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.