SCBA Flashcards
“Hey Recruit! What is that thing with the tank on your back?”
“Sir, Recruit ____, it is an open-circuit, pressure demand, positive pressure, fully automatic self-contained breathing apparatus.”
Open circuit
exhales to the environment through the facepiece mounted regulator
pressure demand
demand valve in regulator opens upon inhalation
positive pressure
maintains a slightly higher pressure inside the facepiece compared to the surround air pressure
What is the NFPA for SCBA’s?
d. NFPA 1981: Standard on Open-Circuit, Self-contained Breathing Apparatus for Fire Fighters
How long can you be on air?
i. Designed to provide maximum mobility with 30-60min of air and respiratory protection for the user
ii. Realistically provides 15-45min of actual work time
Factors affecting air time (user)
i. Physical activity of wearer
ii. Physical fitness of user
iii. Emotional factors affecting breathing rate
iv. Experience (comfort level and training) using device
Factors affecting air time (equipment)
v. Full cylinder or no
vi. Loose or improperly fitting facepiece
vii. SCBA condition
What hazardous conditions warrant SCBAs?
Smoke Heat Toxic gases Irritant particulates Deficient oxygen Potential for rapid or explosive combustion
Hazardous gases
Carbon Monoxide Hydrogen Chloride Hydrogen Cyanide Nitrous Oxides Phosgene
Carbon Monoxide
- Colorless, odorless; product of incomplete combustion; is present at every fire, including during overhaul stage
Hydrogen Chloride
- Colorless, pungent smelling gas; eye and lung irritant; present whenever there is burning or smoking chlorine based plastics, including during overhaul stage
Hydrogen Cyanide
- Colorless gas with an almond odor, a product of heated or burning wool, nylon, polyurethane foam, rubber and paper; often found during clothing/rug store fires, including during overhaul stage
Nitrous Oxides
- Reddish brown gas that is a pulmonary irritant present in fires where wallpaper or lacquer have been involved including during overhaul stage.
Phosgene
- Colorless, tasteless gas with a disagreeable odor; produced when refrigerants (like Freon) are exposed to flame; may be present in all structure/vehicle/refrigeration equipment fires including during overhaul stage.
What are ways teams can stay in communication?
i. Visual
ii. Audible
iii. Physical
iv. Safety Rope
v. Electronic
vi. Other
b. All personnel entering should have SCBA on and in use prior to entering:
i. Known hazardous atmospheres
ii. Suspected hazardous atmospheres
iii. Those which may become hazardous
iv. Confined or below grade spaces per NFPA 1500
v. Overhaul ops
NFPA 1500
Standard on Fire Department Occupational Safety and Health Program
NFPA 1404
Standard for Fire Service Respiratory Protection Training
SCBA’s do not protect from
i. Excessive heat
ii. Absorbed toxins
iii. Flashovers, backdrafts, smoke explosions, or other rapidly changing fire events
IDLH
Immediately dangerous to life and health
NFPA 1404 and TFD policy is to leave IDLH prior to ____?
low pressure alarm sounding
If Vibralert or HUD indicates low pressure….
Notify captain,
get partner
get out!
SCOTT 4.5 SCBA
a. Training use only
b. Wire frame
c. Manual PAL
d. Lacking safety features
SCOTT 50 SCBA
a. Lots of versions some with PAL, integrated PASS, bell assembly, HUD, CBRN indicators, EBSS, LEDs on hose, quick disconnects
EBSS
emergency breathing support system
SCOTT 75 SCBA
a. Latest and greatest SCBA
b. Has integrated handles, drag handles, modified control console, dual manifold EBSS umbilical, quick disconnect regulator, RIC/UAC connecter, HUD on regulator
HUD lights meaning
Double green, 100%, single green, 75%, yellow 50%, red fast flash 25%.
Cylinder types
Fiberglass
Kevlar
Carbon fiber
Fiberglass cylinders
use for drilling only
Kevlar cylinders
yellow or off white
a. Aluminum inner shell with a full wrap Kevlar/epoxy resin with clear coat finish, reinforced ends.
b. 4500psi max
c. 30 minute have 45 cu.ft.
d. 60 minute have 87 cu.ft and weight 20.4lbs
e. With pack, that’s 29lbs
f. Hydrostatically tested every 3 years
Carbon fiber
clear coat, greyish
a. Aluminum inner shell overwrapped with a carbon epoxy resin, reinforced ends.
b. 4500psi max
c. 30 minute have 45 cu.ft.
d. 60 minute have 87 cu.ft and weight 18.9lbs
e. With pack, that’s 27.5lbs
f. Hydrostatically tested every 5 years
parts of a cylinder
a. Rubber bumper: protects end
b. Cylinder gauge
c. Cylinder hanger: connects to frame
d. Over pressurization disk:
safety release valve
e. Cylinder valve: Push to turn
Pressure reducer and high pressure hose assembly details
i. This is where the SCBA’s brain is. All automatic
ii. Primary pressure reducer reduces to 100psi
iii. Secondary reducer reduces to 150 psi
iv. Automatic transfer valve
v. Check valve
vi. Re-seatable overpressure relief valve that trips at 225psi
Face mounted regulartor assembly
- Diaphragm
- Exhalation valve assembly
- Vibralert
- Demand piston
- Donning switch
- Purge valve
Facepiece stats
- AV2000 –recruits only
- AV3000 – used in the field, has better visibility
- Green, small; black, large; red, XL
- Meets NIOSH/MSHA certification and NFPA 1981: 2013
LPM for facepiece
iii. Delivers 160LPM
1. Peak 500LPM
2. Sustained up to 400LPM
Vibralert trips at ____?
~1100psi or 25% total volume (SCOTT 50 and 75 have LED alerts as well)
PASS stats and details
- Personal Alert Safety System
- Formerly known as PAL on old SCOTTs (manual activation)
- Normally integrated to turn on with air activation
- Sometimes called PAK-ALERT SE on SCOTT 75
- Has movement sensor in base
- Can be turned on manually by remote gauge control console
- Prealert after 20sec of no motion
- Full alert after another 12
Path of air molecule through SCBA
a. Cylinder valve assembly
b. High pressure hose
c. Pressure reducer assembly
d. Primary pressure reducer
e. Low pressure hose
f. Regulator into mask
If the pressure reducer fails open
a. Cylinder valve assembly
b. High pressure hose
c. Pressure reducer assembly
d. Primary pressure reducer without being reduced
e. Reseatable overpressure relief valve. Allows air to flow at 225psi to mask and excess out the valve
f. Low pressure hose
g. Regulator into mask
Inspecting SCBA
a. Wear and tear
b. Check reset
c. Open cylinder and listen for PASS chirps
d. Test motion sensor reset
e. Test button reset
f. Test full alarm
Control sensor module lights
a. Open cylinder = bright light then flash green
b. Normal operations = flash green
c. Respirator low (1/4th tank) = flash orange (alternating)
d. Low battery while one = flash orange once every two seconds
e. Shut down = lights off
f. Press RESET while unit off for a battery test
i. Flash green = Good
ii. Flash red = Low
g. Manual alarm while unit off = flash green then full alarm flash red
h. PASS prealarm = flash alternatingly
i. PASS full alarm = flash red simultaneously
When do you inspect your SCBA
a. Inspect before each shift
b. After each use
c. On the 15th of the month
General cleaning
- Remove debris
- Spray clean
- Do not bleach or submerge regulator or use alcohol products
- Shake then towel dry
- Change cylinder and blow out using purge valve
- To sanitize, spray with multi wash solution then follow the above steps.
Battery replacement
- 1st gen: single 9v
- 2nd gen: 2 AA
- 3rd gen: 2 9v
- SCOTT 75 Integrated PASS: 6 AA
iii. Contact maintenance for other repairs
iv. Contact supervisor for replacement
Describe the path of a air molecule through SCBA
Cylinder, cylinder Valve assembly (CVA), HP hose, Pressure reducer assembly, primary pressure reducer to 100 psi, bypass over-pressurization relief vale, LP hose, mask mounted regulator
