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FIRE CONTROLBY TODDIREMONGER
Developed by Todd Iremonger, 2001Adapted by CCTD, 2012
OBJECTIVES
Identify characteristics of LPG vs. Natural Gas Identify standard extinguishing methods for
them Identify hazards associated with electricity
CONTROL OF GAS UTILITIES
Natural Gas LPG - Liquefied Petroleum Gas
NATURAL GAS
Mostly methane Nontoxic Classified as asphyxiant Odor - Butyl Mercaptin is added Explosive concentrations 4-14% Pressure ranges from 1/4 to 1000 psi Pressure is usually below 50 psi
LIQUEFIED PETROLEUM GAS
Mainly propane Non-toxic Odor added 1.5 times heavier than air Explosive concentrations 1.5 to 10% Gas is shipped in cylinders and tanks
INCIDENTS INVOLVING DISTRIBUTION SYSTEM
Most often caused by excavation Approach and stage from upwind side Evacuation is first concern Eliminate ignition sources in area Do not attempt to operate main valves
If burning, do not extinguish Exposures should be protected if necessary
SERVICE METER
Flow stopped by turning the cutoff valve Use hoseline for protection
SUPPRESSING CLASS C FIRES
Primary danger of electrical fires is the failure of FF’s to recognize the hazard.
Commercial and high rise buildings, power is necessary to operate elevators and /or air handling equipment so the entire building should not be unilaterally deenergized.
Once power has been shut down, fires may self-extinguish or become class A or B fires.
BULK ELECTRICAL TRANSMISSION LINES An area equal to a span between poles
should be cleared on either side of the break. Transformers have coolant liquids that may
contain PCB’s. These liquids are flammable and may be carcinogenic.
Transformers at ground level - Dry Chem. Transformers above ground - Let burn
WARNING
Stop the flow of electricity to the object involved before initiating fire suppression activities.
Consider all wires live until confirmed to be otherwise by the power company.
UNDERGROUND LINES
Most common hazard is explosions. Accumulation of gases ignited by spark Keep public clear and don’t park apparatus
over a manhole. Do not enter except to attempt a rescue. Firefighting can be done from outside. Discharge Dry chemical or Carbon Dioxide
and replace cover.
COMMERCIAL HIGH-VOLTAGE INSTALLATIONS
Water should not be used. Toxic chemicals, coolants smoke is a real
hazard. If rescue is required, search with clenched
fist or back of hand to prevent reflex actions of grabbing live equipment which may be contacted.
ELECTRICAL POWER SHUTOFF
During structural firefighting ops., power should be turned off as soon as practical.
Firefighters do not pull electricity meter. Control power at panel box initially. Emergency Generators - pulling meter does not
shut off all power.
ELECTRICAL EMERGENCIES
Never look directly at arcing electrical lines All wires treated as energized Do not cut electrical wires Use approved insulated tools Use care in raising/lowering ladders Proceed carefully where wires are down Mark downed line with appropriate tape,
inform command and on scene crews
ELECTRICAL EMERGENCIES
Do not touch vehicles in contact with lines. Solid or straight streams must not be used. Special considerations for fences. If line is in
contact the entire fence becomes charged.
REVIEW
WHICH OF THE FOLLOWING STATEMENTS INVOLVING A PIPE BREAK IN A NATURAL GAS LINE IS NOT CORRECT?
1) First concern, evacuate around break and downwind.
2) If gas is burning, extinguish the flame.
3) FF’s should not operate main valves.
4) FF’s may stop flow of gas into a building by turning cutoff valve.
2. IF THE GAS IS BURNING, FF’S SHOULD EXTINGUISH THE FLAME.
FIREFIGHTERS SHOULDN’T EXTINGUISH THE FLAME FROM LPG OR NATURAL GAS UNTIL THE SUPPLY HAS BEEN SHUT OFF.
AT FIRES INVOLVING ELECTRICAL TRANSFORMERS AND BROKEN
TRANSMISSION LINES, FF’S SHOULD ________.
1) Allow transformers to burn themselves out.
2) Clear an area equal to the height of the pole.
3) Extinguish ground level transformers with dry chem if safe
4) Determine if the lines are energized or not
4) DETERMINE IF THE LINES ARE ENERGIZED.
FIREFIGHTERS SHOULD NOT DETERMINE IF THE LINES ARE ENERGIZED OR NOT.
LEAVE THIS TO CLARK PUBLIC UTILITIES. SOME LINES MAY BECOME ENERGIZED
UPSTREAM FROM THE BREAK IF THEY ARE LAYING ACROSS POWER LINES.
DURING STRUCTURAL FIRE FIGHTING OPS, IT IS DESIRABLE FOR ELECTRICAL POWER _______.
1) To remain on until FF’s are out of bldg.
2) Shut off as soon as fire personnel arrive.
3) Remain on until bldg. becomes damaged enough to interrupt electrical service
4) Shut off unless absolutely needed.
4) SHUT OFF UNLESS ABSOLUTELY NEEDED
ELECTROCUTION IS A LIFE THREATENING HAZARD THAT SHOULD BE MITIGATED AS SOON AS POSSIBLE.
IDENTIFY THE FOLLOWING CHARACTERISTICS AS THOSE OF LPG, NATURAL GAS, OR
BOTH.
HAS NO NATURAL ODOR.
BOTH
IS LIGHTER THAN AIR.
NATURAL GAS
IS NONTOXIC.
BOTH
HAS A DISTINCTIVE ODOR ADDED TO IT.
BOTH
IS EXPLOSIVE IN CONCENTRATIONS BETWEEN 4-14%.
NATURAL GAS
IS CLASSIFIED AS AN ASPHYXIANTE
BOTH
IS DISTRIBUTED FROM GAS WELLS TO ITS POINTS OF USAGE BY A
NATIONWIDE NETWORK OF SURFACE AND SUBSURFACE PIPES.
NATURAL GAS
IS ABOUT 1 1/2 TIMES AS HEAVY AS AIR.
LPG
IS EXPLOSIVE IN CONCENTRATIONS BETWEEN 1.5-10%.
LPG
IS STORED IN TANKS AND CYLINDERS NEAR ITS POINT OF USAGE.
LPG
IS USED PRIMARILY AS A FUEL GAS IN CAMPERS, MOBILE HOMES, AND RURAL
HOMES.
LPG