FE Recharging & Hydrostatic Testing Flashcards

Which agent must be used when recharging a Purple-K (PKP) dry chemical extinguisher?

Answer: Purple-K potassium bicarbonate dry chemical only

Purple-K extinguishers must be recharged with Purple-K (potassium bicarbonate) only — mixing dry chemical agents is prohibited.

What is the correct pressure range for charging a standard ABC stored-pressure dry chemical extinguisher?

Answer: 125–175 psi

Standard ABC stored-pressure dry chemical extinguishers are typically charged to 125–175 psi with dry nitrogen as specified by the manufacturer.

Why must dry nitrogen (not CO2) be used to pressurize dry chemical stored-pressure extinguishers?

Answer: CO2 can react with the dry chemical agent and cause caking or loss of pressure

CO2 can react with moisture and dry chemical agents, potentially causing caking or pressure loss, so dry nitrogen is specified.

After recharging a wet chemical (Class K) extinguisher, what must the technician verify before returning it to service?

Answer: That agent level, pressure, and nozzle condition all meet manufacturer specifications

Before returning a recharged wet chemical extinguisher to service, the technician must verify correct agent fill level, proper pressure, and clean nozzle condition.

What is the required hydrostatic test interval for a stored-pressure water-type fire extinguisher?

Answer: 5 years

Stored-pressure water-type extinguishers must be hydrostatically tested every 5 years per NFPA 10.

When is it acceptable to top off (add a small amount of agent) to a partially discharged dry chemical extinguisher instead of fully recharging it?

Answer: Never — partial discharge requires complete recharge

NFPA 10 does not permit topping off; any partial or full discharge requires a complete recharge with fresh agent.