Mark: The Conbraco 4S-600 aka (DCDA4S) is a double check detector assembly. Production of this unit started in 1999. The 4S-600 utilizes a ½” model 4S-103 for the bypass device. Each access cover for mainline assembly is secured by bolts and sealed by a gasket. Before removing the check cover,...

Mark: The cam checks for this model normally should not be that difficult to remove. The thread pattern for each cam check is very large, so it would be nearly impossible to cross thread into the body. First let’s take a quick look at how the manufacturer instructs us to properly remove the checks....

Mark: The Wilkins model 450DA is a double check detector assembly. The 450DA series is unique because it is designed to be used in the “N” shaped configuration. This unit has a single access cover. The cover is secured by a grooved coupling and there is no spring load. Both check valves are modular...