NGA 70: PROPERTIES OF NATURAL
GAS AND ABNORMAL OPERATING
CONDITIONS BASED ON STUDY
MANUAL NOT IN-CLASS CORRECT
100%
Range of flammability (definition) - ANSWERThe range which gas will burn. The range
of flammability for natural gas-air mixtures is approx. 5% to 15% natural gas
Regulating Station - ANSWERReduces the pressure and measures the quantity of gas
received from the distribution pipeline and prepares it by putting in odorants into the gas
stream for consumers.
Service Line - ANSWERA pipe that transports gas from a common source of supply to a
meter set assembly
Service Regulator - ANSWERA mechanical device that controls the flow of gas at a
constant pressure to meet downstream customers' demand. Standard delivery pressure
is normally 7 inches water column
Specific Gravity - ANSWERThe weight of gas compared to weight of air. The specific
gravity of natural gas is 0.6
Station By-Pass - ANSWERTakes over gas flow by maintaining it in the event of
emergency shutdown
Range of flammability (definition) - ANSWERThe range which gas will burn. The range
of flammability for natural gas-air mixtures is approx. 5% to 15% natural gas
Regulating Station - ANSWERReduces the pressure and measures the quantity of gas
received from the distribution pipeline and prepares it by putting in odorants into the gas
stream for consumers.
Service Line - ANSWERA pipe that transports gas from a common source of supply to a
meter set assembly
Service Regulator - ANSWERA mechanical device that controls the flow of gas at a
constant pressure to meet downstream customers' demand. Standard delivery pressure
is normally 7 inches water column
, Specific Gravity - ANSWERThe weight of gas compared to weight of air. The specific
gravity of natural gas is 0.6
Station By-Pass - ANSWERTakes over gas flow by maintaining it in the event of
emergency shutdown
Aldehydes - ANSWERA toxic substance formed from incomplete combustion
Carbon Monoxide - ANSWERA dangerous byproduct of incomplete combustion of
natural gas
City Gate - ANSWERThe regulating station that reduces the pressure and measures of
the quantity of gas received from the distribution pipeline and prepares it for
consumption by the consumer by injecting a odorant into the gas stream
Combustion - ANSWERThe three requirements of combustion are fuel, oxygen, and an
ignition source
Compressor Station - ANSWERMachine that compresses the gas to a higher pressure,
to make up for the pressure drop through the length of the pipeline. Three types of
Compressor stations: Production, Storage, Transmission
Emergency Shutdown System (ESD) - ANSWERIn the event of an emergency situation,
such as leaking gas, the emergency shutdown system turns off the station and isolates
the pipeline by automated valves
Excess Flow Valve - ANSWERA valve inserted in a service line designed to shut off the
flow positively in the event its predetermined flow is exceeded
Heaters - ANSWERUsed during the processing of natural gas to keep gas from
temperature from falling below freezing to prevent ice ball formation on pipes and
condensation within pipes
Hydrocarbon - ANSWERThe combination of the elements hydrogen and carbon that
make up the basic elements of oil, natural gas, and coal
Ignition Temperature - ANSWERThe temperature at which a substance will ignite. The
ignition temperature of natural gas is about 1100F to 1200F
Meter - ANSWERA mechanical device which measures the volume of the gas delivered
from the operator to the customer. They are used at residential, commercial, and
industrial buildings that consume fuel gas supplied by a gas utility
Odorants - ANSWERNatural Gas has little or no odor and no color, so a odorant is
added to aid leak detection
GAS AND ABNORMAL OPERATING
CONDITIONS BASED ON STUDY
MANUAL NOT IN-CLASS CORRECT
100%
Range of flammability (definition) - ANSWERThe range which gas will burn. The range
of flammability for natural gas-air mixtures is approx. 5% to 15% natural gas
Regulating Station - ANSWERReduces the pressure and measures the quantity of gas
received from the distribution pipeline and prepares it by putting in odorants into the gas
stream for consumers.
Service Line - ANSWERA pipe that transports gas from a common source of supply to a
meter set assembly
Service Regulator - ANSWERA mechanical device that controls the flow of gas at a
constant pressure to meet downstream customers' demand. Standard delivery pressure
is normally 7 inches water column
Specific Gravity - ANSWERThe weight of gas compared to weight of air. The specific
gravity of natural gas is 0.6
Station By-Pass - ANSWERTakes over gas flow by maintaining it in the event of
emergency shutdown
Range of flammability (definition) - ANSWERThe range which gas will burn. The range
of flammability for natural gas-air mixtures is approx. 5% to 15% natural gas
Regulating Station - ANSWERReduces the pressure and measures the quantity of gas
received from the distribution pipeline and prepares it by putting in odorants into the gas
stream for consumers.
Service Line - ANSWERA pipe that transports gas from a common source of supply to a
meter set assembly
Service Regulator - ANSWERA mechanical device that controls the flow of gas at a
constant pressure to meet downstream customers' demand. Standard delivery pressure
is normally 7 inches water column
, Specific Gravity - ANSWERThe weight of gas compared to weight of air. The specific
gravity of natural gas is 0.6
Station By-Pass - ANSWERTakes over gas flow by maintaining it in the event of
emergency shutdown
Aldehydes - ANSWERA toxic substance formed from incomplete combustion
Carbon Monoxide - ANSWERA dangerous byproduct of incomplete combustion of
natural gas
City Gate - ANSWERThe regulating station that reduces the pressure and measures of
the quantity of gas received from the distribution pipeline and prepares it for
consumption by the consumer by injecting a odorant into the gas stream
Combustion - ANSWERThe three requirements of combustion are fuel, oxygen, and an
ignition source
Compressor Station - ANSWERMachine that compresses the gas to a higher pressure,
to make up for the pressure drop through the length of the pipeline. Three types of
Compressor stations: Production, Storage, Transmission
Emergency Shutdown System (ESD) - ANSWERIn the event of an emergency situation,
such as leaking gas, the emergency shutdown system turns off the station and isolates
the pipeline by automated valves
Excess Flow Valve - ANSWERA valve inserted in a service line designed to shut off the
flow positively in the event its predetermined flow is exceeded
Heaters - ANSWERUsed during the processing of natural gas to keep gas from
temperature from falling below freezing to prevent ice ball formation on pipes and
condensation within pipes
Hydrocarbon - ANSWERThe combination of the elements hydrogen and carbon that
make up the basic elements of oil, natural gas, and coal
Ignition Temperature - ANSWERThe temperature at which a substance will ignite. The
ignition temperature of natural gas is about 1100F to 1200F
Meter - ANSWERA mechanical device which measures the volume of the gas delivered
from the operator to the customer. They are used at residential, commercial, and
industrial buildings that consume fuel gas supplied by a gas utility
Odorants - ANSWERNatural Gas has little or no odor and no color, so a odorant is
added to aid leak detection
