Backflow Testing Los Angeles: What Is a Double Check Valve Assembly (DCVA)?

A Double Check Valve Assembly—often called a DCVA or simply a “Double Check”—is one of the most common backflow prevention devices used to keep non-potable water from reversing direction and entering your clean water supply.

If you manage property in LA, understanding what a DCVA does (and what it doesn’t do) helps you stay compliant, reduce risk, and avoid costly surprises. This guide from Atlas Backflow Services explains how DCVAs work, where they should be installed, their limitations, and how Backflow Testing Los Angeles keeps your system safe year-round.

What a DCVA Does (and How It Works)

A DCVA is designed to prevent backflow caused by both backsiphonage (negative pressure pulling water backward) and backpressure (downstream pressure pushing water backward) under “low hazard” conditions.

A standard DCVA includes:

• Two spring-loaded check valves in series: If one check fails to seal, the second provides redundancy.

• Two shutoff valves: One upstream and one downstream for isolation during testing and maintenance.

• Four test cocks: Ports used by certified testers to measure differential pressure across each check.

How it works:

• Under normal flow, both checks open to allow water to move downstream.

• If pressure reverses, each check is designed to close, preventing backflow.

• Each check must maintain a minimum differential pressure (commonly 1.0 psid) to pass a certified test.

Key point: DCVAs do not have a relief valve, which makes them compact and versatile—but also limits their use to low-hazard applications.

Where DCVAs Are Appropriate in Los Angeles

Because they’re rated for “non-health hazards” (pollutants rather than contaminants), DCVAs are commonly used on:

• Commercial and residential irrigation systems without fertilizer injection or chemicals

• Fire sprinkler systems without additives or antifreeze (often a DCDA—Double Check Detector Assembly—for fire lines)

• General commercial services where substances pose a nuisance or system risk, but not an acute health hazard

• Booster pump or process lines where only low-hazard pollutants are present

If chemicals, dyes, medical waste, toxic substances, or reclaimed water are involved, you likely need a higher level of protection (typically an RP or RPDA). Not sure which device is correct? Atlas Backflow Services will review your site conditions and recommend the right assembly along with Backflow Testing Los Angeles to confirm compliance.

What a DCVA Is Not (Limitations You Should Know)

Choosing the wrong device can trigger violations. Be aware:

• Not for health hazards: If water could be contaminated with toxic substances, a DCVA is not sufficient. An RP-type device is typically required.

• Backsiphonage-only situations: For lines that only need backsiphonage protection and no backpressure risk, a PVB/SVB may be acceptable; your water provider determines what’s allowed.

• Flood-prone vaults: While DCVAs can be installed below grade in some jurisdictions, flooded vaults introduce failure risks and complicate testing. Many LA properties now prefer above-grade enclosures for accessibility and safety.

When in doubt, schedule a site assessment and Backflow Testing Los Angeles with Atlas Backflow Services. We’ll help verify the correct device, location, and protection level.

DCVA vs. DCDA vs. RP: Quick Comparison

• DCVA (Double Check Valve Assembly): Low hazard; protects against backsiphonage and backpressure. No relief valve. Compact footprint.

• DCDA (Double Check Detector Assembly): Same protection as DCVA but built for fire lines, with a bypass meter to detect unauthorized use/low flows.

• RP/RPDA (Reduced Pressure): For high/health hazards; includes a relief valve that discharges to atmosphere when internal pressure conditions signal a potential failure.

If your facility has additives in the fire system or chemicals in process water, an RP/RPDA is typically required. Atlas Backflow Services can evaluate each line and confirm the correct device before you invest in installation or replacement.

Installation Basics and Best Practices

For a long-lasting, compliant setup:

• Accessibility matters: Provide clear working space for valves and test cocks. Don’t block with landscaping or storage.

• Orientation and supports: Install in the manufacturer’s approved orientation with proper anchoring to avoid stress on piping.

• Above-grade enclosures: In many Los Angeles settings, insulated, lockable enclosures keep devices serviceable and protected from damage.

• Freeze and heat protection: Insulate where needed and avoid direct sun exposure that accelerates wear.

• Strainers and flushing: Upstream strainers reduce debris that causes check failures, especially after main breaks or construction.

Need help with layout or code questions? Atlas Backflow Services can coordinate installation details and provide Backflow Testing Los Angeles immediately after startup.

How Often to Test a DCVA in Los Angeles

In the Los Angeles area, water providers generally require:

• Testing at installation (or activation)

• Annual testing thereafter for each assembly

• Testing after repairs, relocation, or significant pressure events

This schedule applies to both DCVAs and DCDAs. Some facilities with sensitive operations may be placed on more frequent intervals by their water provider. We handle reminder schedules, testing, and report submissions—so you stay compliant without the paperwork hassle.

Signs Your DCVA Needs Service

Call for Backflow Testing Los Angeles if you notice:

• Pressure drops downstream that aren’t explained by normal demand

• Leaking around joints, test cocks, or shutoff valves

• Corrosion, mineral scale, or visible damage to the body or valves

• Irrigation zones acting erratically or failing to pressurize

• Frequent test failures in short intervals (may indicate internal wear or debris)

Many issues are fixable with a rebuild kit (seats, springs, seals). If the body is cracked, valves are seized, or parts are obsolete, replacement may be the smarter long-term move. Atlas Backflow Services can quote both repair and replacement so you can compare downtime and total cost.

Compliance Tips for Property Owners and Managers

• Keep records: Maintain copies of all test reports and repair documentation.

• Inventory devices: Large sites often have multiple assemblies (domestic, irrigation, fire, process). A master list avoids expired tests.

• Plan for access: Enclosures and clearances reduce service time and protect devices from damage.

• Respond to notices promptly: Water providers may send compliance reminders or deficiency letters—schedule Backflow Testing Los Angeles right away to avoid penalties.

Why Choose Atlas Backflow Services

Atlas Backflow Services specializes in residential and commercial Backflow Testing Los Angeles, including DCVAs, DCDAs, RPs, and RPDAs. With us, you get:

• Certified testers and calibrated equipment for accurate results

• On-the-spot repairs and retesting to minimize return visits

• Report management and submission per local provider requirements

• Device inventory, mapping, and annual reminders to simplify compliance

• Expert guidance on selecting the right assembly for your hazard level

Whether you’re a homeowner with an irrigation DCVA or a facility manager with multiple DCDAs and RPs, we keep your systems safe, documented, and compliant.

Conclusion

A Double Check Valve Assembly is a reliable, compact solution for preventing low-hazard backflow in many residential and commercial applications. It protects against backsiphonage and backpressure—but it’s not appropriate for health hazards, where an RP-type device is typically required.

Proper installation and annual Backflow Testing Los Angeles are the keys to dependable performance and regulatory compliance.Ready to confirm your device type, schedule a test, or solve a persistent issue?

Contact Atlas Backflow Services today. We’ll perform certified testing, provide clear pass/fail results, handle any repairs or replacements, and submit all required reports—so your water stays protected and your property stays compliant.