TB 011 - Pressurized Dry Chemical Fire Extinguishers Flashcards
In Dry chemical extinguishers the chemical itself is?
Baking soda
Dry Chemical, in the presence of heat, releases _____ ____ and water vapor which provides a smothering action.
Carbon dioxide
Generally dry chemical is most effective on fires involving ______ _____, ______, and _____ _____.
Flammable liquids, gases , and liquefied gases
Dry chemical is approximately _____ as effective as ____ on hydrocarbon fires, including methane, for a given size extinguisher.
Twice
C02
There has been an increasing use of dry chemical on Class __ fires, especially in textile fibers such as cotton.
Class A
A cloud of dry chemical is similar to a
Flame arrestor
When a car fire involving occupants is encountered, there are certain advantages to using dry chemical; the powder can be used as a
Heat screen
The dry chemical in these extinguishers can also be used to
Neutralize acid spills
When an acid spill is encountered, pull the locking pin, hold the nozzle _ or __ feet above the acid, squeeze the valve just enough to allow the powder to flow gently from the nozzle and spread the powder over the surface of the acid.
2-3 feet
A disadvantage of using dry chemical is its ____ ____ ____ after extinguishment.
Lack of control
It is ineffective on metal fires such as
Magnesium and sodium
Dry chemical is
Non toxic
Although some irritation of the ____ and _____ passages may be experienced, there should be no residual effect under normal conditions.
Throat and nasal passages
Because of its _______ characteristics, dry powder can be used safely’ on electric fires, such as fires involving oil cooled electric switches and transformers.
Dielectric
Dry chemical extinguishers have slight ____ and ______ properties
Corrosive and abrasive
The extinguisher consists of a heavy gauge steel tested to ____psi
600 psi
The extinguisher consists of a ______ reinforced hose
Nylon
The extinguisher consists of a positive control _____ _____ _____
Squeeze grip valve
The extinguisher consists of a nozzle which shapes the dry chemical into a ___degree fan stream
60 degree
The extinguisher consists of an air pressure gauge protected by a
Gauge guard
The shell is filled with ____pounds of dry chemical and then pressurized to approximately _____ psi with compressed air.
20 pounds
165 psi
This extinguisher has a rating of
20-B,C (20 sqft)
The discharge time of a 20- pound dry chemical extinguisher with the valve fully open is
10seconds
The 20 pound CO 2 extinguisher in use on the Department will last
60 seconds
