10892- NS.M07.5741 WE - PREVENT ACCIDENTAL IGNITION AND RECOGNIZE AND REACT TO
GENERIC ABNORMAL OPERATING CONDITIONS QUESTIONS ANSWERED CORRECTLY
Types of AOCs - Answers Any unplanned or uncontrolled escape of gas, fire, or explosion (above or
underground)
any pressure of a gas system that exceeds the operating limits - Answers a relief valve expelling gas or
telemetry pressure readings, etc.
any pressure that falls below normal operating requirements - Answers a pilot out at a customer
appliance, or telemetry reads are significantly lower than normal, etc.
Pipeline that has NO pressure that was last known to be in service, as indicated by the following: -
Answers Inadvertent shutdown. valve closed (when it should be open). Broken line. Excess flow valve
(EFV) activated. Pressure limiting device activated, etc.
pipeline facility installation that no longer meets code requirements or company policy - Answers
bent riser/other aboveground piping, pipe/coating nicked or gouged during excavation, grease stem
on valve broken or damaged, inadequate support or excessive bending or loading on facilities, valve
stuck and unable to turn, regulator or meter failure, regulator vent too close to a source of ignition,
air intake, opening to a building, or unsafe electrical source, underground pipeline exposed (when
should be buried), meter/riser enclosed or in an unventilated space.
natural gas is a naturally occurring hydrocarbon gas mixture that consists of - Answers methane but
includes varying amounts of other higher alkanes, and sometimes a small percentage of carbon
dioxide, nitrogen, hydrogen sulfide, or helium.
characteristics - Answers natural gas is non-toxic, colorless, odorless, and tasteless, small amounts can
be breathed without ill effects, hazardous because it displaces oxygen, one spark can ignite natural
gas
ignition temperature of natural gas, assuming perfect combustion conditions is - Answers about
1,100-1,200 degrees Fahrenheit
"lean" gas to air mixture - Answers below the lower explosive limit (LEL) there is not enough gas to
ignite, even if an ignition source is present.
"rich" gas to air mixture - Answers above the upper explosive limit (UEL) there is too much gas to
ignite, even if ignition source is present.
source of ignition can be - Answers cell phone, doorbell, even static electricity.
LEL - Answers 5% natural gas(4% indiana)
UEL - Answers 15% natural gas (14% indiana)
most ideal gas-to-air combustion mixture ratio - Answers 10%
gas concentration of 1/5 (20%) of the LEL can be detected/smelt by - Answers an odorant
mercaptan is - Answers a chemical containing sulfur that produces a rotten egg or garlicky odor.
all leaks are classified as grade - Answers 1, 2, 2+, 3
all leaks means leaks found on... - Answers jurisdictional facilities, including mains, company service
lines, customer service lines, and customer meter settings.
factors that affect the classification of leaks: - Answers location, ignition sources, surface conditions,
volume or how much gas
location - Answers the location of the leak with respect to surrounding structures and enclosures such
as basements, electrical and telephone conduits, manholes, and sewer pipes.
ignition sources - Answers the number of possible sources of ignition such as open flames, gasoline
engines, electric engines, and static electricity.
surface contitions - Answers surface and frost conditions that could create the possibility of gas
migrating to other areas.
volume or how much gas - Answers the relative magnitude or extent of the leakage area and volume
of gas escaping
factors that influence the patterns of leaks - Answers soil, line pressure, leak size, depth of cover,
water content in soil, variation in soil compaction, voids, frost and pavement
leaks can be caused by - Answers corrosion, damage by outside forces, faulty material, earth
movement, poor workmanship, and other AOCs
conditions indicating gas leaks - Answers odor, vegetation, insects, fungus, sound, water bubbling
odor - Answers odorant added to live gas if the concentration is 1/5th (20%) of the LEL so it can be
dectected
vegetation - Answers deteriorating vegetation is a potential sign of a gas leak in the area.
GENERIC ABNORMAL OPERATING CONDITIONS QUESTIONS ANSWERED CORRECTLY
Types of AOCs - Answers Any unplanned or uncontrolled escape of gas, fire, or explosion (above or
underground)
any pressure of a gas system that exceeds the operating limits - Answers a relief valve expelling gas or
telemetry pressure readings, etc.
any pressure that falls below normal operating requirements - Answers a pilot out at a customer
appliance, or telemetry reads are significantly lower than normal, etc.
Pipeline that has NO pressure that was last known to be in service, as indicated by the following: -
Answers Inadvertent shutdown. valve closed (when it should be open). Broken line. Excess flow valve
(EFV) activated. Pressure limiting device activated, etc.
pipeline facility installation that no longer meets code requirements or company policy - Answers
bent riser/other aboveground piping, pipe/coating nicked or gouged during excavation, grease stem
on valve broken or damaged, inadequate support or excessive bending or loading on facilities, valve
stuck and unable to turn, regulator or meter failure, regulator vent too close to a source of ignition,
air intake, opening to a building, or unsafe electrical source, underground pipeline exposed (when
should be buried), meter/riser enclosed or in an unventilated space.
natural gas is a naturally occurring hydrocarbon gas mixture that consists of - Answers methane but
includes varying amounts of other higher alkanes, and sometimes a small percentage of carbon
dioxide, nitrogen, hydrogen sulfide, or helium.
characteristics - Answers natural gas is non-toxic, colorless, odorless, and tasteless, small amounts can
be breathed without ill effects, hazardous because it displaces oxygen, one spark can ignite natural
gas
ignition temperature of natural gas, assuming perfect combustion conditions is - Answers about
1,100-1,200 degrees Fahrenheit
"lean" gas to air mixture - Answers below the lower explosive limit (LEL) there is not enough gas to
ignite, even if an ignition source is present.
"rich" gas to air mixture - Answers above the upper explosive limit (UEL) there is too much gas to
ignite, even if ignition source is present.
source of ignition can be - Answers cell phone, doorbell, even static electricity.
LEL - Answers 5% natural gas(4% indiana)
UEL - Answers 15% natural gas (14% indiana)
most ideal gas-to-air combustion mixture ratio - Answers 10%
gas concentration of 1/5 (20%) of the LEL can be detected/smelt by - Answers an odorant
mercaptan is - Answers a chemical containing sulfur that produces a rotten egg or garlicky odor.
all leaks are classified as grade - Answers 1, 2, 2+, 3
all leaks means leaks found on... - Answers jurisdictional facilities, including mains, company service
lines, customer service lines, and customer meter settings.
factors that affect the classification of leaks: - Answers location, ignition sources, surface conditions,
volume or how much gas
location - Answers the location of the leak with respect to surrounding structures and enclosures such
as basements, electrical and telephone conduits, manholes, and sewer pipes.
ignition sources - Answers the number of possible sources of ignition such as open flames, gasoline
engines, electric engines, and static electricity.
surface contitions - Answers surface and frost conditions that could create the possibility of gas
migrating to other areas.
volume or how much gas - Answers the relative magnitude or extent of the leakage area and volume
of gas escaping
factors that influence the patterns of leaks - Answers soil, line pressure, leak size, depth of cover,
water content in soil, variation in soil compaction, voids, frost and pavement
leaks can be caused by - Answers corrosion, damage by outside forces, faulty material, earth
movement, poor workmanship, and other AOCs
conditions indicating gas leaks - Answers odor, vegetation, insects, fungus, sound, water bubbling
odor - Answers odorant added to live gas if the concentration is 1/5th (20%) of the LEL so it can be
dectected
vegetation - Answers deteriorating vegetation is a potential sign of a gas leak in the area.
