CSA/ANSI NGV 4.8:21

1 Scope 1.1 Inclusions — Compressor packages This Standard describes the general requirements for compressor packages used in compressed natural gas fuelling station service. 1.2 Inclusions — Compressor designs This Standard applies to compressor designs referenced in Clause 5. 1.3 Pressure references All references to pressure throughout this Standard are to be considered gauge pressures unless otherwise specified. 1.4 Items unique to Canada Annex A contains items that are unique to Canada. 1.5 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. 1.6 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.