Preface This is the fourth edition of ANSI Z21.24 - CSA 6.10, Connectors for gas appliances. It supersedes the previous editions published in 2006, 2001, and 1997. Scope 1.1 This Standard applies to newly produced gas appliance connectors, constructed entirely of new unused parts and materials, having nominal internal diameters of 1/4, 3/8, 1/2, 5/8, 3/4, and 1 in, and having fittings at both ends provided with taper pipe threads for connection to a gas appliance and to house piping. This Standard covers assembled appliance connectors not exceeding a nominal length of 6 ft (1.83 m). Connectors listed under this Standard are intended for use with gas appliances that are not frequently moved after installation. For the purpose of this Standard, an unused connector, including end fittings, is considered to be a connector that has not been installed. 1.2 Appliance connectors complying with this Standard are considered suitable for use with natural, manufactured, mixed and propane gases, and LP gas-air mixtures. 1.3 Appliance connectors complying with this Standard are for use with piping systems having fuel gas pressures not in excess of 1/2 lb/in2 (3.5 kPa). 1.4 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. 1.5 All references to psi throughout this Standard are to be considered gauge pressure unless otherwise specified. 1.6 Annex A contains provisions that are unique to the United States. 1.7 Annex B contains provisions that are unique to Canada. 1.8 Clause 2 contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained. 1.9 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.