This Standard specifies requirements for the design, construction, operation and maintenance of compressed natural gas (CNG) refuelling stations, which can be one of the following:(a) fast fill, where vehicles are filled in a period of minutes, analogous to liquid refuelling;(b) time fill, where one or (in most cases) a number of vehicles are filled simultaneously over a period of some hours; or(c) a combination of fast fill and time fill.It does not cover equipment sizing and refuelling performance (the latter to be agreed between the purchaser and station constructor to suit the particular requirements of each station). This Standard does not cover the requirements for the following:(i) Liquefied Natural Gas (LNG) refuelling stations; or(ii) Vehicle Refuelling Appliances (VRA) installations, which are covered by AG 806.NOTES:1 Appendix D contains a checklist that provides guidance on the aspects of the station that should be checked prior to putting the station into service and during annual safety inspections.2 To the extent this Standard provides, in addition to minimum requirements, guidance in areas relating to the design and installation of CNG refuelling stations, such guidance should not be regarded as a design specification or an instruction manual.