CSA ANSI HGV 4.5:23

Preface 

This is the second edition of CSA/ANSI HGV 4.5, Priority and sequencing equipment for hydrogen fuelling stations. It supersedes the previous edition published in 2013. The following are the major changes to this edition: a) reorganization of content to ensure consistency with current CSA editorial practices; and b) harmonization with other hydrogen fuelling documents. This Standard is considered suitable for use for conformity assessment within the stated scope of the 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 was prepared by the Subcommittee on Hydrogen Dispensing Systems, under the jurisdiction of the Technical Committee on Hydrogen Transportation and the Strategic Steering Committee on Transportation, and has been formally approved by the Technical Committee. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard. 

Scope 

1.1 Inclusions 

This Standard applies to priority and sequencing equipment used in compressed gaseous hydrogen fuelling stations and specifies general, materials, construction, and assembly requirements. 

1.2 Exclusions 

This Standard does not apply to equipment already covered by CSA/ANSI HGV 4.9. 

1.3 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. 

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.