TB 103 - Foam Dispensing Equipment Flashcards
Class “A” Foam Properties:
- reduces surface tension of water
- increases effectiveness of water by 3-5x
-resists quick evaporation in hot environment
-provides short term fire barrier
Class “B” Foam Properties:
- forms blanket over flammable liquids, sealing flammable vapors under foam
When applying class “B” foam, at least _____% of the stream flow should land on the flammable liquid within a well-defined, compact, elliptical area or footprint.
80%
The Hydro-Foam Nozzle uses class B foam that expands to the optimum foam range from 3:1 to ____.
6:1
This expansion range produces a foam stream that is able to withstand winds and thermal updrafts present during large scale flammable liquid fires.
The Hydro-Foam Nozzle Flows 660 GPM at 100 PSI Nozzle pressure.
What is the straight stream range?
What is the proportioned foam concentrate mixture?
180 ft reach
3% mixture
The foam concentrate inlet on the Hydro-Foam Nozzle includes an ____ ft reinforced clear plastic “pigtail” with 1-1/2” couplings.
8ft
What are the two set-ups to get foam to flow from the Hydro-Foam Nozzle?
- Hydro-Foam Nozzle by itself
- Hydro-Foam Nozzle used with Jet Ratio Controller
If operating the Hydro-Foam Nozzle BY ITSELF:
Remove the gasket from female swivel on the clear plastic “pigtail” hose. Place the ____% disc (brass/plastic type washer) into the female coupling. Place the hose gasket back into the female swivel coupling.
3%
Operating the Hydro-Foam Nozzle with the Jet Ratio Controller:
What is the max hose distance allowed from JRC discharge to Hydro-Foam Nozzle “pigtail”?
1,000 ft
Hydro-Foam Nozzle and Jet Ratio Controller
Expect to use ____ gallons of concentrate per minute of operation while water is flowing.
20 gallons
1-1/2” In-line Foam Eductor
What type of foam can you use?
Class “A” or Class “B”
1-1/2” In-line Foam Eductor
- When using 1-1/2” hose, the hose lay FROM THE EDUCTOR to the spray nozzle MUST be _____ft.
- When using 1-3/4” hose, the hose lay FROM THE EDUCTOR to the spray nozzle MUST be _____ft.
- Always use the _____ gpm spray nozzle for both 1-1/2” and 1-3/4” hose evolutions.
- Pump _____ psi to the eductor inlet.
- 150ft
- 250ft
- 125 GPM
- 200 PSI
1-1/2” In-line Foam Eductor- Selecting the Desired Mixture
- Use ____% for Class “B” flammable liquids/polar solvents.
- Use ___% or lower for Class “A” fuels.
- 3%
- 1%
Cleaning the 1-1/2” In-line Foam Eductor (TFT Brand)
Do not back flush above ____ psi. Rapid back flush discharge from the pick-up tube could cause INJURY.
75 psi
Pumping Foam Using the 1-1/2” In-line Foam Eductor (Williams’ Brand)
Moving the Water-Foam selector ring from the FOAM position to the water position without decreasing pump pressure ______ % will result in a LARGE INCREASE in NOZZLE PRESSURE.
10%
1” Bubble Cup Spray Tip
To use the aspirating feature slide the gray sleeve portion of the spray tip FORWARD. When the sleeve is in the fully extended position, a _____ on the shaper will be visible at the base of the gray sleeve.
white line
- 1” Bubble Cup Spray Tip produces a foam expansion ratio of _____.
- What “Class” foam is used in conjunction with the Bubble Cup?
- 8:1
- Class “A”
Class “A” Foam Thru Bubble Cup
- Tests have demonstrated that air bubbles burst when exposed to temperatures in the range of _____ degrees Fahrenheit.
- Foam blankets break down _____ to _____ minutes following application.
- 170
- 15-to-30 mins
Bubble Cup Spray Tip Foam application rates for Class A foam:
Foam Performance
___________ is the elastic force of a liquid which tends to MINIMIZE the SURFACE AREA thus causing droplets to form.
-Surface Tension
(The high surface tension of water is a hindrance in firefighting.)
• Water inherently has “high surface tension” characteristics that hinder its ability to soak and penetrate into deep-seated Class “A” combustibles.
• Typical surface tension of water (measured in dynes) is about 70 dynes per centimeter. When just 0.1% of Class “A” foam (surfactant) is added, it will reduce the tension to as little as 30 dynes.
Foam Performance
________ is the ratio of the volume of finished foam to the original volume of nonaspirated solution. The Quantity of bubbles.
Expansion Ratio
Foam Performance
_________ is the rate at which the foam solution is RELEASED from the bubble structure of finished foam. The QUALITY of BUBBLES.
Drain Time
Foam Performance
__________ is the FLUIDITY of foam. An indication of foam’s ability to cling and stick to a surface.
Finished Foam VISCOSITY
(This attribute is important in pretreatment and exposure protection.)
