NFPA NFPA 13 Sprinkler Systems 3 — Questions and Answers
Question 1: Under NFPA 13, how far must a sprinkler deflector be positioned below a smooth flat ceiling for a standard pendent sprinkler?
- 1 to 4 inches
- 1 to 12 inches (Correct answer)
- 2 to 6 inches
- 4 to 8 inches
Correct answer: 1 to 12 inches
NFPA 13 requires the deflector of a standard pendent sprinkler to be positioned 1 to 12 inches below a smooth flat ceiling.
Question 2: What is the minimum required flow pressure at the most remote sprinkler in an NFPA 13 light hazard system?
- 5 psi
- 7 psi
- 10 psi (Correct answer)
- 15 psi
Correct answer: 10 psi
NFPA 13 requires a minimum residual pressure of 7 psi at the most remote sprinkler, but design pressure at each sprinkler must meet the hydraulic calculation, commonly 7 psi minimum.
Question 3: According to NFPA 13, which component must be provided at the base of each sprinkler riser to facilitate system testing and maintenance?
- Check valve
- Butterfly valve with tamper switch (Correct answer)
- Inspector's test connection
- Pressure gauge
Correct answer: Butterfly valve with tamper switch
NFPA 13 requires a supervised control valve (such as an OS&Y or butterfly valve with a tamper switch) at the base of each riser.
Question 4: Under NFPA 13, what is required when a sprinkler system is installed in a building with a combustible concealed space?
- No special requirements
- Sprinklers must be installed in the concealed space (Correct answer)
- Only smoke detectors are required
- The space must be filled with fire retardant foam
Correct answer: Sprinklers must be installed in the concealed space
NFPA 13 requires sprinklers in combustible concealed spaces unless specific exemptions based on construction type and insulation apply.
Question 5: What is the maximum permitted distance between sprinklers along a branch line under NFPA 13 for light hazard occupancies?
- 10 feet
- 15 feet (Correct answer)
- 20 feet
- 25 feet
Correct answer: 15 feet
NFPA 13 limits the maximum distance between sprinklers along a branch line to 15 feet in light hazard occupancies.
Question 6: Under NFPA 13, what type of fitting is required when changing direction on a sprinkler branch line to ensure proper drainage?
- 90-degree elbow
- 45-degree elbow
- Drain plug
- Drop nipple with a drip leg (Correct answer)
Correct answer: Drop nipple with a drip leg
NFPA 13 requires that branch lines be pitched to drain, using drop nipples or equivalent fittings to ensure water drains to a low point.
NFPA NFPA 13 Sprinkler Systems 3
Under NFPA 13, how far must a sprinkler deflector be positioned below a smooth flat ceiling for a standard pendent sprinkler?