USC Foundation

List of Approved Backflow Prevention Assemblies

Updated 4/1/2024


The Double Checked Detector Assembly(DCDA) and Reduced Pressure Principle Detector Assembly(RPDA) contained here in have been evaluated with a specific meter as the detector meter of the assembly. The specific meter is coded by a parenthetic letter shown in the "meter" column. The coding of meter is shown in the section. Other meter having similar performance characteristics to permit the assembly to meet the Specifications are shown immediately after the original evaluation meter. The use of any other meter or modified bypass piping invalidates the Approval.

Some of the DCDA's and RPDA's utilize a line-size assembly, which is not a stabdard or stock Approved assembly. Increased load are required in this line-size unit to allow the assembly to accurately record low flow rate in the bypass meter. Therefore, various 'off the self' components can not be assembled expected to perform satisfactorily. The bypass backflow preventer approved with the detector assembly is listed under the "bypass" column. This is only for verification purposes. Should replacement pass or a complete by-pass be needed the model number of the complete detector assembly should be used in ordering these components.