S-13 Water Supply and Pressure Requirements 1 — Questions and Answers
Question 1: What is the minimum residual pressure required at the highest outlet of a Class I or Class III standpipe system in New York City during operation?
- 65 psi
- 100 psi (Correct answer)
- 75 psi
- 50 psi
Correct answer: 100 psi
FDNY and NFPA 14 require a minimum residual pressure of 100 psi at the hydraulically most remote outlet for Class I and Class III standpipe systems.
Question 2: What is the maximum allowable pressure at any standpipe outlet hose connection to prevent hose control problems for firefighters?
- 150 psi
- 175 psi
- 200 psi (Correct answer)
- 250 psi
Correct answer: 200 psi
NFPA 14 limits standpipe hose connection pressure to a maximum of 175 psi without a pressure-reducing device; NYC requires the outlet not exceed 175 psi, and many references cap unregulated flow at 200 psi—but the standard working maximum without PRVs is 175 psi per NFPA 14.
Question 3: Which water supply source is considered the primary supply for standpipe systems in most New York City high-rise buildings?
- Gravity tank on the roof
- City water main connection
- Fire pump drawing from a suction tank (Correct answer)
- Pressure tank in the basement
Correct answer: Fire pump drawing from a suction tank
In most NYC high-rise standpipe systems, a fire pump drawing from a dedicated suction tank provides the primary pressurized water supply to meet flow and pressure demands.
Question 4: What minimum flow rate must a Class I standpipe system be capable of delivering at the two most hydraulically remote 2½-inch outlets simultaneously?
- 250 gpm per outlet
- 500 gpm total (Correct answer)
- 350 gpm total
- 750 gpm total
Correct answer: 500 gpm total
NFPA 14 requires Class I and Class III standpipe systems to supply a minimum of 500 gpm total (250 gpm per outlet) to the two most remote 2½-inch hose connections simultaneously.
Question 5: A gravity tank used as a water supply for a standpipe system must have its bottom elevation at least how many feet above the highest hose outlet it serves?
- 15 feet
- 20 feet
- 25 feet (Correct answer)
- 35 feet
Correct answer: 25 feet
New York City Building Code and NFPA 14 require the bottom of a gravity tank to be at least 25 feet above the highest standpipe outlet it supplies to develop sufficient static pressure.
Question 6: What is the purpose of a pressure-maintenance (jockey) pump in a standpipe water supply system?
- To boost pressure during active firefighting
- To compensate for minor system leaks and maintain system pressure without starting the main fire pump (Correct answer)
- To fill the suction tank automatically
- To test standpipe pressure weekly
Correct answer: To compensate for minor system leaks and maintain system pressure without starting the main fire pump
A jockey (pressure-maintenance) pump is a small pump that cycles on and off to maintain standpipe system pressure, compensating for minor leakage without activating the larger main fire pump.
Question 7: Under FDNY regulations, what is the minimum capacity of a suction tank that serves as the sole water supply for a standpipe system in a building over 100 feet tall?
- 3,500 gallons
- 5,000 gallons
- 7,500 gallons (Correct answer)
- 10,000 gallons
Correct answer: 7,500 gallons
FDNY and NYC Building Code require a minimum suction tank capacity of 7,500 gallons to provide an adequate reserve water supply for standpipe operations in tall buildings.
S-13 Water Supply and Pressure Requirements 1
What is the minimum residual pressure required at the highest outlet of a Class I or Class III standpipe system in New York City during operation?