CNG Cylinder Inspections
We have qualified cylinder inspectors on site to perform cylinder inspections.
CNG Cylinders - Compressed Natural Gas (CNG) cylinders are available in a number of different types, weights and sizes to suit different applications. As a general rule, as cylinder weight decreases, cylinder costs increase. In some cases, cylinders are available for lease from vehicle converters or gas suppliers. Details of cylinder suppliers can be found in our Business Directory (see left).
Cylinder types include:
- Type 1: This is an all metal - cylinder made of steel. There is no covering, other than paint, on the outside of the cylinder. This is the most common type of cylinder.
- Type 2: This is a metal cylinder (steel or aluminum) with a partial wrapping that goes around the cylinder. The wrapping is usually made of glass, aramid or carbon, contained in an epoxy or polyester resin.
- Type 3: This type of cylinder is fully wrapped with the same kind of material used for the partial wrapping of a Type 2 cylinder. This type of cylinder has a metal liner usually aluminum.
- Type 4: This type of cylinder is fully wrapped with the same kind of material used for the partial wrapping of a Type 2 cylinder. This type of cylinder has a plastic liner.
CNG Vehicle Fuel Container Standards - All CNG vehicle fuel containers MUST meet the federal government’s Federal Motor Vehicle Safety Standard (FMVSS) 304 (49 CFR 571.304), Compressed Natural Gas Fuel Container Integrity. All CNG vehicle fuel containers SHOULD meet American National Standards Institute (ANSI)/Canadian Standards Association (CSA) NGV2, Basic Requirements for Compressed Natural Gas Vehicle Fuel Containers. This industry standard is more comprehensive and up-to-date than FMVSS 304.
Label Requirements (S7.4, FMVSS 304)
“Each CNG fuel container shall be permanently labeled with the information specified in paragraphs (a) through (h) of this section.” ….“(g) The statement: ‘This container should be visually inspected after a motor vehicle accident or fire and at least every 36 months or 36,000 miles, whichever comes first, for damage and deterioration.’”
Periodic In-Service Inspection Requirements (Sec. 4.1.4, NGV2)
“Each container shall be visually inspected at least every 36 months, or at the time of any re-installation, for external damage and deterioration….The inspection shall be performed by a qualified container inspector in accordance with (1) the manufacturer’s recommendations and (2) the inspection procedures provided in Compressed Gas Association (CGA) pamphlet C-6.4”
