Precautions while using CNG
Welding And Hot Work Precautions
For any welding in or near a CNG storage
system, consider the following
1. Ensure the vehicle is in a well ventilated
area. Do not park the vehicle in an area
where natural gas may accumulate.
2. Turn all cylinder shutoff valves to the
3. Make sure the manual shutoff valve on
the FMM is turned to the ON
4. Turn on the vehicle and run the engine
until it stops.
5. Ensure the vehicle is off and proper
vehicle lock out procedures have been
followed. Remove ignition key.
6. Check gauges on FMM to ensure all
pressure has been relieved.
7. Remove access cover to fill panel.
8. Slowly relieve excess pressure using the
9. The system is now fully depressurized
up to the primary solenoid lock off
valve. There may be residual pressure
downstream of the solenoid valve.
10. To remove gas downstream of the
primary solenoid lock off valve,
disconnect the electrical connector
from the fuel panel and use a 12V or
24V power source as the vehicle
requires to activate open the
solenoid lock off valve.