Preface This is the third edition of CSA B108, Compressed natural gas fuelling stations installation code. It supersedes the previous editions published in 1999 and 1995. Scope 1.1 This Code applies to compressed natural gas fuelling stations that may be employed for fleet and public dispensing operations. 1.2 The scope of this Code does not include fuelling vehicles with liquefied natural gas (LNG). At LNG facilities that also include CNG vehicle fuelling, this Code applies only to facilities downstream of the isolation valve at the outlet of the natural gas vaporizer. 1.3 In this Code, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the code; "should" is used to express a recommendation or that which is advised but not required; "may" is used to express an option or that which is permissible within the limits of the code; and "can" is used to express possibility or capability. 1.4 All references to "kPa (psi)" throughout this Code are to be considered gauge pressures, unless otherwise specified. 1.5 This Code contains SI (Metric) units corresponding to the yard/pound quantities, the purpose being to allow the Code to be used in SI (Metric) units. If a value for a measurement and a corresponding value in other 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 shall be provided. Note: IEEE/ASTM SI 10 or ISO 80000-1 are used as a guide in making metric conversion from yard/pound quantities. Where the word "gallon" is used in this Code, it indicates a U.S. Gallon equivalent to 3.785 liters water capacity. Note: This code was developed originally using the imperial system of measurement and subsequently converted to metric units having three (3) significant digits. Every attempt has been made to provide accurate conversion values, When designing systems using these values engineering judgment needs to be applied.