic effect?
A. Greater friction loss
B. Lower friction loss due to larger internal diameter reduction resistance
C. No impact
D. Reduced sprinkler flow
Answer: B
Explanation: Pipe wall thickness affects internal diameter, influencing friction loss.
Question 12
Which type of sprinkler is most commonly installed along walls in hotel corridors?
A. Upright
B. Sidewall
C. ESFR
D. Open sprinkler
Answer: B
Explanation: Sidewall sprinklers efficiently protect narrow spaces and corridors.
Question 13
What is the primary purpose of a fire pump churn test?
A. Verify alarm function only
B. Measure no-flow pressure performance
C. Determine sprinkler density
D. Calculate friction loss
Answer: B
Explanation: Churn testing evaluates pump performance without system demand.
Latest Practice Exam (Updated Edition)
Question 1
A wet-pipe sprinkler system is supplied by a municipal main with a static pressure of 72 psi and a
residual pressure of 58 psi at 1,000 gpm. Which test information is most critical for hydraulic
calculations under NFPA 13?
A. Water temperature
B. Flow and residual pressure relationship
C. Pipe material only
D. Sprinkler finish
Answer: B
Explanation: NFPA 13 hydraulic calculations depend on water supply characteristics, specifically static
pressure, residual pressure, and corresponding flow. These values establish the water supply curve
used to verify system demand.
Question 2
Under NFPA 13, what is the principal function of a check valve in a fire protection riser assembly?
A. Increase pressure
B. Prevent reverse water flow
C. Reduce pipe friction loss
D. Operate supervisory alarms
Answer: B
Explanation: Check valves prevent reverse flow into water supplies and are commonly used in
backflow prevention assemblies and fire pump discharge piping.
Question 3
An ordinary hazard Group 2 occupancy requires a density of 0.20 gpm/ft² over 1,500 ft². What is the
required system demand before hose allowance?
A. 250 gpm
B. 300 gpm
C. 350 gpm
D. 400 gpm
Answer: B
Calculation:
0.20 × 1,500 = 300 gpm
Explanation: Hydraulic calculations begin by multiplying design density by remote area size.
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
Question 4
Which NFPA standard governs dry chemical extinguishing systems?
A. NFPA 17
B. NFPA 13
C. NFPA 25
D. NFPA 72
Answer: A
Explanation: NFPA 17 provides requirements for installation, testing, maintenance, and operation of
dry chemical fire suppression systems.
Question 5
A contractor is installing a clean agent system protecting a data center. Which standard applies?
A. NFPA 17A
B. NFPA 2001
C. NFPA 96
D. NFPA 24
Answer: B
Explanation: NFPA 2001 governs clean agent extinguishing systems including FM-200, Novec 1230,
and inert gas systems.
Question 6
Which sprinkler orientation is most suitable for exposed piping below ceilings?
A. Concealed
B. Sidewall
C. Upright
D. Flush
Answer: C
Explanation: Upright sprinklers are installed above piping and discharge upward against deflectors.
Question 7
According to OSHA, a trench deeper than what depth generally requires a protective system unless
excavated in stable rock?
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
A. 3 ft
B. 4 ft
C. 5 ft
D. 6 ft
Answer: C
Explanation: OSHA requires trench protection at depths of 5 feet or greater unless stable rock
conditions exist.
Question 8
A sprinkler requiring 25 gpm operates at what minimum pressure if its K-factor is 5.6?
A. 16 psi
B. 20 psi
C. 25 psi
D. 30 psi
Answer: B
Calculation:
Q = K√P
25 = 5.6√P
P ≈ 20 psi
Question 9
Under NFPA 25, how frequently should control valves be visually inspected in most systems?
A. Monthly
B. Weekly or monthly depending on valve supervision
C. Every 5 years
D. Annually
Answer: B
Explanation: NFPA 25 inspection frequency depends on supervision methods and valve types.
Question 10
Which component sends a signal when a control valve changes position?
A. Water motor gong
B. Tamper switch
, F35 Class DF Fire Suppression Installation Contractor
Latest Practice Exam (Updated Edition)
C. Alarm check valve
D. Test header
Answer: B
Explanation: Tamper switches monitor valve position and transmit supervisory signals.
Question 11
A contractor installs Schedule 40 steel pipe instead of Schedule 10 as specified. What is the primary
hydraulic effect?
A. Greater friction loss
B. Lower friction loss due to larger internal diameter reduction resistance
C. No impact
D. Reduced sprinkler flow
Answer: B
Explanation: Pipe wall thickness affects internal diameter, influencing friction loss.
Question 12
Which type of sprinkler is most commonly installed along walls in hotel corridors?
A. Upright
B. Sidewall
C. ESFR
D. Open sprinkler
Answer: B
Explanation: Sidewall sprinklers efficiently protect narrow spaces and corridors.
Question 13
What is the primary purpose of a fire pump churn test?
A. Verify alarm function only
B. Measure no-flow pressure performance
C. Determine sprinkler density
D. Calculate friction loss
Answer: B
Explanation: Churn testing evaluates pump performance without system demand.
