RPZ Valve Testing in San Luis Obispo, CA
An RPZ, or reduced pressure zone assembly, protects the public water main from high-hazard connections: boiler feeds, chemical injection, car washes, medical and dental offices, and irrigation with fertilizer injection.
The test has three parts. First the tester checks that the relief valve opens at 2.0 psid or more. Then the first check is read, and it usually holds a differential of 5 psid or higher. Last, the second check is tested for tightness against backpressure.
A dripping relief port is the classic RPZ complaint. Most of the time a pebble or scale from a recent main break is holding the first check open. Sometimes the relief diaphragm itself has torn.
RPZ assemblies must sit above grade with open air under the relief port. One buried in a pit can flood and siphon dirty water back, which is why most codes forbid it.
Grizzly Backflow & Plumbing connects San Luis Obispo, CA property owners with testers who handle RPZ valve testing and backflow prevention paperwork for brands like Watts, Febco, Wilkins and Ames. Call (833) 990-5874.