Chapter 6: Calculating Required Fire Flows Flashcards
What is the definition of Required Fire Flow (RFF)?
The amount of water that must be applied to the fire in order to control and/or extinguish it in a reasonable amount of time.
What are the 3 methods of determining required fire flow for manual fire fighting operations?
- The Iowa State Formula;
- The National Fire Academy Formula;
- The Insurance Services Office Formula
Who correctly theorized that if water could be broken up into little drops and discharged across the fire, it would absorb the heat and dilute the burning gases?
Glenn Griswold
Griswold settled on an impinging-stream designed nozzle that created optimally small droplets of water at pressures between _____ and _______ psi?
50 and 275 psi
Griswold founded the:
Fog Nozzle Company
Griswold’s company produced nozzles called the:
Griswold Fognozl (Also called the California Fognozl)
His Coast Guard research involved inserting fog streams via applicator pipes into completely closed rooms (except a small exhaust opening) containing oil fires:
Lloyd Layman
Lloyd Layman’s fire attack method was the:
Indirect attack
Lloyd Layman’s fire attack method does not work well on:
Incipient fires
Floyd Nelson and Keith Royer founded the:
International Society of Fire Service Instructors
What are the 2 fundamental principles was the Iowa State Formula based on?
1) 1 gallon of water will produce, with a margin of safety, 200 cubic feet of steam
2) 1 gallon of water will absorb, with a margin of safety, all of the heat that can be produced with the O2 available in 200 cubic feet of normal air
1 cubic foot of pure O2 combined with ordinary fuels produces ____ BTUs?
535 BTUs
Air contains __% of oxygen?
21%
Flame production stops when O2 levels drop below __%
15%
Only __% of air is available for heat production
7%
The number of BTUs produced by 1 cubic foot of air is:
37 BTUs
1 gallon of water converted to 200 cubic feet of steam absorbs _____ BTUs?
9,330 BTUs
Royer and Nelson concluded that 1 gallon of water can absorb all of the heat produced by _____ cubic feet of air?
200 cu. ft
Nelson and Royer determined that the maximum time required for effective use of the adjustable fog nozzle is:
30 seconds
The National Fire Academy is a:
Federal government agency (Department of Homeland Security)
This “quick calculation” formula can be used as a tactical tool to determine fire flow requirements on scene:
National Fire Academy Formula
The NFA advises that the NFA formula is considered reliable only if __ floors or fewer are on fire:
4 floors
Before exposures or other additions, the NFA formula is:
Square footage of one floor of the structure divided by 3
If more than one floor is involved and before exposures and other additions, the NFA formula is:
Square footage of one floor of the structure divided by 3, multiplied by the number of floors
When using the NFA formula, you should add __% of fire flow for each side of the building with exposures?
25%
In buildings of fire-resistive construction, if other floors are not yet involved but are threatened by possible extension of fire, those floors should be considered an:
Exposure;
Add 25% of fire flow for each exposure
This formula has never been validated by definitive scientific or practical testing:
The NFA Formula
Their mission is to provide useful and reliable risk evaluation info to property insurance companies:
The Insurance Services Office
Fire fighters use this formula to calculate fire flow in manual fire fighting the least?
The Insurance Services Office Formula
This formula was not designed to be used on the fire ground:
The Insurance Services Office Formula
When using this formula to determine fire flow in manual fire fighting, the user has to determine the construction type of the involved structure:
The Insurance Services Office Formula
The Insurance Services Office Formula is not applicable to these structures:
1 and 2 family dwellings not exceeding 2 stories
When calculated and applied properly, in manual fire fighting, this fire flow formula is generally considered the most reliable:
The Insurance Services Office Formula
The constant number extrapolated during the research to develop the Insurance Services Office Formula is:
18
When using the Insurance Services Office Formula, what is the coefficient used for wood frame construction?
1.5
When using the Insurance Services Office Formula, what is the coefficient used for ordinary construction?
1.0
When using the Insurance Services Office Formula, what is the coefficient used for heavy timber construction?
0.9
When using the Insurance Services Office Formula, what is the coefficient used for noncombustible construction?
0.8
When using the Insurance Services Office Formula, what is the coefficient used for fire resistive construction?
0.6
In the Insurance Services Office Formula, A is the:
Area of the floor
In the Insurance Services Office Formula, C is a:
Coefficient related to the type of construction for the occupancy in question
List the coefficients related to construction type for use in the Insurance Services Office Formula in consecutive order:
- Wood frame construction: C = 1.5
- Ordinary Construction: C = 1.0
- Heavy Timber Construction: C = 0.9
- Noncombustible construction: C = 0.8
- Fire-resistive construction: C = 0.6
In the Insurance Services Office Formula, all floors are included in the area except:
Basements
In the Insurance Services Office Formula, if the building is constructed of fire-resistive materials and its vertical openings are unprotected, consider the ____ largest successive floor areas as its area:
6
In the Insurance Services Office Formula, if the building is constructed of fire-resistive materials and its vertical openings are properly protected, consider the ____ largest successive floor areas as its area:
3
The Insurance Services Office recommends that the calculated fire flow be rounded to the nearest ___ gpm if the flow is less than ____ gpm, and to the nearest ___ gpm if the flow is greater than ___ gpm?
- 250 gpm
- 2,500 gpm
- 500 gpm
- 2,500 gpm
In the Insurance Services Office Formula, the minimum fire flow planned for any structure should be:
500 gpm
In the Insurance Services Office Formula, the maximum fire flow, depending on the type of structure, should be:
______ gpm for wood frame construction;
______ gpm for ordinary and heavy timber construction;
______ gpm for non-combustible construction;
______ gpm for fire-resistive construction;
______ gpm for a normal one-story building of any type of construction
8,000 gpm; 8,000 gpm; 6,000 gpm; 6,000 gpm; 6,000 gpm
In the Insurance Services Office Formula, the factors that require adjusting the fire flow include:
- The level of fire hazard
- The presence of sprinkler protection
- Exposures
In the Insurance Services Office Formula, when adjusting fire flow for additional factors, the maximum fire flow may be increased to ______ gpm:
12,000 gpm
In the Insurance Services Office Formula, when adding to the flow for fire hazard level, the basic fire flow may be reduced up to ___ percent for low-fire-hazard occupancies or increased up to ___ percent for high-fire-hazard occupancies?
25%;
25%
In the Insurance Services Office Formula, when adding to the fire flow for automatic sprinkler systems, the basic fire flow may be reduced by ____ percent for complete auto-sprinkler protection, and up to ___ percent for buildings made of fire-resistive or non-combustible materials and have a low fire hazard:
50%;
75%
In the Insurance Services Office Formula, a percentage should be added to the adjusted fire flow for structures exposed within _____ feet of the fire area under consideration?
150 feet
In the Insurance Services Office Formula, when adjusting the fire flow to incorporate exposures, the total percentage shall be the sum of the percentages for each side, bu shall not exceed ___ percent of the fire flow?
75%
In the Insurance Services Office Formula, an exposure 50 feet from the fire building requires an additional __ percent per side?
15%
In the Insurance Services Office Formula, wood frame structures separated by less than ___ feet shall be considered one fire area:
10 feet
In the Insurance Services Office Formula, normally an unpierced party (common) wall may warrant up to a ___ percent exposure charge?
10 percent
In the Insurance Services Office Formula, where wood shingle roofs could contribute to spreading fires, add ___ gpm:
500 gpm
In the Insurance Services Office Formula, any noncombustible building is warranted a ___ coefficient?
0.8 coefficient
In the Insurance Services Office Formula, if residences are continuous as with row houses and town homes, a minimum fire flow of ____ gpm is recommended:
2,500 gpm
Comparatively, manual firefighting is much less efficient than:
Automatic Sprinkler Systems
Each sprinkler will flow about __ to __ gpms?
8 to 15 gpms
In general, the NFPA indicates that 5 or fewer activated sprinklers extinguish more than __ percent of all fires in sprinklered buildings:
90 percent
Required flow rates for automatic sprinkler systems include only the amount of water the system is designed to flow:
On its own. Not to include the supplemented amount at the fdc
What are the 2 methods of designing sprinkler systems recognized by NFPA 13?
- Pipe schedule method
2. Hydraulic calculation method
NFPA 13 limits new sprinkler systems being designed by the pipe schedule method to occupancies of less than _____ square feet?
5,000 square feet
The primary advantage for using the pipe schedule method for designing sprinkler systems is:
The ease of calculation, particularly with smaller systems
This method of designing fire sprinkler systems tend to use larger pipe and therefore is the less economical method:
Pipe schedule method
The pipe schedule method does not take this into consideration:
Friction loss
NFPA 13 requires extra hazard occupancies to use this method for designing sprinkler systems?
Hydraulically calculated method
Buildings over 5,000 square feet in size may have a pipe schedule sprinkler system if they have a residual pressure of ___ psi available at the top line of sprinklers for both occupancy classes:
50 psi
This method of designing fire sprinkler systems involves using mathematical calculations to determine the required piping and other design factors:
Hydraulic Calculation Method
Which class of standpipes are equipped with 2 1/2” discharges?
Class 1
If a high rise structure is equipped with a single Class 1 standpipe, that system is required to have a minimum available flow rate of ___ gpm without being boosted by the fire department?
500 gpm
If a high rise structure is equipped with more than one Class 1 standpipe, the first system must have an available flow of ___ gpm, and each additional standpipe must have available ___ gpm, up to a maximum of ____ gpm?
500 gpm;
250 gpm;
1.250 gpm
A high rise structure with a Class 1 standpipe requires a pressure of at least ___ psi at its most hydraulically demanding discharge?
100 psi
A structure that is not considered a high rise that is equipped with a class 1 standpipe is allowed to achieve its flow requirements by being supplied by:
The fire department
This class of standpipe is designed to be used by building occupants and usually have ___ feet to ___ feet of unlined ____ inch cotton fire hose?
Class 2;
75-100 feet;
1 1/2 inch
Class 2 standpipes require a flow of ___ gpm at a minimum of ___ psi, with no increased requirements for having multiple standpipes?
100 gpm;
65psi
Class 3 standpipe water supply requirements are:
Identical to those for Class 1 standpipes
Class 3 standpipe systems are a:
Combination of class 1 and class 2 systems