Compressed natural gas (CNG) fuel storage and delivery systems for road vehicles

Note: The standard designation and scope for this NOI (originally published on April 13, 2023) were updated by the responsible SDO on February 27, 2024.

1.1 Applicability

This Standard applies to the design, installation, inspection, repair, and maintenance of the fuel storage and delivery system used as a provision for motive power. This Standard specifically addresses

1. on-road vehicles (highway vehicles);
2. off-road vehicles (mining and construction); and
3. powered industrial trucks (forklifts and TUGs).

Note: This Standard is intended to cover the fuel storage and delivery system as defined in Figure 1. Elements downstream of the regulation device(s) or stage(s) such as the low-pressure delivery line and injectors are not included in the Scope of this Standard.

1.2 Exclusions and future editions

1.2.1 Exclusions

This Standard does not apply to

1. stationary engines;
2. mobile equipment using natural gas as a fuel for other than propulsion;
3. electronic control module or controls strategy of a fuel management system;
4. storage or utilization of natural gas on marine vessels or rail vehicles;
5. liquefied natural gas (LNG) fuel storage systems; or
6. compressed natural gas (CNG) gaseous portion of LNG vehicles.

1.2.2 Future editions

Future editions of this Standard might include

1. LNG fuel storage system;
2. CNG portion of an LNG vehicle;
3. storage or utilization of natural gas on boats or trains;
4. recreational all-terrain vehicles; and
5. motorcycles.

1.3 Pressure references

All references to pressure throughout this Standard are to be considered gauge pressures, unless otherwise specified.

1.4 Canadian requirements

Annex G contains French translations for systems markings required for Canada.

1.5 Units of measurement

The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.

Notes:

1. IEEE/ASTM SI 10 or ISO 80000-1 can be used as a guide when converting US units to metric units.
2. Where the word “gallon” is used in this Standard, it indicates a U.S. gallon equivalent to 3.785 L water capacity.

1.6 Terminology

In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.