CSA B356:22

1 Scope 1.1 General This Standard applies to self-acting spring-operated devices that automatically reduce the initial pressure in water systems to a set lower pressure. It applies to devices that are of the direct-acting diaphragm type with a means for adjusting the pressure setting. Valves can be with or without an integral bypass relief valve or strainer. 1.2 Sizes This Standard applies to nominal device sizes of 1/4, 3/8, 1/2, 3/4, 1, 1-1/4, 1-1/2, 2, 2-1/2, 3, and 4 in (DN 8, DN10, DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, and DN100). 1.3 Requirements This Standard provides requirements for material specifications, construction, structural integrity tests, capacity, reduced pressure deviations, instructions, and marking. 1.4 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. 1.5 Units of record The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.