NGA 70 & 71 PROMETRICS (ACTUAL 2025/2026) STUDY SET WITH QUESTIONS AND ANSWERS

NGA 70 - AOCS & PROPERTIES OF NATURAL GAS (ACTUAL
2025/2026) QUESTIONS AND ANSWERS.




Fuel or gas to burn, oxygen in the air to react, ignition source
 Combustion elements




Natural Gas and air mixtures, lower than 5% natural gas will
not burn




Natural Gas and air mixtures, of approximately 5%-15% natural
gas will
burn




Natural gas and air mixtures, higher than 15% will
not burn, but are considered hazardous atmospheres




Complete combustion results in
water and carbondioxide

, Incomplete combustion results in
by-products including carbon monoxide and aldehydes




A yellow flame on the normal gas burner indicates
burner is out of adjustment or air, may result in carbon
monoxide




Incomplete combustion is occurring and the appliance is not
properly vented causes
sharp pungent odor indicating the presence of aldehydes




If aldehydes are present, most likely this chemical is too
carbon monoxide




Immediately evacuate the building, eliminate all sources of
ignition, seek assistance from appropriate company personnel
to ventilate the building
Preventing Ignition of Combustible Gas