CSA ANSI NGV 6.1:21

Preface 

This is the third edition of CSA/ANSI NGV 6.1, Compressed natural gas (CNG) fuel storage and delivery systems for road vehicles . It supersedes the previous edition published in 2018. The first edition of CSA/ANSI NGV 6.1 was a Recommended Practice that provided a recommended standard practice for vehicle fuel systems. It was written in mandatory language to accommodate its adoption by anyone wishing to do so. The second edition transitioned to a National Standard. CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada. This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It will be published as a National Standard of Canada by CSA Group. 

Scope 

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 a) On-road vehicles (highway vehicles); b) Off- road vehicles (mining and construction); and c) 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 a) stationary engines; b) mobile equipment using natural gas as a fuel for other than propulsion; c) electronic control module or controls strategy of a fuel management system; d) storage or utilization of natural gas on marine vessels or rail vehicles; e) liquefied natural gas (LNG) fuel storage systems; or f) compressed natural gas (CNG) gaseous portion of LNG vehicles. 

1.2.2 Future editions Future editions of this Standard might include a) liquefied natural gas (LNG) fuel storage system; b) compressed natural gas (CNG) portion of an LNG vehicle; c) storage or utilization of natural gas on boats or trains; d) recreational all-terrain vehicles; and e) motorcycles. 

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

1.4 Units of measure 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 Imperial units to metric units. 2) Where the word "gallon" is used in this Code, it indicates a U.S. gallon equivalent to 3.785 liters water capacity. 

1.5 Mandatory and informative provisions 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 existing codes and this 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.