Chapter 5 Portable Extinguishers Flashcards
Extinguishers
- one of the most common fire protection appliances in use today - Fixed facilites and appartus - Excellent in incipient fires
NFPA 10
Standard for Portable Fire Extinguishers
NFPA 1901 Requires that pumping apparatus have what for extinguishers
-minimum dry chem 80B:C -(CO2) Carbon Dioxide 10B:C -2 1/2 gal water extinguisher
ABC
2 1/2-30lbs Reach 5-20’ 8-25 seconds
Pump tank
1 1/2-5gallons Reach 30-40’ 45 seconds to 3 minutes A fires only
Stored-Pressure water extinguishers
(air-pressurized water) “APW” small class a fires, hot spots, chimney flue fires -Compressed air or Nitrogen
AFFF
Aqueous Film Forming Foam A&B fires Compressed Air or Nitrogen Suppresing vapors by rain down or deflect off object -Different than APW in two ways - Specific amount of AFFF concentrate - Air aspirating nozzle Not effective on flamable liquids that are water-soluble(polar solvents) Alcohol & Acetone
Halon Extinguishers
- Two most common - Halon 1211 ( Bromochlorodifluoromethane) - Halon 1301 ( Bromotrifluoromethane)
Carbon Dioxide Computer labs
(CO2) B & C fires ( displaces O2 & Smothers) less than 15’. - Handheld & Wheeled units, Discharge in gas, Limited reach, Stored under its own pressure as liquified gas. -wheeled units most common @ airports & industrial facilites
Dry Chemical
ABC or BC Fires *Most common in use today -Two types (BC/ABC) -Common used dry chemicals are Sodium Bicarbonate, Potassium Bicarb, Urea Potassium Bicarbonate, Potassium chloride, Monommonium Phosphate - Corrosive to metals
Dry Powder
Class D fires only
Handheld Units
-Two basic designs - Stored- Pressure, simiular to APW with constant pressure about 200psi - Cartridge- operated, plunger pushed to energize Nitrogen or carbon Dioxide
Extinguisher Rating System
A triangle green, ordinary combustibles
B box red, flammable liquids
C circle Blue, Electrical
D Star Yellow, Combustible metals
Extgusiher rating systems for class A,B,C,D
- Class A - 1A-40A water - 1A=1 1/4 gallons, 2A= 2.5 gallons or twice of 1A
- Class B - 1B-640B - Square foot of flammable liquid that a nonexpert could put out.
- Class C No fire extinguishing
- Class D ratings vary with type of combustible metals being tested Reactions between the metals and agent Toxicity of the agent Toxicity of the fumes produced & the products of combustion. Time to allow metal to burn out without fire suppression efforts versus time to extinguish
Mulitple markings on extinguishers
Most common are A-B-C, A-B & B-C
Two systems of labeling portable Extinguishers
- Geometric shape , triagle, box, circle, star
- Pictographs
Inspecting extinguisher immediately before use
- External condition, no apparent damage - Hose/Nozzle, in place - Weight- Feels as though it contains agent - Pressure gage (if available), in operable range
Use of Extinguisher
- Select approprite size & type - approach from windward side (wind at back) - If not extinguished after full extinguisher, back of & reasses. - Lay empty extinguishers on their side
Inspecting Extinguishers
- Inspect regularly to ensure accessible & operable, designated loacation, & not been activated and tampered with. - Servicing is the responsibility of the property owner or building occupant.
During Inspections
-Check for proper loaction, Accessible & inspection tag date. - Check discharge nozzle or horn, obstuctions, cracks, dirt or grease - Check shell for damage, lock pins, tamper seals, full of agent & pressure, weight - Instructions of nameplate are legible - If found deficant in weight by 10% remove from service.
3 important factors that determine the value of extinguishers?
- Serviceability - Accessibility - User’s ability to operate it
Inverting type Extinguishers
Stopped in 1969 29CFR1910-157 Sept 12,1980 needed to remove all inverted soft solder, revited by , Jan 1982
