B64.10-17/B64.10.1-17

1.1 Application This Standard specifies requirements for the selection and installation of backflow preventers. Additional information on how backflow due to back siphonage and back pressure occurs, and how to select and apply specific devices, is included in Annexes A, B, and C. 1.2 Exclusions 1.2.1 This Standard does not specify requirements for materials, construction, or performance tests of backflow preventers. Such requirements are specified in the CSA B64 Series, in ASME A112.18.1/CSA B125.1, and in CSA B125.3. See Table 1. 1.2.2 This Standard does not specify requirements for maintenance or field testing after the initial installation. Such requirements are specified in CSA B64.10.1. 1.3 Terminology In CSA standards, “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 (nonmandatory) to define their application. 1.4 Measurement This Standard is written in SI (metric) units. For conversion tables, see Annex D. Vacuum is expressed in pressure below ambient.