Backflow Preventer Replacement in Phoenix

Most failed assemblies can be rebuilt, and that's where we start (see backflow assembly repair). Replacement is the right call in a few situations:

• Parts aren't available for an old or discontinued model.
• The body is damaged. Repair kits replace the moving parts, not a cracked or damaged body.
• It's the wrong type for the hazard. A double check on a site that needs an RP will never be compliant, no matter how well it tests.
• The city says it doesn't meet current standards. Tempe City Code 33-110 lets the department order an assembly retrofitted to current standards.
• It was stolen. That's its own job, covered on stolen backflow assembly replacement.

You don't get to pick the cheaper assembly. Arizona's rule, A.A.C. R18-4-215(E), sets the minimum by hazard, using the USC Manual. It ranks the options from most protection to least: air gap, RP, PVB, double check. Your water provider can always ask for more.

Mesa's code shows the logic plainly in a table (City Code 8-1-4). A double check covers non-health hazards, the "pollution" category. An RP covers health hazards, both backpressure and back-siphonage. So a building that only needs protection from water that's unpleasant but not dangerous can use a double check. A restaurant, medical office or anything on the cities' health hazard lists gets an RP.

Two rules follow from that:

1. 1Never downgrade. Swapping an RP for a double check because it's cheaper or doesn't dump water takes the site out of compliance.
2. 2Upgrading is usually fine. A higher level of protection is always allowed by the state rule, though the city still reviews it.

For the side-by-side, see RPZ vs double check.

The new assembly matches the service. Mesa and Scottsdale both require a diameter at least equal to the service connection. If the site runs two assemblies side by side so water stays on during tests, Scottsdale's rule is that their combined cross-sectional area at least equals the supply line (Revised Code 49-63(c)), so a replacement can't quietly shrink one leg. It also has to be an approved model. Phoenix's location guidance (TRT 00634) wants assemblies certified by the USC Foundation for Cross-Connection Control and Hydraulic Research or another third party ADEQ accepts.

A replacement is a good time to fix a bad location. An RP or double check in a meter box, pit or vault doesn't meet Phoenix City Code 37-144. Moving it is a relocation with its own approval, covered in backflow assembly relocation.

Phoenix's two documents don't line up perfectly, so we confirm before the job, not after.

Arizona's rule says an assembly can't go into service until it's tested and working as designed. So the new one gets its test the day it's installed. In Phoenix the report records the permit number and the serial number of the assembly it replaced, which is one more reason to keep old test reports. Mesa wants a retest within 24 hours of any replacement and the record in within seven days.

HQ replaces domestic backflow assemblies across the Valley: we pull the permit where the city requires one, set the correct type and size, test it and file the report with the city. Fire backflow assemblies and fire sprinkler work are outside what HQ does. We'll show you the failed test numbers and quote repair and replacement side by side when both are possible.

Free estimates for replacements, and an upfront price before work starts. Related: commercial backflow testing, commercial plumbing, medical and dental plumbing and restaurant plumbing.