17-03 Positive Pressure Attack Flashcards
What SOG is this SOG an extension of?
SOG 17-01 Ventilation
What does PPA create?
a unidirectional flow path
What does PPA remove from a structure? (3)
- smoke
- heat
- other products of combustion
What does PPA intend to achieve? (3)
- tenable atmosphere
- improve speed of access to fire location and/ or
- location of patients
What can be done to cool increase effectiveness and safety of PPA? (2)
- using transitional attack
2. have interior crews apply water into upper portions of ceiling area while proceedig to fire room
What is Backflow?
pressurized air coming out at inlet point
How would one know if building is appropriate for PPA?
if no heavy smoke/ fire exhausting out of inlet point.
What can be done to
f
What can be done to make a building suitable for PPA? (2)
- larger/ additional exhausts need to be created
2. vent fan needs to be throttlesd down
What is Transitional Attack?
offensive fire attack initiated by exterior indirect handline operation into fire compartment.
What does Transitional Attack achieve?
initiate cooling while transitioning into interior direct fire attack in coordination w/ ventilation
What are considerations for PPA? (7)
- 360 completed
- flowpaths determined
- confirm VES ops complete and protected occupants
- fire location determined
- fire does not involve structure
- minimum 2 crews on scene
- exhaust locations have been determined
Where are fans placed for PPA? (2)
- at point of entry from unburned side?
2. 2m back from entry point
Why place fan 2m back from entry point?
- create “cone” efect around door
2. allow access for crews
How long is PPA used for?
brief durations, not meant for long term
Where are personnel when PPA commenced?
outside of structure
How can PPA be judged as to effectiveness? (3)
- if improves atmosphere- continue with it
- makes no changes- review all aspects and re-position
- worsens condition- discontinue
What are requirements prior to PPA being introduced? (2)
- personnel ready with charged hoselie
2. flow path determined, perferably upwind
What mode of attack is perferred tactical consideration?
Transitional attack
How long to allow for ventilation prior to entering structure?
30- 60 seconds
Where shall exhaust be located?
fire area
What is size of exhaust opening?
ratio of 2:1 to entry size, minimum 1:1
Why should exhaust outlet be protected?
potential exposures
What are indicators of effectiveness of PPA? (2)
- not enough flow (smoke/ flames/ heat) at EXHAUST
- too much flow (smoke/ flames/ heat) at BACKFLOW
- PPA discontinued/ re-evaluated
What can be done to make PPA ineffective?
making additional openings adjacent to fire area
What does making additional openings adjacent to fire area may accomplish?
creates additional flow paths with potential to draw fire into all flow paths
What can be used for exposure control (where seperating walls have been breached)?
PPV
** strip malls/ appartments (due to plumbing, cracks)
What may occur at exhaust during PPA?
“blow torch” effect
What are precautions to be considered for PPA? (4)
- do not direct stream into PPA exhaust
- check all concealed spaces
- ensure environment does not contain CLass B chemicals or dust explosion potential
- not recommended for larger, open spaced, high ceilinged structures
What structure is PPA NOT recommended for?
large, open, high ceilings
