Water Based Specialty Systems Flashcards
What is Air-Foam (mechanical foam)
Aggregation of air filled bubbles that has a lower specific gravity then the lightest flammable liquid
Air foam is used to primarily form what on a fire
Floating blanket on flammable liquids light then water
How does air foam prevent or extinguish a fire
By excluding air and cooling the fuel
Definition of foam concentrate
Liquid foaming agent as received from the manufacturer
What is Protein Foam Concentrates
- Protein compound made from natural vegetable or animal sources (chicken beaks and feathers)
- non toxic and bio degradable
- CANNOT be used for subsurface applications
What is Fluoroprotein Foam Concentrates
Very similar to protein foam, has additives that make it excellent for subsurface applications
What does Aqueous Film Forming Foam do
-forms aqueous water based film on the surface
-moves across fuel 3-4x more quickly then conventional foam
What is Film Forming Fluoroprotein Concentrates
Uses fluorinated surfactants to make a fluid film for suppressing hydrocarbon vapours
Protein foam, Fluoroprotein foam, AFFF, FFFP are used at nominal concentration levels of
3-6% by volume of the solution discharge of the system
6% solution is primarily used in
Existing Military Facilities (being phased out)
Protein foam, Fluoroprotein foam, AFFF, FFFP are considered to be _____ expansion foams
Low
Low expansion foam has an expansion rate up to
20:1
How would you figure out the amount of gallons of foam a system could produce
3% foam concentrate with a 20:1 expansion ratio -
3 gallons of foam combines with 97 gallons of water to make 100 gallons of solution.
With a 20:1 expansion ratio, you would do 100gal x 20 = 2000gal of foam
Medium or high expansion foam concentrates are designed to produce expansion ratios of
20:1 to 1000:1
Different types and brands of concentrates shall not be ______
Mixed
What pipe should is not compatible with most foam liquids
Galvanized piping
A foam water sprinkler system is tested in the same manner as a
Deluge system
Air foam for a definite period of time at a given density can be expressed as
Gallons per minute of air foam solution per square foot (gpm/sq.ft)
After the system has completion of air foam discharge what will it do
Continue to discharge water
Foam water sprinklers are open type sprinklers that are designed to
- receive air-foam solution
- direct the solution through integral foam maker
-provide mixing chamber capacity
Foam spray nozzles combine what
Foam maker with a body and distributing deflector
When filling a container with foam how is it done
-Pumped in from bottom
-long funnel to introduce it below liquid level
How is medium or high expansion foam formed
Passage of air through a net, screen, that is wetted by an aqueous solution
How do medium and high expansion foams differ
Medium expansion foam was developed to be more wind resistant then high expansion foam in outdoors
2 types of foam generators are
-aspirators
-blowers
The capacity of foam generators is generally determined by
The time required to fill an enclosure by top application within 1-5 minutes
How does a foam aspirator work
Jet streams of foam solution aspirate air, which is then put through screens to produce foam
Aspirators generally produce foam with expansion rates of
250:1
Foam Blower generators operate how
Discharged as a spray onto screens where air is passing through from a fan or blower
The Blower to generate foam may be powered by
-electric motors
-internal combustion engines
-air
-gas
-hydraulic
-water motors
AFFF and FFFP will produce foam from a ______ sprinkler
Standard
If a standard sprinkler is going to be used for foam, what must it have
A specific listing to be used with foam
With water foam systems, the temp rating of sprinklers at the roof of ceiling should be within what range
250-300F
With water foam systems, the temp rating of sprinklers at an intermediate level should be within what range
135-170F
(Unless ambient conditions require more)
What systems can aqueous film forming foam be used in
-wet
-dry
-pre action
Overtime, the foam solutions react with steel pipe in what way
The solutions lose their capacity to produce foam
Pre-primed foam systems should be flushed when and through what
Annually, through a minimum 2” connection
What is the exception to not having to flush annually
Using special “alcohol type” AFFF or FFFP concentrates
What foams are susceptible to forming sediment when stored in solution
Alcohol type AFFF and FFFP
Alcohol Type AFFF and FFFP should not be
Pre primed without authorization from the manufacturer
What is the least desirable system to use with AFFF and FFFP
dry pipe systems
Why is there no need to pre prime a pre action system
Because it is proportioned into the system on operation
The design discharge rates for foam solutions should provide densities of not less then _____ for a period of ____ minutes
0.16gpm per sqft, for a period of 10 minutes
The discharge time over the demand area should never be less then
7 minutes
Water supplies should be capable of supplying the design area for
60 minutes
What is the preferred method for introducing foam concentrates
Balanced pressure injection
What information do orfice plate “tell tales” have on them
-Orifice diameter
-Direction of flow
-if flow characterics change w/ flow direction
With a foam concentrate injection system, the system should be arranged so that
Periodic tests and inspections can be made without discharging foam solution.
Two options are possible in locating the proportioning controller in the sprinkler riser which are
Before or after main sprinkler valve.
If the proportioning controller is located after the main sprinkler valve, what is needed
An additional supervised OS&Y valve
(To isolate the sprinklers during proportioning test)
Combustion is a process where fuel undergoes a rapid ______
Exothermic chemical reaction
(Release of heat) with an oxidizing agent (usually air)
Fuels can be classified as
Any material that can be oxidized
The products of combustion of an organic fuel are
Carbon dioxide and water
Two types of fuels are
Polar solvent and hydrocarbon
What is a polar solvent fuel?
High alcohol content
What type of foam for polar solvent?
Alcohol resistant type foam
examples of hydrocarbons are
Gasoline, diesel, heptane
Examples of polar solvents are
Methyl alcohol, acetone
What foam is required for hydrocarbon fuels?
Standard AFFF
Components of the fire tetrahedron
Fuel,
heat,
oxidizing agent,
chemical chain reaction
Green triangle is what type of fire
Class A - ordinary combustibles
Red square type of fire
Class B
Flammable liquids
Blue circle type of fire
Class C
energized electrical
Yellow star type of fire
Class D
Flammable metals
Black hexagon is what type of fire
Class K
Cooking oils and fats
How does a liquid fuel fire burn?
The vapours that are admitted from the service of the liquid are what is burning
What does flashpoint mean?
Minimum temperature of a liquid where a liquid will form a vapour in the air near it surface that will flash or briefly ignite
What temperature is the flashpoint for a flammable liquid?
Less than 73°F
In general flammable liquids cannot be extinguished with
Water
Examples of flammable liquids are
Diethyl ether - starting fluid
Gasoline
Solvent based cements
Method for extinguishing flammable liquids are
Foam systems.
Dry chemical
Gas systems
Combustible liquids have a higher flashpoint of what temperature
100°F or greater
Paint thinner has a flashpoint of
100°F or more but less than 140°F
Kerosine has a flashpoint of
140°F or more but below 200°F
Vegetable oil has a flashpoint of
200°F or more
Fuels are designated by their ability to mix with
Water
Fuels that mix with water are
Miscible
Fuels that do not mix with water are
Non-miscible
Non-miscible fuels are generally
Hydrocarbon fuels
Hydrocarbon fuels are derived from
Fossil fuels
Miscible fuels or chemicals are also known as
Soluble liquids, solvents, polar solvents
Expansion ratios of foam increase, depending on how much they are
Aerated or agitated
High expansion foam can only be discharged through what
Hi-Ex Generators
Low expansion foam ratio
1:1 to 20:1
Medium expansion ratio
20:1 to 200:1
High expansion foam ratio
200:1 to 1000:1
Define expansion ratio
It Is the comparison of final foam volume to the original foam solution before it’s added
Two types of foam are
Chemical and mechanical
The earliest chemical forms were based upon
A chemical reaction occurring between aluminum sulphate and sodium bicarbonate
How are mechanical foams produced?
By mixing foam, concentrate with water at appropriate concentration
6 types of foams are
-protein
-Fluoroprotein
-Film Forming Fluroprotien
-Aqueous Film Forming Foam
-Alcohol Resistant Concentrate
-Synthetic detergent
P.F.F.A.A.S
Protein foam is derived from
Naturally occurring sources of protein, such as chicken beaks and feathers
What is done to protein meal before it is put into protein foam?
It is hydrolyzed in the presence of lime converted to protein Hydroslate
What is fluoroprotein foam?
Derived from protein, with small amounts of fluorochemical suffocates are added
What is film forming fluoro protein?
Protein based foam which larger quantities of fluoro chemicals have been added
What do the fluoro chemicals do to the foam?
Increase mobility
What foam has a short shelf life
Fluoroprotein
What foam is completely synthetic
Aqueous film forming foam
What is in aqueous film forming foam
Combination of flurochemical and hydrocarbon surfactants
Alcohol resistant concentrate foam produces a foam that is effective on fuels such as
Methyl alcohol, ethyl alcohol, acetone
What happens to standard foams on alcohol fires?
Agent bubbles collapse when applied to these types of fires
Most current alcohol resistant concentrate foams are based on
AFFF concentrates that water soluble polymer has been added
When alcohol resistant concentrate foam is put on a fuel what is formed
Polymeric membrane
AR-AFFFF can be used on
Hydro carbon and polar solvent fuels
What foam is the best cross functional performance for flame, knockdown, burn back resistance, and extended vapour suppression
AR-AFFF
AR-AFFF mixture % for use with polar solvent fuels
6%
AR-AFFF mixture for use with hydrocarbon fuels
3%
Synthetic detergent has what mixture in it
Non-Flurochemical, hydrocarbon type suficant
Synthetic detergents are mixtures of
Non-Fluro chemicals and hydrocarbon type surfactants
What is a surfactant
Chemicals that have the ability to change the surface properties of water
Synthetic detergents do not form
Aqueous films or polymeric membranes
What does synthetic detergent form
An aggregate of foam bubbles in the surface of the fuel
What is most used for high expansion and total flooding foam
Synthetic detergent
Air foam definition
Foam produced by the physical agitation of a solution of water and foam concentrate
Aspirate means
Draw air into the nozzle to mix with the foam solution
Batch mix means
Manual addition of foam concentrate to a water storage container
Biodegradation means
Decomposition by microbial action as with synthetic detergent or protein based agents
Boil over means
Violent ejection of flammable liquid from its container cause by vaporization of water beneath
Bund means
Contour land or a physically barrier that retains a fuel depth greater then 1”
Carcinogenic means
Cancer causing
Cohesive quality is
The ability to bind together substances
Dike means
Physical barrier that retains a fuel depth greater then 1”
Drainage (drop out) rate means
The rates at which bubbles from foam burst and release there solutions
Flash back means
Re-ignition of a flammable liquid caused by the exposure of its Vapour to an a ignition source
Flash point means
The temp at which a flammable liquid gives off enough vapour to ignite
Fluorocarbon is
An organic compound in which fluorine replaces hydrogen
Hydrocarbon pickup means
The characteristics of a fuel that is suspended or absorbed by expanded foam
Hydrophobic vs hydrophilic
Hydrophobic means water hating
Hydrophilic means water liking
Line proportioner is a device that
Siphons foam from a container to make foam solution
Olephobic means
Oil hating
Pour point means
The lowest tempature at which foam concentrations is fluid enough to pour (generally 5F)
Pressure is determined by
Friction Loss
Head loss
Losses due to orifice plate
Quarter life (drain time) means
The time required in minutes for one fourth of the total liquid solution to drain the finished foam
Also referred to as 25% drainage time
Skin fire is a fire on a solid surface where the liquid is not present passed a depth of
1”
What is the simplest means of proportioning?
Premix/dump In method
What is the standard for low, medium and high expansion foam
NFPA 11
What is the only foam that can be used with the pre-mix/dump in method
AFFF
In the pre-mix/dumping method all the water is converted to
Foam solution
What is the most common proportioning system used for system applications?
Balanced pressure proportioning
Two basic types of balanced pressure proportioning are
Bladder and pump systems
Balance pressure proportioning systems use a modified device Venturi device
A proportioner or ratio controller
The bladder in a bladder tank is what kind
Elastomeric bladder
In a pump system, the automatic pressure balancing valve regulates what
The concentrate pressure to match water pressure
In the in-line balanced pressure proportioner the pressure control valve is located where
In the return line to storage tank.
Maintains constant pressure and supply manifold that is 15 to 20 psi higher than water pressure
Line proportioning systems use what kind of storage tanks
Atmospheric
What do line proportioning systems use to pull Foam into the system?
Eductor
Two kinds of discharge devices are
Air aspirated.
Non-air aspirated
What is required so flammable vapours do not travel down any opens of system piping
Vapour seal
Minimum density in foam systems
.16gpm/sqft
Design area in foam systems
5000sqft
Minimum discharge time in foam systems
10 minutes
Max sprinkler coverage area foam systems
12 ft
Max sprinkler spacing foam systems
12ft
Where is the fire department connection installed in a foam system?
Supply side of proportioner
Foam solution testing shall be done
Annually and only by manufacture
Foam tanks are Hydro tested how often
Every 10 years at system pressure
How full must the foam tank be at all times?
80%
(25% safety factor)
When conducting a foam solution test, you must flow the system through
The proportioner
Drainage rate is
Rate at which the foam solution will drain from the expanded foam mass
OR
25% of the solution to drain the foam (quarter life)
Modern day foam can be used with what
Seawater, freshwater, brackish water
Non-aspirating nozzles will throw the foam a greater ______
Distance
Sub surface methods can only be used with
Hydrocarbons
AFFF is suitable for use with _____
Dry chem
For an alcohol fire, what nozzle is best?
Air aspirating
Synthetic detergents generally are used with a concentrate level of
1.5% to 2.5%
What will provide a thermal insulation barriers around the liquid natural gas bill
500:1 expanded foam
What is class a foam concentrate
Biodegradable mixture of foaming and wedding agents
Adding class a foam, concentrate to water can increase the effectiveness up to how much
5x
Wedding agent is similar to class a it increases
Wetting effectiveness
What protein can be used with a high back pressure foam maker?
Fluoro protein
Fixed water spray systems typically have what kind of nozzles
Open nozzles
Guideline set out for freestanding, supports for fixed water Spray systems are found in what NFPA
NFPA 15
Ultra high speed water spray systems will deliver water within how long
100 milliseconds
In ultra high-speed fixed water spray systems the network piping is
Pre-primed
Some ultra high-speed water spray systems are capable of delivering water in is a little time as
10 milliseconds
Max distance of how far must be maintained between the nozzle and hazard for fixed water spray systems
36 inches
In fixed water spray systems any system installed with nozzles less than 3/8 must have what
A strainer
Water systems use fine water droplets under
Must be under 1000 microns
Generally 100 microns
Small water droplets in a water mist system allow the system to absorb more
Radiant heat than other systems
What is the main contributor to water droplet size?
Pressure
The lower the pressure the ____ the nozzle needs to be to the fire
Closer
What is the pressure in a low water mist system?
175 psi and under
What is the pressure in an intermediate pressure mist system?
176 - 500psi
High pressure water mist system, what is the system pressure
Over 500 psi
What does local application mean with water mist systems?
Apply water mist to a specific object
What does total flooding mean with a water mist system?
Flooding an entire compartment with water mist with all nozzles (deluge)
What does zoned application mean with water systems?
System aware of volume is protected by several distinct zone each with its own detection system
Water mist systems can be used with what kind of systems
Wet, dry, pre-action, deluge
Water miss systems use ____ water compared to normal systems
Less
What is one advantage of a water system because it uses less water?
Smaller pipe size
Water mist systems are used primarily on what class of fire
Class A
When can water mist systems be used on a class B fire
If water droplet size is under 400 microns
Without proof of compatibility water mist systems should not be used on what class of fire
Class C
What do water systems use to break the water droplets into a fine spray
Atomizing agent
Water and atomizing agent can be discharged to the nozzles in two ways in a water mist system which are
Single fluid system
Twin fluid system
What does a single fluid system do in a water mist system?
Water and atomizing agent are contained in the same pipe to discharge nozzles
What does a twin fluid system? Do in a water mist system?
Itemizing agent in water are in separate pipes
Two major factors that influence the need for water mist fire systems are
Marine use
Halon Systems
Water miss systems are good where available water supplies are
Limited or where the application of water might be restricted
Water mist system expands how much more than standard sprinklers
1700x
Water mist systems cannot be used where
-On materials that react with water.
-on liquified gases that are maintained at cold temperatures
Max size water mist fire system, light hazard
52,000sqft
Max size water mist system ordinary hazard
52,000sqft
Duration of water supply for water mist system in light hazard
30 minutes
Duration of water supply for water mist systems ordinary hazard
60-90 min
The droplet of a water mist system is = to
Dv0.99 which means 99% of the liquid volume is in drops of smaller diameter
3 influential characteristics for water mist systems
Density of spray
Spray velocity
Quality of water
What are Automatic water mist nozzles
Operate independently of other nozzles by means of activation built into nozzle
What are multifunctional water mist nozzle?
Capable of operation using both automatic and non-automatic
What are non-automatic water mist nozzles
Operate as an entire system or grouping of nozzles
Strainer shall be required where on water mist systems
-The water supply
-downstream of pipe not corrosion resistant
-downstream of any water or break tank
Pipe and fittings in water, my systems must have a minimum rated working pressure of
175 psi
The max pole force on a manual release for a water miss system weight and length
40Lbs and 14”
Where must the release device be located from a water mist system?
Not more than 4 feet above finished floor
(must be at least one)
Temperature limitations for devices in water mist systems is
40°F to 130°F
In low pressure water miss systems. What is the acceptance test?
The same as standard sprinklers
In high-pressure water mist systems what is the system acceptance test
-1.5x the working pressure for 10 minutes
-110 minutes at working pressure without loss
Air test for Low pressure water mist system consist of
The same as standard sprinklers
Nozzle shall be inspected from the floor ____
Annually
How many spare nozzles with less than 50 on site?
Three spare
How many spare nozzles with 50 to 300 nozzles on site?
6 spare
How many spare nozzles with 301 to 1000 nozzles on site?
12 spares
How many spare nozzles with more than 1000 nozzles on site
24 spare
Automatic nozzles require testing after how long
20 years
Automatic nozzles require testing after how long if in a harsh environment
5 years
Maximum response time for standard fixed water spray systems
40 seconds
Minimum discharge pressure for outdoor nozzles
20psi
Minimum discharge pressure for indoor nozzles
In accordance with their listing
Max size of ultra high speed water spray system
500 gallons
Minimum duration for ultra high speed spray systems
15 minutes
NFPA for water spray systems
NFPA 15
Water spray system components must be rated for a max working pressure of
175psi
Reconditioned devices are only permitted in fixed water spray systems when
Only in existing systems
Fixed water spray systems typically have ______ nozzles
Open
Maximum size of 500 gallons in fixed water systems can be exceed if activation time of ____ is met
100 milliseconds
What is the maximum spacing Between sprinklers on a foam water sprinkler system
12 feet
