NGA 70 Properties of Natural Gas and Abnormal Operating Conditions Practice Test

These questions are part of the practice quiz. Start practicing

• How is the compressibility factor Z applied in gas flow calculations?
• How does abnormal pressure affect pipeline integrity?
• What is the primary reason for designing for sour gas service?
• What measures are used to manage H2S hazard in natural gas handling?
• What is an odorant, and why is it added to natural gas?
• Why is controlling hydrocarbon dew point important in natural gas pipelines?
• What consequence can hydrocarbon liquids cause in pipelines if dew point is high?
• Which statement best describes natural gas flow relative to pressure?
• What types of instrumentation detect abnormal operating conditions such as leaks or fires?
• What is hydrocarbon dew point and why is it important for pipelines?
• What is the specific gravity of propane?
• What is the function of relief devices in natural gas systems?
• Gas analysis data are used for quality control and what calculations?
• What action may be required if deviations exceed composition tolerance?
• The three requirements of combustion are fuel, oxygen, and an ignition source. Which term describes this process?
• What is the purpose of an Emergency Shutdown (ESD) system in gas pipelines?
• In dehydration planning for natural gas, which condition is most likely to be addressed?
• What is the practical difference between scf and Nm3 for gas measurement?
• How does water dew point differ from hydrocarbon dew point in natural gas?
• Compared with air, is propane heavier or lighter?
• What is the primary purpose of gas dehydration in pipelines?
• What is a Station By-Pass used for?
• Which statement best describes a consequence of hydrate formation in pipelines?
• What happens when gas in a buried pipe falls below freezing (32 F)?
• Which health and safety considerations are essential when dealing with sour gas in a pipeline environment?
• What is the purpose of volume corrections to standard conditions in gas measurement?
• What is a gas chromatograph used for in natural gas analysis?
• Which instrument provides precise composition data used in quality control?
• How often must the manual be reviewed and updated?
• What term refers to the combination of hydrogen and carbon that make up the basic elements of oil, natural gas, and coal?
• What is odor fade, and what factors can contribute to it?
• Which regulation requires operators to establish written procedures to minimize hazard from a gas pipeline emergency?
• Which equipment compresses gas to a higher pressure to compensate for pressure drop along the pipeline?
• How do pressure and temperature influence natural gas phase behavior?
• What is the specific gravity of air?
• Which hydrocarbon has an ignition temperature of 806°F?
• Which factor most contributes to frost heave around buried pipelines?
• What is the typical specific gravity of natural gas?
• Which standard volume and energy units are commonly used for natural gas properties?
• What is the impact of CO2 on natural gas quality and pipeline integrity?
• Which of the following is NOT a factor affecting escaping gas migration?
• In natural gas combustion, how can nitrogen dilution affect the flame?
• Which term describes the process that requires fuel, oxygen, and an ignition source to occur?
• Which factor is included in the properties of escaping gas?
• Which component introduces odorants into the gas stream before it reaches consumers?
• If frost heave lifts the pipe causing misalignment, what's a likely consequence?
• Which effect of freezing soil is most directly associated with stress on a buried gas pipe?
• What is the function of a gas chromatograph in gas testing?
• What does 'gas quality vs. gas specification' refer to in pipeline operations?
• Which option best describes the physical characteristics of natural gas?
• Activation of a Safety Box and other listed items belong to which AOC category?
• What does the compressibility factor Z do in natural gas calculations?
• Which device measures the volume of gas delivered from the operator to the customer?
• When reporting an accident, who do you notify and what minimal information should be provided?
• Subfreezing soil around buried natural gas line can lead to which outcome?
• Incomplete combustion in gas burners can produce which hazardous byproducts?
• Under what condition would a gas detector alarm indicate an abnormal operating condition?
• What does the Specific Gravity of natural gas describe?
• Where in the domestic gas appliance do gas and air mix together?
• Which design feature helps a buried gas pipeline tolerate frost-related movement?
• What is the lower limit of natural gas in the flammable range?
• Which statement about joints and gaskets in sour gas service is correct?
• The most common indication of a gas leak is
• Ignition temperature of gasoline, kerosene, and fuel oil is approximately which temperature?
• When propane, gasoline, or fuel oils are released into the atmosphere, where do they settle and accumulate near?
• Is frost-related stress always harmful, or can it be accommodated?
• Ignition Temperature of Butane
• What mechanism causes stress when soil freezes around a buried gas pipe?
• What is the approximate range of flammability for natural gas in air?
• If gas is leaking from a pipeline under frozen soil, the gas typically migrates in which directions?
• Which component maintains gas flow during an emergency shutdown?
• Slugging in a natural gas pipeline can cause which issues?
• Why is dehydration important before pipeline transport of natural gas?
• What affects the distance and/or rate of migration of escaping gas?
• Natural Gas flows from area of _____ to one of _______.
• What is hydrate formation and under what conditions does it occur?
• What valve is inserted in a service line to shut off flow when predetermined flow is exceeded?
• Which item is not part of the minimal information required when reporting an incident?
• Missing valve or curb box covers, open or damaged vaults, unexpected contents in a pipeline, and failure to comply with company standards are considered which type of condition?
• What is the function of a pressure regulator in a gas distribution system?
• Gas composition data from testing is used for which calculations?
• Which factor promotes hydrate/condensed phase formation in gas pipelines?
• Which regulation requires a continuing public education program following API RP 1162?
• How is Abnormal Operating Condition defined?
• Which term is a dangerous byproduct of incomplete combustion of natural gas?
• In sour gas service design, what combination of materials is typical?
• In a natural gas utility system, which component measures the volume of gas delivered from the operator to the customer?
• What is the primary purpose of odorization in natural gas?
• What is the specific gravity of gasoline?
• Which category covers overpressure, underpressure, and no pressure in AOC terms?
• Which outcome results directly from removing moisture in the gas stream?
• The specific gravity of natural gas relative to air is approximately what value?
• Odor fading may be caused by absorption of the odorant into which component?
• Issues first noticed by customers such as complaints or odorization fall under which AOC category?
• If not enough air is supplied to the gas burner, incomplete combustion will occur, resulting in the increased formation of
• Which of the following is a potential cause of gas system overpressurization?
• Which term refers to the regulating station that reduces pressure and measures gas from the distribution pipeline and prepares it for consumption by injecting an odorant?
• Ignition Temperature refers to the temperature at which a substance will ignite. Which term is used for this concept?
• The standard delivery pressure for service regulators is normally what value?
• Which sign would most clearly indicate frost-related exterior loading on a buried pipe?
• Which instrument is used to separate and quantify gas components for quality control in natural gas?
• Which substance among the listed has the highest specific gravity?
• What is required for combustion of natural gas to occur?
• True or False: Natural Gas mixed with air below 5% is considered flammable.
• At what soil temperature does frost formation become a concern for buried pipelines?
• Maintenance action to prevent damage from frost?
• Why is an odorant added to natural gas?
• For transmission lines, what must the manual include in addition to other procedures?
• Which condition affects the migration of escaping gas?
• Mercaptan is used in natural gas to provide which odor?
• The Public Awareness Program guidance is provided by which API Recommended Practice?
• What system turns off the station and isolates the pipeline during an emergency by automated valves?
• Which design feature helps a buried gas pipeline tolerate frost-related movement?
• Water dew point is defined as the temperature at which water condenses; why is it important in natural gas pipelines?
• How does material selection affect sour gas service?
• Which term is defined as a toxic substance formed from incomplete combustion?
• Which statement about CO2 in natural gas is true?
• What is the role of remote valve actuation in an AOC?
• Which option best describes the physical characteristics of natural gas?
• What is the primary mixture of natural gas?
• What is the primary reason frost around buried pipe stresses it?
• In the typical AOC gas leak response sequence, which step comes last?
• In an AOC, what is the typical sequence when a gas leak is suspected?
• How does temperature influence gas density and volume?
• What is the primary purpose of the Wobbe Index in natural gas systems?
• What is sour gas, and what precautions does it necessitate?
• How does temperature control help prevent hydrate formation in pipelines?
• Gas migration is influenced by soil conditions including which of the following?
• Which statement best describes why dehydration is essential for preventing ice-related flow issues?
• Activation of a Safety Box is categorized under which AOC?
• What is the upper limit of natural gas in the flammable range?
• What is a common AOC scenario involving odorants?
• What is a Service Line?
• What is used to mitigate moisture-related issues in natural gas pipelines?
• Which regulation requires steps to minimize danger of accidental ignition in structures or areas with gas hazard?
• Ignition Temperature of Propane
• Which regulation defines Abnormal Operating Condition in the regulatory definitions?
• Why is odorization used in natural gas, and what challenge can cause odor fade?
• What safety concerns arise from cross-contamination of gas streams in processing facilities?
• Provide the standard formula for Wobbe Index.
• What is the ignition temperature of natural gas typically cited as?
• Which of the following are potential causes of overpressurization?
• Which statement defines an Abnormal Operating Condition (AOC)?
• How is natural gas's molecular weight used to compute its relative density to air?
• What equipment is used during natural gas processing to keep temperature from dropping below freezing and prevent ice formation in pipes?
• Why are corrosion-resistant alloys important in sour gas service?
• What is the primary purpose of odorants in natural gas?
• Which statement correctly describes the standard conditions used for Nm3 measurements?
• What is a typical method for communicating emergency notices and isolating a facility during an AOC?
• Which statement best describes the effect of abnormal pressure on gas pipelines?
• Which corrections are applied to convert gas volumes to standard conditions?
• Relative density is used in gas operations and leak detection to...
• What practice helps mitigate frost-related thermal stress by controlling moisture and soil movement?
• Odor fading can be caused by absorption of the odorant into which component?
• Why monitor the Wobbe Index rather than HHV alone in system design?
• What is the machine that compresses gas to a higher pressure to make up for pressure drop along the pipeline?
• Which statement correctly describes low-pressure leaks compared to high-pressure leaks?
• Odor fading may be caused by chemical instability of the odorant or
• Why are gas composition analyses performed at the wellhead or processing plant?
• How does nitrogen in natural gas affect energy content and combustion?
• What is the specific gravity of kerosene/fuel oil?
• In sour gas service, why must materials resist H2S/CO2 corrosion?
• What does AOC stand for in gas pipeline context?
• Which of the following best summarizes the factors that influence gas migration path and concentration?
• What is the specific gravity of carbon monoxide?
• The stress from freezing soil around a pipe is most likely to cause which mechanical issue?
• What does a service regulator do?
• Define Lower Explosive Limit (LEL) and Upper Explosive Limit (UEL) in the context of abnormal operating conditions.
• The presence of ______ in natural gas distinguishes it from other combustible gases or gases from decaying material, such as sewer gas.
• What does composition tolerance mean in natural gas pipelines?
• Unmarked facilities, Natural Disaster, Fire, or Explosion(s) are categorized under which AOC?
• What odor is commonly used to indicate natural gas leaks?
• Which term is defined as the regulation station that reduces pressure and measures gas from the distribution pipeline and injects odorant?
• Which tasks are performed by a regulating station?
• When a high H2S concentration is detected, which is best practice?
• What does the term 'sweet gas' mean and what impurity levels characterize it?