How to Find Your Backflow Preventer’s Serial Number
Where the serial number sits on a backflow preventer, how to tell it from the model and size, and what to do when the tag is missing or unreadable.
Today’s backflow service took us to Brick Township, NJ, where we were called in to perform an annual backflow preventer test at a busy restaurant plaza. The property owner had multiple food establishments on-site, including a coffee shop, a pizza restaurant, and a seafood grill, all of which rely on a clean, safe water supply for cooking and cleaning.
The plaza’s main domestic water line is protected by an Apollo RP4A Reduced Pressure Zone Assembly (RPZ), which prevents contaminants—such as grease, cleaning chemicals, and food particles—from flowing back into the municipal system.
The RP4A was installed inside a mechanical room at the rear of the building. During our visual inspection, we noted:
We conducted a full backflow test using our differential pressure gauge:
Despite passing, the minor drip from the relief valve suggested that the internal rubber seating disc was wearing down.
To prevent future failure, we performed the following maintenance:
With the repairs completed, we retested the RP4A, and it continued to pass with optimal performance. We then:
Before leaving, we advised the property owner to:
Another successful job completed for South Jersey Backflow, ensuring the restaurant plaza can continue serving customers with a safe and clean water supply!
Where the serial number sits on a backflow preventer, how to tell it from the model and size, and what to do when the tag is missing or unreadable.
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