TB 95 Flow Mix Model 500-Class A foam Flashcards
The easiest way to make Class “A” Foam is through the addition of ____ to a 500 gallon apparatus water tank. This yields a ___ foam/water ratio.
2-1/2 gallons of concentrate / 0.5 %
The tank mixing method has been a source of some controversy due to the cleansing action of the detergent within the tank and fire pump. Additionally, the tank must be____ after the use of the foam to preclude contaminating subsequent water.
purged
At this time tank mixing is ___ an approved method and shall ___ be used.
not
Aspirating nozzles
A disadvantage with this nozzle is that more of the energy from the water is used to ___ to create foam and less energy is available to project the foam resulting in reduced discharge distances.
educt air
Aspirating nozzles
Foam concentrate is usually mixed at ___ by volume and is expanded at a ratio of up to 20:1.
0.3 to 1.0%
The Model 500 design incorporates the use of a ___ that supplies water pressure around a bladder-type tank containing the foam concentrate
Differential Pressure Valve
Refilling requires approximately ___ and primary water flow is unaffected during the procedure.
two minutes
The Flow Mix Model 500, ___ proportioner works on the principle of line pressure being exerted on a bladder filled with Class “A” Foam.
five gallon
DO NOT EXCEED maximum operating pressure of ___.
450 psi.
The Flow Mix Model 500 will accurately proportion up to ___ concentrate into the line at flow rates up to 300 gpm.
1 %
Flow rates between ___ gpm will cause proportioning accuracy to drop off slightly.
300 and 400
A significant decrease in proportioning accuracy will result when flow rates above ____ are utilized.
400 gpm
The Flow Mix Model 500 can be used with any handline or combination of lines up to ___.
400 gpm
At flow rates above ___ the Metering Valve must be set to a higher percent setting than is actually desired to attain adequate proportioning.
400 gpm
Refill Position
When approximately ___ have been pumped, the water from the discharge tube will stop flowing and there will be increased resistance in the hand pump.
five gallons
An initial setting of ___ foam is recommended. This setting will help reduce water damage and increase the length of time before a refill of the unit becomes necessary.
.2 %
Class “A” Foam may be used as an effective overhaul tool, if applied in a judicious manner. The recommended initial setting is ___.
0.3 to 0.5 %.
The 95 gpm air aspirating nozzle will produce a good quality finished foam that will adhere well to ____.
vertical surfaces.
Exposure Protection:
The recommended beginning mixture is ___ on the Metering valve.
0.3
In general, foam will be visible for approximately ___ in hot weather, up to___ in cool weather. As long as foam is visible, the treated fuel will remain wet.
one-hour / four-hours
Brush
When foam is applied in this manner it will provide a layer of insulation from heat. The recommended initial setting is ___.
0.5 to 0.6 %.
When treating Duff, the goal is to penetrate the fuel layer so fire is not carried by untreated fuels below the foam cover or wet top layer. A straight stream nozzle setting with a mixing action achieves the best results. The recommended initial setting is ___.
0.1 to 0.2 %.
Dumpsters and Rubbish
Finished foam applied with the 95 gpm air aspirating nozzle will provide a foam with body but still wet enough to penetrate. The recommended setting is ___.
0.3 to 0.4%.
Finished foam will cool, wet and seal piles of tires. It will provide a quick knockdown with reduced tendency to reflash. The recommended initial setting is ___.
0.3%.
Class “A” Foam can be effective on auto fires using standard spray nozzles. It will greatly reduce overhaul; however, it can create a slippery road surface. The recommended initial setting is___.
0.3 %.
