Systems Inspection, Testing and Servicing

FDNY S81 Dry Chemical Fire Extinguishing Systems Inspection, Testing and Servicing Principles (Citywide) Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

1. The primary purpose of a dry chemical fire extinguishing system is to:

• Cool the fire
• Smother the fire
• Interrupt the chemical reaction of the fire
• Absorb the heat from the fire

Rationale: Dry chemical systems work by interrupting the chemical

chain reaction necessary for combustion.

• NFPA 17 governs which type of fire extinguishing systems?
• Water-based sprinkler systems
• Dry chemical fire extinguishing systems
• Foam suppression systems 1 / 4

• Carbon dioxide systems

Rationale: NFPA 17 specifically addresses the installation,

maintenance, inspection, and testing of dry chemical extinguishing systems.

• Which type of fire is most effectively suppressed by dry chemical

agents?

• Class A only
• Class B only
• Class B and C
• Class A, B, and D

Rationale: Dry chemical agents are effective for flammable liquid

(Class B) and energized electrical (Class C) fires.

• The minimum frequency for an internal inspection of dry chemical

extinguishing cylinders is:

• Monthly
• Every 3 months
• Annually
• Every 5 years

Rationale: NFPA 17 requires annual internal inspection to ensure

integrity and operability of the cylinder.

• What is the primary hazard associated with discharging a dry chemical

system in a confined space?

• Water damage 2 / 4

• Electrical shock
• Reduced visibility and inhalation risk
• Overheating of the agent

Rationale: Dry chemical discharge produces dense clouds that can

impair breathing and visibility.

• Which color coding is generally used for dry chemical extinguishing

systems?

• Blue
• Green
• Red
• Purple

Rationale: NFPA standards often use purple to identify dry chemical

extinguishing systems.

• The most common dry chemical used in commercial fire extinguishing

systems is:

• Sodium bicarbonate
• Sodium chloride
• Monoammonium phosphate
• Potassium carbonate

Rationale: Monoammonium phosphate is effective on Class A, B, and

C fires and is widely used in commercial systems.

8. A hydrostatic test of a dry chemical cylinder should be performed:

• Every 6 months 3 / 4

• Every 5 years
• Every 10 years
• Only when damaged

Rationale: Hydrostatic testing ensures cylinder integrity under

pressure and is required every 5 years per NFPA 17.

• What is the first step when inspecting a dry chemical system?
• Verify system pressure and agent level
• Test discharge nozzles
• Check alarm panel functionality
• Conduct a hydrostatic test

Rationale: Proper system function begins with confirming that the

agent is at the correct level and pressure.

10. A common sign of dry chemical caking in a cylinder is:

• Color fading
• Pressure gauge reading too high
• Difficulty in agent flow during discharge
• Corrosion on the cylinder exterior

Rationale: Caking prevents proper flow, reducing the effectiveness of

the system.

• When servicing a dry chemical system, what safety equipment is

essential?

• Fireproof clothing only
• Earplugs
• / 4