CNG CNG Fleet Management and Driver Operations 2 — Questions and Answers
Question 1: A fleet manager scheduling preventive maintenance for CNG vehicles should ensure cylinders are re-inspected at which interval per NFPA 52?
- Every 3 years or per the cylinder manufacturer's specification, whichever comes first (Correct answer)
- Every 10 years regardless of condition
- Only when visible damage is observed
- At every oil change interval
Correct answer: Every 3 years or per the cylinder manufacturer's specification, whichever comes first
NFPA 52 requires periodic cylinder re-inspection at intervals specified by the manufacturer, typically every 3 years, to ensure continued safe service.
Question 2: When a CNG fleet vehicle is involved in a collision, what is the fleet manager's first safety priority regarding the fuel system?
- Close the manual shutoff valve and keep ignition sources away from the vehicle (Correct answer)
- Immediately restart the vehicle to check for warning lights
- Drain the cylinders by running the engine until empty
- Call the OEM before taking any action
Correct answer: Close the manual shutoff valve and keep ignition sources away from the vehicle
After a collision, the manual shutoff valve should be closed immediately to isolate the fuel supply and prevent gas release near potential ignition sources.
Question 3: Which training requirement is mandated for employees who fuel CNG vehicles at a fleet's private fueling station under OSHA standards?
- Hazard Communication (HazCom) training on compressed gas hazards and emergency procedures (Correct answer)
- CDL Class B licensing
- NFPA 1 Fire Inspector certification
- EPA-certified fuel economy testing
Correct answer: Hazard Communication (HazCom) training on compressed gas hazards and emergency procedures
OSHA's Hazard Communication Standard requires employees working with compressed gases, including CNG, to receive training on associated hazards and safe handling procedures.
Question 4: A fleet data system shows a CNG vehicle's average fuel consumption increased by 15% with no change in route. What is the most likely cause to investigate?
- A fuel system leak causing unaccounted gas loss (Correct answer)
- Improved driver behavior reducing idle time
- A faulty odometer reporting shorter distances
- Decreased fuel prices reducing cost tracking accuracy
Correct answer: A fuel system leak causing unaccounted gas loss
An unexpected increase in fuel consumption without route changes may indicate a slow leak in the CNG system that is wasting fuel.
Question 5: For a fleet operating CNG vehicles in cold climates, which operational challenge must managers plan for during winter months?
- Reduced fueling efficiency due to temperature-related pressure variations affecting fill levels (Correct answer)
- CNG cylinders freezing solid and becoming inoperable
- Natural gas turning to liquid inside the cylinders
- Increased NOx emissions in warm weather only
Correct answer: Reduced fueling efficiency due to temperature-related pressure variations affecting fill levels
Cold ambient temperatures affect gas density and pressure during fueling, which can reduce the amount of CNG that can be dispensed into cylinders without a slow-fill process.
Question 6: What telematics data point is most important for a CNG fleet manager to monitor in real time for safety compliance?
- Fuel system pressure readings and any low-pressure fault codes (Correct answer)
- Engine RPM during highway cruising
- Cabin temperature settings
- Infotainment system usage logs
Correct answer: Fuel system pressure readings and any low-pressure fault codes
Real-time fuel system pressure monitoring can detect anomalies that indicate leaks, regulator failures, or other safety-critical CNG system issues.
CNG CNG Fleet Management and Driver Operations 2
A fleet manager scheduling preventive maintenance for CNG vehicles should ensure cylinders are re-inspected at which interval per NFPA 52?