Utility Emergencies 2014 Flashcards
What is it called when there is a flow of an electric current across a gap between two conductors?
Arc
What is the name for a device which provides transition between underground cable to overhead electrical lines or conductors?
Pothead
What is the path through which electric current is intended to flow called?
Circuit
What is the voltage range for primary electric service lines?
2000 to 50,000
What is the voltage range for secondary electric service lines?
Less than 2,000 volts
How long does electricity need to be out for it to be considered a “sustained outage”?
More than 2 minutes
What is the voltage range generally for transmission lines?
60,000 to 500,000 volts
What is the unit of measure of electric potential called?
Volt
What is the APWA color code for underground electrical lines?
Red
What is the APWA color code for underground gas lines?
Yellow
What is the APWA color code for underground communications lines?
Orange
What is the APWA color code for underground potable water lines?
Blue
What is the APWA color code for underground reclaimed water lines?
Purple
What is the APWA color code for underground sewer lines?
Green
What is the APWA color code for temporary survey markings?
Pink
What is the APWA color code for proposed excavation?
White
What is the vapor density of methane gas?
.55
What is the pungent odorant that is added to the natural gas as a safety precaution?
Mercaptan
When is mercaptan added to natural gas?
At the distribution site
What is the flammable range of natural gas?
between 5% and 15%
What is the ignition temperature of natural gas?
1200 F
What is the primary objective regarding mitigating the hazard of an inside gas leak?
Turn off the gas to the specific appliance, if possible, or shutting off the gas to the entire structure
What is the expansion ratio of natural gas?
600:1
What, typically, is the operating pressure range of gas lines?
.25 to 55 psi
What is the range in size of natural gas transmission lines and what is their upper pressure limit?
6” to 30” and 450psi
What are indicators of a possible pipeline leak?
Hissing or roaring sound
Unusual odor
Dead/discolored vegetation
Fire coming from the ground
Dirt being blown in the air
Water bubbling
A dry spot in a moist field
What are installed at all major vehicular road and railroad crossings to prevent pipeline damage?
Road casings
What are the trade names for flexible natural gas lines which is sometimes used as an alternative to black iron pipe?
Corrugated stainless steel tubing (CSST), Trac Pipe, Ward Flex
What is the proper sequence for shutting off the utility in either a leak or fire situation?
- At the appliance if it can be done safely
- At the meter
- At the curb box
When performing a gas shut off at a curb valve, if the nut for the cover cannot be manipulated, how should the cover be removed?
Use a striking tool to break the cast iron cover
What should be done if the curb box valve cannot be accessed due to debris or dirt?
The curb box should be removed by digging around the box with a shovel
What is the general rule for positioning at a gas leak for the first arriving unit and all other incoming fire apparatus?
No closer than 100’ for the first arriving unit, minimum of 300’ for all others
What shall happen if arriving on scene of a gas leak and there is an odor present?
The apparatus shall be moved immediately
What should crews avoid parking over when responding to a gas leak?
Sewers, valve covers, and manhole covers
When should an outside gas leak be upgraded to a hazardous materials response?
When the break in the line is reported to be over 2” in diameter
What is the initial alarm response for an outside gas leak?
1 Engine, 1 Truck or Rescue
What is a serious hazard, aside from the gas itself, during an outside gas leak?
The build of static electricity ( up to 24,000 volts)
Personnel should not attempt to handle any pipe at the site of an outside gas leak. If it becomes necessary, what should be done prior to coming in contact with it?
An approved grounding device shall be attached
At an outside gas leak, fire department personnel shall ensure no persons enter an un-shored trench that is deeper than what?
5’