CNG Emergency Procedures and Response 5

Question 1

If a CNG fuel dispenser shows an unexplained pressure spike during a fueling operation, the operator should:

Accepted Answer

Stop fueling immediately and notify a supervisor

Answer

Unexplained pressure anomalies may indicate equipment malfunction or system failure; stopping fueling and notifying a supervisor prevents a potential incident.

Question 2

If a fire breaks out at a CNG compressor at a fueling station, the FIRST action should be:

Accepted Answer

Activate the emergency shutdown system and evacuate all personnel

Answer

The emergency shutdown (ESD) system cuts all gas flow and electrical power simultaneously; evacuation protects personnel while the system mitigates the hazard.

Question 3

The primary combined hazard when entering a confined space where CNG may be present is:

Accepted Answer

Oxygen-deficient atmosphere and potentially explosive gas concentration

Answer

CNG displaces oxygen in confined spaces creating asphyxiation risk, and accumulated gas within the 5–15% range creates an explosive atmosphere.

Question 4

A CNG fueling station should be evacuated immediately when:

Accepted Answer

A gas odor is detected anywhere on the premises

Answer

Gas odor indicates an active leak that could reach a flammable concentration; immediate evacuation removes personnel and eliminates potential ignition sources.

Question 5

Which type of communication device should NOT be used near an active CNG leak site?

Accepted Answer

Standard non-rated portable radios or consumer cell phones

Answer

Standard radios and cell phones can produce electrical arcs or sparks that may ignite a flammable gas-air mixture.

(CNG) Compressed Natural Gas Practice Test

(CNG) Compressed Natural Gas Practice Test

CNG Emergency Procedures and Response 5