FE Inspection & Maintenance Procedures 3 — Questions and Answers
Question 1: According to NFPA 10, what is the minimum pressure shown on a gauge for a stored-pressure extinguisher to be considered acceptable during a visual inspection?
- Any reading within the green zone on the gauge (Correct answer)
- At least 100 psi regardless of gauge markings
- Exactly at the manufacturer's rated fill pressure
- No minimum; any visible needle position is acceptable
Correct answer: Any reading within the green zone on the gauge
NFPA 10 requires the pressure gauge needle to be in the manufacturer's specified green (operable) zone for the unit to remain in service.
Question 2: When must the internal inspection (partial disassembly) of a stored-pressure water or AFFF extinguisher be performed?
- Every 3 years from the date of manufacture
- Every 5 years from the date of manufacture or last hydrostatic test (Correct answer)
- Every year as part of annual maintenance
- Only when the extinguisher has been discharged
Correct answer: Every 5 years from the date of manufacture or last hydrostatic test
NFPA 10 requires an internal examination of water-based stored-pressure extinguishers every 5 years from manufacture or last hydrostatic test.
Question 3: A technician is inspecting an extinguisher and finds the tamper seal is broken but the pull pin is still installed. What should be done?
- Replace only the tamper seal and return to service after noting it on the tag
- Perform a full annual maintenance to verify the unit has not been tampered with (Correct answer)
- Condemn the extinguisher immediately
- Add a new tamper seal and consider the inspection complete
Correct answer: Perform a full annual maintenance to verify the unit has not been tampered with
A broken tamper seal indicates possible unauthorized access; a full annual maintenance must be performed to confirm the extinguisher's operational readiness.
Question 4: What is the purpose of weighing a self-expelling CO2 cartridge during maintenance of a cartridge-operated extinguisher?
- To verify it meets the minimum weight required for the hazard class
- To detect agent leakage that would otherwise be invisible (Correct answer)
- To confirm the CO2 is within the shelf-life date stamped on the cartridge
- To check whether the cartridge is overfilled beyond safe limits
Correct answer: To detect agent leakage that would otherwise be invisible
CO2 gas is odorless and colorless, so weighing is the only practical way to detect leakage from a CO2 expellant cartridge.
Question 5: During maintenance of a wheeled fire extinguisher, NFPA 10 requires the hose and nozzle assembly to be inspected for what condition in particular?
- Hose length conforming to manufacturer's specifications
- Freedom from cracks, cuts, abrasions, and obstructions (Correct answer)
- Color coding matching the agent type
- Pressure test record attached to the hose coupling
Correct answer: Freedom from cracks, cuts, abrasions, and obstructions
The hose must be checked for cracks, cuts, abrasions, and any obstructions that would impede flow or cause burst failure during use.
Question 6: Which action is specifically prohibited when reassembling a dry chemical extinguisher after maintenance?
- Using Teflon tape on valve threads
- Lubricating O-rings with petroleum-based grease (Correct answer)
- Tightening the valve stem to manufacturer torque specification
- Purging moisture with dry nitrogen before closing
Correct answer: Lubricating O-rings with petroleum-based grease
Petroleum-based lubricants degrade rubber O-rings and seals; only manufacturer-approved silicone or compatible lubricants may be used.
Question 7: A stored-pressure halon 1211 extinguisher is found to have lost weight. What is the correct service action?
- Top off with additional halon 1211 from a recovery cylinder
- Send to a certified halon service facility for recharging (Correct answer)
- Condemn the unit because halon is no longer producible
- Replace the lost weight with HFC-227ea as a drop-in substitute
Correct answer: Send to a certified halon service facility for recharging
Halon is a controlled substance and recharging must be performed at an EPA-compliant facility using recovered/recycled halon; it cannot be substituted with another agent.
FE Inspection & Maintenance Procedures 3
According to NFPA 10, what is the minimum pressure shown on a gauge for a stored-pressure extinguisher to be considered acceptable during a visual inspection?