CNG Fueling Station Operations 3

Question 1

If a CNG fire ignites at a fueling station, what is the FIRST recommended action?

Accepted Answer

Activate the emergency fuel shutoff and evacuate the area

Answer

The first priority in a CNG fire is activating the emergency shutoff to cut fuel supply, followed by immediate evacuation and calling 911 — extinguishing a gas fire without stopping flow creates an explosive cloud.

Question 2

What is the lower explosive limit (LEL) of natural gas (methane) in air?

Accepted Answer

5%

Answer

Methane's LEL is approximately 5% by volume in air; below this concentration, the mixture is too lean to ignite.

Question 3

Which NFPA code is the primary national standard for CNG vehicular fueling system safety?

Accepted Answer

NFPA 52

Answer

NFPA 52, Vehicular Natural Gas Fuel Systems Code, is the primary standard covering CNG fueling station design, installation, and operational safety.

Question 4

At what percentage of the LEL should a fixed combustible gas detector alarm at a CNG station?

Accepted Answer

20% LEL

Answer

Industry practice sets alarm thresholds at 20% LEL to provide early warning well before gas concentrations reach an ignitable range.

Question 5

What type of portable fire extinguisher is most appropriate for use at a CNG fueling station?

Accepted Answer

Dry chemical ABC-rated extinguisher

Answer

ABC dry chemical extinguishers are appropriate at CNG stations because they handle ordinary combustibles, flammable gases/liquids, and energized electrical equipment.

(CNG) Compressed Natural Gas Practice Test

(CNG) Compressed Natural Gas Practice Test

CNG Fueling Station Operations 3