Backflow Prevention

Because the stakes are public health, backflow assemblies live in a world of rules: many jurisdictions require annual testing by certified testers, failed tests trigger repair deadlines, and installations must match the hazard level. This section covers testing, repair, installation and replacement of backflow assemblies.

• Backflow Preventer Installation
• Backflow Preventer Repair
• Backflow Preventer Replacement
• Backflow Testing

Signs a backflow assembly needs attention:

• Relief valve discharging. An RPZ relieving water, dripping or flushing, is doing its job while telling you a check or the relief valve itself needs service.
• Failed annual test. A failed test report is a service order: checks, springs or seats inside the assembly are not holding.
• Continuous or intermittent dripping. Fouled or worn internals; debris from line work is a classic trigger.
• Low flow or pressure downstream. A clogged or failing assembly throttles everything behind it.
• Noisy, chattering assembly. Checks slamming under fluctuating demand; wear accelerates from here.
• Freeze damage. Outdoor and above-grade assemblies crack in freezes; a split housing is a replacement, not a repair.

What actually goes wrong inside:

• Worn check valves and springs. Rubber and spring internals age on a known schedule, the reason annual testing exists.
• Debris fouling. Grit after utility work or line repairs lodges in the checks and holds them open.
• Pressure events. Backsiphonage (supply-side pressure loss) and backpressure (downstream pressure rise) are the two conditions assemblies exist to survive, and the events that reveal weak internals.
• Freezing. Water trapped in the body expands and cracks housings and relief valves.
• Wrong device for the hazard. A device rated below the hazard level (or installed in the wrong orientation or height) fails inspection regardless of its condition.

The work this section covers:

• Annual testing. Certified testing of RPZ, double-check and PVB assemblies with documented results filed where the jurisdiction requires them.
• Repair. Rebuild kits (checks, springs, seats, relief valve internals) restore most assemblies; a retest confirms the fix.
• Replacement. Cracked housings, obsolete models without parts, or repeated failures end in replacement matched to the hazard level and local approval lists.
• Installation. New assemblies for irrigation, fire lines, commercial equipment and multi-unit buildings: correct device class, orientation, clearances and drainage for relief discharge.

• Commercial Backflow Testing
• Water Pressure & Valves