NGA 70 EXAM WITH COMPLETE SOLUTIONS 100%
VERIFIED!!
Matter
Anything that has weight and occupies space.
What is natural gas? - ANSWER>>Mix of gases, primarily methane. May include ethane,
propane, butane, CO2, hydrogen, and nitrogen
Specific gravity of air? What happens when specific gravity is higher or lower than that
of air? - ANSWER>>1
Higher SG sinks (Propane, gasoline, kerosene), Lower SG rises (Natural gas, carbon
monoxide)
What is Mercaptan? - ANSWER>>An odorant that is added to help detect leaks since
natural gas is odorless
5 physical characteristics of Natural Gas - ANSWER>>Matter, Weight, Nontoxic (but
displaces oxygen), Colorless, Odorless
Specific Gravity of Natural Gas, Carbon Monoxide, Air, Propane, Gasoline, Kerosene -
ANSWER>>NG- 0.6
CM- 0.98
Air- 1
Pro- 1.56
Gas- 3.5
Ker- 4.5
, Natural Gas is made up of what gases including % - ANSWER>>Methane- 90-95%
Ethane- 2-4%
Inert Gases- 2-4%
Propane- Less than 1%
Natural gas _______ when heated and ________ when cooled. - ANSWER>>-Expands
-Contracts
Gas temperatures will drop approximately ___ degree F for every ____ psig -
ANSWER>>1
14
3 elements of combustion - ANSWER>>-Fuel/gas to burn
-Oxygen
-Ignition source
When there is less than 5% NG in a NG and air mix it is referred to as too ____ to burn.
When there is more than 15% NG in a NG and air mix it is referred to as too ____ to burn -
ANSWER>>-Lean
-Rich
Natural Gas and air mix between ________% will burn. (Names for each end of the range)
- ANSWER>>5 and 15 (Lower and Upper Explosive Limit)
Complete Combustion - ANSWER>>-Blue flame
-Perfect mix of fuel/gas and oxygen resulting in combustion products of CO2 and water
Incomplete Combustion - ANSWER>>-Yellow flame
VERIFIED!!
Matter
Anything that has weight and occupies space.
What is natural gas? - ANSWER>>Mix of gases, primarily methane. May include ethane,
propane, butane, CO2, hydrogen, and nitrogen
Specific gravity of air? What happens when specific gravity is higher or lower than that
of air? - ANSWER>>1
Higher SG sinks (Propane, gasoline, kerosene), Lower SG rises (Natural gas, carbon
monoxide)
What is Mercaptan? - ANSWER>>An odorant that is added to help detect leaks since
natural gas is odorless
5 physical characteristics of Natural Gas - ANSWER>>Matter, Weight, Nontoxic (but
displaces oxygen), Colorless, Odorless
Specific Gravity of Natural Gas, Carbon Monoxide, Air, Propane, Gasoline, Kerosene -
ANSWER>>NG- 0.6
CM- 0.98
Air- 1
Pro- 1.56
Gas- 3.5
Ker- 4.5
, Natural Gas is made up of what gases including % - ANSWER>>Methane- 90-95%
Ethane- 2-4%
Inert Gases- 2-4%
Propane- Less than 1%
Natural gas _______ when heated and ________ when cooled. - ANSWER>>-Expands
-Contracts
Gas temperatures will drop approximately ___ degree F for every ____ psig -
ANSWER>>1
14
3 elements of combustion - ANSWER>>-Fuel/gas to burn
-Oxygen
-Ignition source
When there is less than 5% NG in a NG and air mix it is referred to as too ____ to burn.
When there is more than 15% NG in a NG and air mix it is referred to as too ____ to burn -
ANSWER>>-Lean
-Rich
Natural Gas and air mix between ________% will burn. (Names for each end of the range)
- ANSWER>>5 and 15 (Lower and Upper Explosive Limit)
Complete Combustion - ANSWER>>-Blue flame
-Perfect mix of fuel/gas and oxygen resulting in combustion products of CO2 and water
Incomplete Combustion - ANSWER>>-Yellow flame
