Changes to CNG cylinder inspection intervals required by the U.S. Department of Transportation’s Federal Motor Vehicle Safety Standard (FMVSS) No. 304, “Compressed natural gas fuel container integrity,” were published in the Federal Register February 11, 2022, and become effective March 13, 2022. The compliance date is March 14, 2023, but early compliance is permitted.
The change specifically applies to medium- and heavy-duty CNG-powered vehicles with a gross vehicle weight rating (GVWR) of 10,000 pounds or greater.
The revised requirements for CNG cylinder inspections are as follows:
- All CNG cylinders must be inspected after any fire or accident, regardless of vehicle GVWR.
- For vehicles with GVWR of less than 10,000 pounds, CNG cylinders must be inspected at least every 3 years or 36,000 miles, whichever comes first.
- For vehicles with GVWR of 10,000 pounds or greater, CNG cylinders must be inspected at least every 12 months.
This revision lessens the burden on heavy-duty CNG fleet operators. It also aligns the CNG inspection interval with the Federal Motor Carrier Safety Administration’s (FMCSA) Annual Vehicle Inspection interval, although the two inspections are very different.
While the new intervals apply specifically to CNG cylinders, NGV industry best practice calls for inspection of the entire CNG fuel system.