Chap 8 Extinguishing Agents Flashcards
Document created by fire service personnel to detail the various aspects of a building before a fire or incident at the building.
Pre incident plan
Systematic approach to learning the major components of a building in order to obtain information that can be used at a future fire or other incident at that building.
Preincident planning
Materials used to extinguish the fire.
Extinguishing Agent
Pressure on a water distribution system during normal demand
Normal Operating Pressure
When water is heated to the boiling point, it converts to steam and expands how much?
at 212f water expands 1700 times its original volume.
Three basic methods water extinguishes fire:
Cools the burning material
Smothers the fire
Separates the fuel from heat
The amount of water needed to smother a fire.
Flow requirement
How many nationally accepted formulas for figuring flow requirement? What are they?
3
- National Fire Academy Formula
- Iowa State University Formula
- Insurance Services Office Formula
National Fire Academy Formula
NFF=(LxW/3)x Percentage involved
Iowa Formula?
NFF= V/100
V=Volume (LxWXH)
This type of nozzle has a tremendous amount of cooling capability because of its great surface area due to more droplets.
Fog nozzle.
Potential Problems With fog nozzles.
Higher operating pressures.
Can disrupt natural thermal layer if applied incorrectly
Can create steam
This nozzle has greater reach and penetration. Wind does not affect the stream as much as others.
Smooth bore nozzles.
The pressure that is lost during while trying to create an effective fire stream.
Friction Loss
Steps to reduce friction loss
- Reduce Hose Length
- Larger Hose
- Reduce number of couplings and appliances
- Reduce number of bends and kinks
- Nozzle Types
Three steps that can be used to figure the pump discharge pressure?
- Calculate the constant.
- Nozzles (100 or 75 psi , 80 for master, 50 for smooth bore)
- Calculate additional pressure needed due to elevation
- Calculate FL in the hose
Simpler term formula determining GPM
29.7 X tip diameter squared X Square Root of the pressure
Whats the subsurface injection technique with foam?
Tactic of introducing foam at the bottom of a bulk storage tank, allowing the foam to float to the top and blanket the product.
Two basic types of hazardous materials foam is typically used on.
Hydrocarbons and polar solvents
Petroleum based products such as gasoline, benzene, and toluene.
Hydrocarbons
Water soluble compounds. Alcohol based products such as ethanols, ketones, lacquer thinners and even some acids
Polar Solvents
What percent to manufacturers of foam require for Polar Solvents?
Hydrocarbons?
6% for Polar Solvents
3 % hydrocarbons
Ingredients to create a foam blanket?
Air
Water
Foam
Created by mechanical agitation
When using an inline eductor a vacuum is created through what?
Venturi
