ASSE 1013-26/CSA B64.4:26

Preface This is the first edition of ASSE 1013/CSA B64.4, Reduced pressure principle (RP) backflow prevention assemblies . It supersedes ASSE 1013, Performance Requirements for Principle Backflow Prevention Assemblies, published in 2021, and CSA B64.4, Reduced pressure principle (RP) backflow preventers, published in 2021. This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard. This Standard was prepared by the ASSE/CSA Harmonization Task Group on Reduced Pressure Principle Backflow Prevention Assemblies, under the jurisdiction of the ASSE Product Standards Committee and the CSA Technical Committee on Backflow Preventers and Water Pressure Reducing Valves. The CSA Technical Committee operates under the jurisdiction of the CSA Strategic Steering Committee on Construction and Civil Infrastructure. This Standard has been formally approved by the ASSE Product Standards Committee and the CSA Technical Committee on Backflow Preventers and Water Pressure Reducing Valves. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. This Standard was approved as an American National Standard by the American National Standards Institute. Scope 1.1 General This Standard covers reduced pressure principle (RP) backflow prevention assemblies (herein referred to as the "assembly") that are used in potable water supply systems to prevent cross-connections. 1.2 Sizes This Standard applies to nominal assembly sizes of 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2, 2, 2 1/2, 3, 4, 6, 8, 10, 12, 14, and 16 in (DN8, DN10, DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN150, D200, D250, D300, D350, and DN400). 1.3 Application RP assemblies are intended for use in the isolation of high or severe hazards where contaminated water can flow back into a potable water distribution system. 1.4 Description RP assemblies consist of two independently acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber (or zone) in which there is a hydraulically operated relief means for venting to the atmosphere, and internally force loaded to a normally open position. These assemblies are designed to operate under continuous pressure conditions. The assembly includes two properly located, tightly closing shut-off valves and properly located test cocks as per Clauses 4.4.4.5 and 4.4.4.4.1. 1.5 Terminology In this Standard, "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 (non-mandatory) to define their application. 1.6 Units of measurement SI units are the units of record in Canada. In this Standard, inch/pound units are shown in parentheses. The values stated in each measurement system are equivalent in application; however, each system is to be used independently. Combining values from the two measurement systems can result in non-conformance with this Standard. All references to gallons are to U.S. gallons.