Preface This is the fourth edition of ANSI Z21.69 / CSA 6.16, Connectors for moveable gas appliances . It supersedes the previous editions published in 2009, 2002, and 1997. Scope 1.1 This Standard applies to newly produced gas appliance connectors constructed entirely of new, unused parts and materials that are intended for use with gas utilization equipment that may be mounted on casters or otherwise be subject to movement. 1.2 Connectors complying with this Standard are considered suitable for use with natural, manufactured, mixed and propane gases, and LP gas-air mixtures. 1.3 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. 1.4 All references to psi throughout this Standard are to be considered gauge pressure unless otherwise specified. 1.5 Annex A contains provisions that are unique to Canada. 1.6 Clause 2 contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained. 1.7 In this Standard, \"shall\" is used to express a requirement, i.e., a provision that the user shall 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.