A702 Natural Gas Emergencies Flashcards
When is natural gas not odorized?
- when transported via interstate pipeline
- when in a liquified state
- when stored as a cryogenic fluid
Which type of vehicle is required to have an onboard gas detection system?
LNG-fueled
What are the identifiers for CNG and LNG fueled vehicles?
CNG- blue/silver diamond on right rear of vehicle
LNG- black/silver diamond on right rear of vehicle
what size hoseline should be used to protect exposures in the HZ?
“of sufficient capacity”
2 most important mitigation considerations for natural gas emergencies:
control of leak
control of ignition sources
rule of thumb for establishing HZ radius:
diameter of pipe (in inches) x 8 + 40 = HZ radius
for pipes 8” or larger evacuate a radius of ___ because ___.
150’
radiant heat
when sufficient personnel are available, establish a secondary exclusion zone at a distance where readings do not exceed ___.
1% LEL
where should the back-up/rescue be located when personnel are working in the HZ to control a leak?
“a safe distance”
Initial HZ radius for CNG leak?
50 feet, until direct reading monitoring equipment is available, then 10% LEL. secondary exclusion zone at 1% LEL.
Initial exclusion zone/HZ/evac distance for CNG fire?
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.
fusible plug for CNG container melts at __.
212 degrees F
Initial HZ radius for LNG leak?
75 feet, until direct reading monitoring equipment is available, then 10% LEL. secondary exclusion zone at 1% LEL.
Because of the high expansion ratio and cold temp of ____, the ____ may be much larger than those experienced with ___.
LNG, downwind exclusion distance, CNG
HZ radius for fires involving LNG and cryogenic containers
75 feet
static charges generated by what type of leak can cause ignition at any time?
high pressure leaks (CNG)
For a fire involving LNG or cryogenic containers, be sure that ___ and ___ are in place before any entry is made into HZ.
back-up lines and rescue standby
cryogens storage temp and expansion ratio
below 260 degrees F
in excess of 600 to 1
One cubic foot of ____ can produce ___ of 100% gas vapor and a flammable vapor cloud in excess of ____.
liquified natural gas
600 cubic feet
12,000 cubic feet
how should LNG and cryogenic container fires e extinguished?
by shutting off the fuel
T/F At an LNG leak, initial-arriving companies should attempt to approach the leak or take action to mitigate the situation.
F- only qualified facility personnel or AFD HMRT
In the event of fire inside a structure involving natural gas, notify ___ and ___.
AFD Investigator and gas company
