Preface This is the first edition of CSA NGV 6.1, Compressed Natural Gas (CNG) fuel storage and delivery systems for road vehicles. Although this Recommended Practice provides recommended standard practices, it has been written in mandatory language to accommodate its adoption by anyone wishing to do so. This Recommended Practice was prepared by the NGV 6.1 Subcommittee on Compressed Natural Gas (CNG) Fuel Systems, under the jurisdiction of the Technical Committee on Natural Gas Powered Vehicles and Fuelling and the Joint Automotive Technical Committee. Scope 1.1 This Recommended Practice applies to the design, installation, inspection, repair, and maintenance of a fuel storage and delivery system installed in an on road vehicle for use with compressed natural gas (CNG). This includes a fuel system on a self-propelled vehicle for the provision of motive power. Note: This Recommended Practice 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 Recommended Practice. 1.2 This Recommended Practice does not apply to: a) stationary engines; b) mobile equipment using natural gas as a fuel for other than propulsion; or c) electronic control module or controls strategy of a fuel management system. Future editions of this Recommended Practice may 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) powered industrial trucks; e) off road applications including mining applications, all-terrain vehicles; and f) motorcycles. 1.3 OEM compressed natural gas vehicles and containers that have been qualified under the Canadian Motor Vehicle Safety Regulations or U.S. Federal Motor Vehicle Safety Standards (FMVSS) are exempt from the requirements in this Recommended Practice. 1.4 All references to pressure throughout this Recommended Practice are to be considered gauge pressures, unless otherwise specified. 1.5 This Recommended Practice contains SI (Metric) with corresponding English units, the purpose being to allow the Recommended Practice to be used in SI (Metric) units. American National Standard for Metric Practice, IEEE/ASTM SI 10, or ISO 80000-1, Quantities and units - Part 1: General, is used as a guide in making English conversion from metric units. If a value for a measurement and a corresponding value in 14other units are stated, the first stated value is to be regarded as the requirement. The given corresponding value may be approximate. If a value for a measurement and a corresponding value in other units are both specified as a quoted marking requirement, the first stated unit, or both, are to be provided. Where the word "gallon" is used in this Recommended Practice, it indicates a U.S. gallon equivalent to 3.785 liters water capacity. 1.6 In this Recommended Practice, "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; "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 Recommended Practice. 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.