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Flashcards in A702 Natural Gas Emergencies Deck (22)
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1
Q

When is natural gas not odorized?

A
  • when transported via interstate pipeline
  • when in a liquified state
  • when stored as a cryogenic fluid
2
Q

Which type of vehicle is required to have an onboard gas detection system?

A

LNG-fueled

3
Q

What are the identifiers for CNG and LNG fueled vehicles?

A

CNG- blue/silver diamond on right rear of vehicle

LNG- black/silver diamond on right rear of vehicle

4
Q

what size hoseline should be used to protect exposures in the HZ?

A

“of sufficient capacity”

5
Q

2 most important mitigation considerations for natural gas emergencies:

A

control of leak

control of ignition sources

6
Q

rule of thumb for establishing HZ radius:

A

diameter of pipe (in inches) x 8 + 40 = HZ radius

7
Q

for pipes 8” or larger evacuate a radius of ___ because ___.

A

150’

radiant heat

8
Q

when sufficient personnel are available, establish a secondary exclusion zone at a distance where readings do not exceed ___.

A

1% LEL

9
Q

where should the back-up/rescue be located when personnel are working in the HZ to control a leak?

A

“a safe distance”

10
Q

Initial HZ radius for CNG leak?

A

50 feet, until direct reading monitoring equipment is available, then 10% LEL. secondary exclusion zone at 1% LEL.

11
Q

Initial exclusion zone/HZ/evac distance for CNG fire?

A

of sufficient size to prevent injury to public in the unlikely event on container rupture, until direct reading monitoring equipment is available, then 10% LEL. secondary exclusion zone at 1% LEL.

12
Q

fusible plug for CNG container melts at __.

A

212 degrees F

13
Q

Initial HZ radius for LNG leak?

A

75 feet, until direct reading monitoring equipment is available, then 10% LEL. secondary exclusion zone at 1% LEL.

14
Q

Because of the high expansion ratio and cold temp of ____, the ____ may be much larger than those experienced with ___.

A

LNG, downwind exclusion distance, CNG

15
Q

HZ radius for fires involving LNG and cryogenic containers

A

75 feet

16
Q

static charges generated by what type of leak can cause ignition at any time?

A

high pressure leaks (CNG)

17
Q

For a fire involving LNG or cryogenic containers, be sure that ___ and ___ are in place before any entry is made into HZ.

A

back-up lines and rescue standby

18
Q

cryogens storage temp and expansion ratio

A

below 260 degrees F

in excess of 600 to 1

19
Q

One cubic foot of ____ can produce ___ of 100% gas vapor and a flammable vapor cloud in excess of ____.

A

liquified natural gas
600 cubic feet
12,000 cubic feet

20
Q

how should LNG and cryogenic container fires e extinguished?

A

by shutting off the fuel

21
Q

T/F At an LNG leak, initial-arriving companies should attempt to approach the leak or take action to mitigate the situation.

A

F- only qualified facility personnel or AFD HMRT

22
Q

In the event of fire inside a structure involving natural gas, notify ___ and ___.

A

AFD Investigator and gas company