Fire Extinguisher

NFPA 10 Fire Extinguisher Guide: Coverage, Testing & Care

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NFPA 10 Fire Extinguishers — Student Guide with Coach Panel & Verbatim Checklist

NFPA 10 Fire Extinguishers — Student Guide (with Verbatim Checklist)

Interactive learning aids + the full Annex I Table I.1(a) text intact. Coach notes are optional; the checklist is authoritative.

On this page
  1. Quick workflow
  2. Mini glossary
  3. Coverage per extinguisher (E.3.5)
  4. Quantity helper (with steps)
  5. Maintenance & hydrostatic testing
  6. Mechanical parts checklist — verbatim
  7. Worked scenarios
  8. Notes & memory aids

1) Quick workflow

  1. Identify hazard: Light / Ordinary / Extra.Hazard groupsLight = low fuel load; Ordinary = moderate fuels; Extra = high fuels/rapid growth.
  2. Choose Class A rating (2-A, 4-A, 10-A…).Class A ratings“A” = ordinary combustibles; the number scales the tested fire size & capability.
  3. Find coverage per unit (Table E.3.5).
  4. Count units = area ÷ coverage (round up) or use the helper.
  5. Pick agent & shell; then apply service intervals.
  6. Inspect mechanics with the verbatim checklist.

2) Mini glossary

Travel distanceTravel distanceWalking distance to reach an extinguisher. Placement rules cap this.Hydrostatic testHydrostatic testPressure test of the cylinder to verify structural integrity after years of service.Cartridge-operatedCartridge-operatedUses a separate gas cartridge; requires annual internal exam.AFFF / FFFPAFFF / FFFPFoam agents for flammable liquids; liquid charge type: replace agent every 3 years; teardown typically done then.

3) Coverage — maximum area per extinguisher Table E.3.5

Class A rating (label) Light-Hazard
(ft² / m²)
Ordinary-Hazard
(ft² / m²)
Extra-Hazard
(ft² / m²)
1-A6,000 (557)3,000 (279)
2-A9,000 (836)4,500 (418)
4-A11,250 (1,045)6,000 (557)4,000 (372)
6-A11,250 (1,045)9,000 (836)6,000 (557)
10-A11,250 (1,045)11,250 (1,045)10,000 (929)
20-A11,250 (1,045)11,250 (1,045)11,250 (1,045)
30-A11,250 (1,045)11,250 (1,045)11,250 (1,045)
40-A11,250 (1,045)11,250 (1,045)11,250 (1,045)
11,250 ft² (≈1,045 m²) is a practical limit.

4) Quantity — helper (with “show steps”)

This mirrors Table E.3.6 by computing ceil(Area ÷ Coverage).

Enter area, choose hazard and rating, then click Calculate.

    Common slips

    • Picking a rating with no coverage for your hazard (e.g., 2-A for Extra-Hazard).
    • Forgetting to round up when the division isn’t whole.
    • Stopping after the count—remember travel distance, placement, and mounting heights.

    5) Maintenance & hydrostatic testing — merged snapshot

    Extinguisher type Internal exam
    (years)
    Hydro test
    (years)
    Notes
    Stored-pressure water55
    Water mist / loaded stream / antifreeze1–55Loaded stream & antifreeze often treated at 1-yr internal; confirm with your edition/AHJ.
    Wetting agent15
    AFFF35Liquid-charge: replace agent every 3 yrs; teardown then.
    FFFP35As above.
    Dry chemical — stored-pressure (mild steel / brass / aluminum)612Nonrechargeable: remove at 12 yrs (no 6-yr internal).
    Dry chemical — stored-pressure (stainless)55
    Dry chemical — cartridge/cylinder-operated1*12Annual internal.
    Dry powder — stored-pressure612
    Dry powder — cartridge/cylinder-operated1*12Annual internal.
    Carbon dioxide (CO₂)55
    Wet chemical55
    Halogenated agents612Nonrechargeable: remove at 12 yrs; return agent for reclaim.
    Pump-tank water / pump-tank (calcium chloride)1Follow manufacturer/AHJ for hydro interval.
    Consolidated from your captured NFPA 10 tables (maintenance + hydro).

    * Cartridge/cylinder-operated dry chemical & dry powder: internal exam annually.

    6) Mechanical parts maintenance checklist — verbatim (Annex I, Table I.1(a))

    Authoritative text (no edits)

    Cylinder/Shell — Corrective Action

    1. Hydrostatic test date or date of manufacture — Retest, if needed
    2. Corrosion — Conduct hydrostatic test and refinish, or condemn
    3. Mechanical damage (denting or abrasion) — Conduct hydrostatic test and refinish, or condemn
    4. Paint condition — Refinish
    5. Presence of repairs (welding, soldering, brazing, etc.) — Condemn
    6. Damaged threads (corroded, crossthreaded, or worn) — Condemn
    7. Broken hanger attachment, carrying handle lug — Condemn
    8. Sealing surface damage (nicks or corrosion) — Condemn

    Nameplate — Corrective Action

    1. Illegible wording — Clean or replace (Note: Only labels without a listing mark can be replaced.)
    2. Corrosion or loose plate — Inspect shell under plate and reattach plate

    Nozzle or Horn — Corrective Action

    1. Deformed, damaged, or cracked — Replace
    2. Blocked openings — Clean
    3. Damaged threads (corroded, crossthreaded, or worn) — Replace
    4. Aged (brittle) — Replace

    Hose Assembly — Corrective Action

    1. Damaged (cut, cracked, or worn) — Replace
    2. Damaged couplings or swivel joint (cracked or corroded) — Replace
    3. Damaged threads (corroded, crossthreaded, or worn) — Replace
    4. Inner tube cut at couplings — Replace or consult manufacturer
    5. Electrically nonconductive between couplings (CO₂ hose only) — Replace
    6. Hose obstruction — Remove obstruction or replace
    7. Hydrostatic test date — Retest if needed

    Pull/Ring Pin — Corrective Action

    1. Damaged (bent, corroded, or binding) — Replace
    2. Missing — Replace

    Gauge or Pressure-Indicating Device — Corrective Action

    1. Immovable, jammed, or missing pointer (pressure test) — Depressurize and replace gauge
    2. Missing, deformed, or broken crystal — Depressurize and replace gauge
    3. Illegible or faded dial — Depressurize and replace gauge
    4. Corrosion — Depressurize and check calibration, clean and refinish, or replace gauge
    5. Dented case or crystal retainer — Depressurize and check calibration, or replace gauge
    6. Immovable or corroded pressure-indicating stem (nongauge type) — Depressurize and discard shell
    7. Verify gauge compatibility — Depressurize and replace

    Shell or Cylinder Valve — Corrective Action

    1. Corroded, damaged, or jammed lever, handle, spring, stem, or fastener joint — Depressurize, check freedom of movement, and repair or replace
    2. Damaged outlet threads (corroded, crossthreaded, or worn) — Depressurize and replace

    Nozzle Shutoff Valve — Corrective Action

    1. Corroded, damaged, jammed, or binding lever, spring, stem, or fastener joint — Repair and lubricate, or replace
    2. Plugged, deformed, or corroded nozzle tip or discharge passage — Clean or replace

    Puncture Mechanism — Corrective Action

    1. Damaged, jammed, or binding puncture lever, stem, or fastener joint — Replace
    2. Dull or damaged cutting or puncture pin — Replace

    Expellant/Gas Cartridge — Corrective Action

    1. Corrosion — Replace with correct expellant gas cartridge
    2. Damaged seal disc (injured, cut, or corroded) — Replace with correct expellant gas cartridge
    3. Damaged threads (corroded, crossthreaded, or worn) — Replace with correct expellant gas cartridge
    4. Illegible weight markings — Replace with correct expellant gas cartridge
    5. Improper gas cartridge — Replace with correct expellant gas cartridge
    6. Improper cartridge seal — Replace with correct expellant gas cartridge

    Gas Cylinders — Corrective Action

    1. Hydrostatic test date or date of manufacture — Retest if needed
    2. Corrosion — Conduct hydrostatic test and refinish, or discard
    3. Paint condition — Refinish
    4. Presence of repairs (welding, soldering, brazing, etc.) — Condemn
    5. Damaged threads (corroded, crossthreaded, or worn) — Condemn

    Fill Cap — Corrective Action

    1. Corroded, cracked, or broken — Replace
    2. Damaged threads (corroded, crossthreaded, or worn) — Replace
    3. Sealing surface damage (nicked, deformed, or corroded) — Clean, repair, and leak test, or replace
    4. Obstructed vent hole or slot — Clean

    Nonrechargeable Shell/Cylinder — Corrective Action

    1. Corrosion — Depressurize and discard
    2. Damaged seal disc (injured, cut, or corroded) — Depressurize and discard
    3. Illegible weight or date markings — Depressurize and discard

    Carriage and Wheels — Corrective Action

    1. Corroded, bent, or broken carriage — Repair or replace
    2. Damaged wheel (buckled or broken spoke, bent rim or axle, loose tire, low pressure, jammed bearing) — Clean, repair, and lubricate, or replace

    Carrying Handle — Corrective Action

    1. Broken handle — Condemn cylinder or consult manufacturer regarding repair
    2. Broken handle — Replace
    3. Corroded, jammed, or worn fastener — Clean or replace

    Tamper Seals or Indicators — Corrective Action

    1. Broken or missing — Check Table I.1(b) for specific action
    2. Fill cap indicator corroded or inoperative — Repair, clean, or replace
    3. Fill cap indicator operated — Depressurize unit, check content, refill

    Hand Pump — Corrective Action

    1. Corroded, jammed, or damaged pump — Repair and lubricate, or replace
    2. Improper adjustment of packing nut — Adjust

    Pressurizing Valve — Corrective Action

    1. Leaking seals — Depressurize and replace valve or core

    Gasket and “O” Ring Seals — Corrective Action

    1. Damaged (cut, cracked, or worn) — Replace and lubricate
    2. Missing — Replace and lubricate
    3. Aged or weathered (compression set, brittle, cracked) — Replace and lubricate

    Brackets and Hangers — Corrective Action

    1. Corroded, worn, or bent — Repair and refinish, or replace
    2. Loose or binding fit — Adjust fit or replace
    3. Worn, loose, corroded, or missing screw or bolt — Tighten or replace
    4. Worn bushing, webbing, or grommet — Replace
    5. Improper type — Replace

    Gas Tube and Siphon or Pickup Tube — Corrective Action

    1. Corroded, dented, cracked, or broken — Replace
    2. Blocked tube or openings in tube — Clean or replace

    Safety Relief Device — Corrective Action

    1. Corroded or damaged — Depressurize and replace
    2. Broken, operated, or plugged — Depressurize and replace

    Pressure Regulators — Corrective Action

    1. External condition: damaged or corroded — If damaged, replace regulator; if corroded, clean regulator or replace
    2. Pressure relief (corroded, plugged, dented, leaking, broken, or missing) — Disconnect regulator from pressure source, replace pressure relief, or replace regulator
    3. Protective bonnet relief hole (tape missing or seal wire broken or missing) — Replace regulator
    4. Adjusting screw (lock pin missing) — Replace regulator
    Coach Notes — Student summary (non-normative)

    This is a learning aid. The authoritative text above governs.

    • Any welded/brazed cylinder repair or damaged threads/lugs → Condemn.
    • Cartridge-operated units: verify cartridges; replace if any doubt.
    • Gauges with jammed pointers/broken crystal/illegible dials → Depressurize & replace.
    • Regulators with missing seal wire or lock pin → Replace regulator.

    7) Worked scenarios

    Office floor (Light-Hazard), 90,000 ft², 2-A water

    1. Coverage: 2-A Light → 6,000 ft²/unit.
    2. Math: 90,000 ÷ 6,000 = 15 → 15 units.
    3. Intervals: Stored-pressure water → internal 5 yrs, hydro 5 yrs.

    Manufacturing bay (Extra-Hazard), 100,000 ft², 4-A ABC dry chem

    1. Coverage: 4-A Extra → 4,000 ft²/unit.
    2. Math: 100,000 ÷ 4,000 = 25 → 25 units.
    3. Intervals: DC stored-pressure → internal 6 yrs, hydro 12 yrs (nonrechargeable: remove at 12 yrs).

    8) Notes & memory aids

    • Round up unit counts; then confirm travel distance & mounting.
    • Annual internal for cartridge/cylinder-operated DC/DP.
    • Foam at 3 years (liquid-charge AFFF/FFFP): replace agent; do internal then.
    • Log hydro dates, internal exams, agent replacements, and all corrective actions.

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