Ch4 Hoseline Selection, Stretching, and Placement Flashcards
(21 cards)
Heat produced by 1lb of wrapping paper
7,100 Btu
Heat produced by 1lb of styrene foam
18,000 Btu
Practical max flow rates for 1 1/2”, 1 3/4”, 2”, and 2 1/2” hose
1 1/2” = 125gpm
1 3/4” = 180gpm
2” = 225gpm
2 1/2” = 325gpm
Rule of thumb for estimating amount of hose needed inside large building
Length+Width (of building), plus one length of hose for each floor above or below level of fire…available AT THE DOOR
Max number of hoselines per stairwell
2
Stretch hose on outside of the building if the fire is on the ___ floor or higher
Fourth
Three priorities for hoseline positioning
- Protect human life
- Confine the fire
- Extinguish the fire
The greatest protection from radiant heat
Distance
Functions of the nozzle (3)
- Regulate the amount of water
- Increase the velocity of the water
- Give the stream shape
Two main types of fog nozzles
- Constant pressure
- Constant gallonage
Hole size needed for cellar nozzle or distributor
10” x 10”
Gate valve placement for cellar nozzle or distributor
One hose length back from device
Reach of cellar nozzle
50’ or more
Reach of distributor
Only 15-20’
Expansion ratio of high-ex foam
400:1 - 1000:1
What circumstances must be in place to enter high-ex foam blanket (5)
- Entry is for life saving purposes or fire containment
- All members are properly equipped
- Electricity is shut off
- RIT on standby at point of entry
- Charged hoseline
Basic components of CAFS system (3)
- Foam concentrate supply
- Injection device to deliver concentrate to water stream
- Source of compressed air to be injected into foam/water solution
Foam expansion ratio created by fog nozzles
2:1 or 3:1
Foam expansion ratio created by air-aspirating nozzles
7:1 or 10:1
Proportion used for Class A foam
0.3 - 0.6%
Proportion used for Class B foam
3-6%
