TB #11 Pressurized Dry Chemical Fire Extinguishers

Question 1

Dry chemical is approximately __ as effective as CO2 on hydrocarbon fire

Answer 1

Twice

Question 2

Dry chemical is ineffective on metal fires such as __ and __

Answer 2

Magnesium, sodium

Question 3

The extinguisher consists of __

Answer 3

A shell of heavy gauge steel, tested to 600 psi, nylon reinforced hose, a positive control squeeze grip valve, a nozzle which shapes the dry chemical into a 60 degree fan stream, an air pressure gauge protected by a gauge guard

Question 4

The shell is filled with __ pounds of dry chemical and then pressurized to approximately __ with compressed air

Answer 4

Twenty (20), 165 psi

Question 5

The discharge time of a 20 pound dry chemical extinguisher with the valve fully open is __

Answer 5

10 seconds

Question 6

The 20 pound CO2 extinguisher in use on the Department will last __

Answer 6

60 seconds

Question 7

Best results are obtained with this type of extinguisher by working from the __ side of fire and __ powder in over the fire

Answer 7

Windward, floating

Question 8

The extinguisher has an effective range of approximately __ to __ feet

Answer 8

15, 20

Question 9

Direct the initial discharge from a distance not closer than __ to __ feet

Answer 9

6, 8

Question 10

The extinguisher will function effectively only so long as the air pressure is between __ to __ psi

Answer 10

125, 175