F89 Fire Protection Systems 4 — Questions and Answers
Question 1: What is the minimum water supply duration required for a high-rise sprinkler system under NFPA 13?
- 30 minutes
- 60 minutes (Correct answer)
- 90 minutes
- 120 minutes
Correct answer: 60 minutes
NFPA 13 requires a minimum water supply duration of 60 minutes for high-rise sprinkler systems.
Question 2: A dry-pipe sprinkler system is most appropriate for which of the following environments?
- A heated office building lobby
- An unheated parking garage in a cold climate (Correct answer)
- A kitchen with high grease exposure
- A server room with sensitive electronics
Correct answer: An unheated parking garage in a cold climate
Dry-pipe systems use pressurized air instead of water, preventing pipe freezing in unheated spaces.
Question 3: Which component in a wet-pipe sprinkler system prevents water from flowing backward into the public water supply?
- Pressure reducing valve
- Backflow preventer (Correct answer)
- Check valve at the riser
- OS&Y gate valve
Correct answer: Backflow preventer
A backflow preventer stops contaminated water from re-entering the potable water supply.
Question 4: In a fire alarm system, what does a 'supervisory signal' indicate?
- A fire has been detected
- A system component is impaired but no fire exists (Correct answer)
- Evacuation has been initiated
- A trouble condition in the notification appliance circuit
Correct answer: A system component is impaired but no fire exists
A supervisory signal alerts personnel to an off-normal condition that could affect system performance, such as a closed sprinkler valve.
Question 5: When a sprinkler system control valve is closed for maintenance, the Fire and Life Safety Director must:
- Notify only the building owner
- Place the system in test mode only
- Implement a fire watch and notify the AHJ and fire department (Correct answer)
- Post a sign on the valve and resume normal operations
Correct answer: Implement a fire watch and notify the AHJ and fire department
Closing a sprinkler control valve impairs fire protection, requiring an immediate fire watch and notification to the AHJ and fire department.
Question 6: A pre-action sprinkler system requires which TWO conditions before water is released?
- High heat AND low pressure
- Smoke detection AND sprinkler head activation (Correct answer)
- Manual pull station AND alarm panel acknowledgment
- Smoke detection AND water pressure drop
Correct answer: Smoke detection AND sprinkler head activation
Pre-action systems require both detection device activation and sprinkler head fusing before water discharges, providing double-interlock protection.
Question 7: The fire pump starts automatically when system pressure drops to what condition?
- When a sprinkler head opens and pressure falls below the pump churn pressure (Correct answer)
- Whenever the jockey pump activates
- When the main drain valve is opened
- Only upon manual activation by the FLS Director
Correct answer: When a sprinkler head opens and pressure falls below the pump churn pressure
The fire pump starts automatically when system pressure drops below its cut-in pressure, typically triggered by sprinkler head opening.
F89 Fire Protection Systems 4
What is the minimum water supply duration required for a high-rise sprinkler system under NFPA 13?