RPZA vs. DCVA: What's the Difference?
Understanding the Difference Between RPZA and DCVA Can Save You Time and Money
If you're looking into backflow preventers, you've probably come across the terms RPZA (Reduced Pressure Zone Assembly) and DCVA (Double Check Valve Assembly). While they may sound like technical jargon, the difference between the two is actually pretty straightforward—and important. Both devices prevent contaminated water from flowing back into your clean water supply, but they do so in different ways and are used in different situations depending on the level of hazard present.
RPZAs Offer the Highest Level of Protection for High-Risk Systems
RPZAs are designed to handle high-risk scenarios—think commercial properties, medical facilities, or anywhere chemicals or pollutants might enter the system. They use a special relief valve between two check valves that actively discharges water if pressure drops or if one valve fails. This added safety feature makes them ideal for protecting against serious contamination risks. However, because of this design, they must always be installed above ground and in areas where the relief valve can safely discharge water without causing flooding or damage.
DCVAs Are Reliable for Moderate-Risk Situations and Underground Installations
On the other hand, DCVAs are a great choice for lower- to moderate-risk systems, like standard irrigation setups or residential fire sprinkler systems. They also have two check valves but don’t include a relief valve—making them more compact and suitable for underground installations. While they still offer solid protection, they’re not designed for highly hazardous conditions. Knowing which device is right for your property comes down to the potential level of contamination. By understanding the strengths of each, you’ll make a smarter, safer choice for your water system.
Planning for the Future: Why an RPZA May Be the Smarter Long-Term Choice
For property owners with buildings that may change use over time—such as switching between residential (low-risk) and commercial (high-risk) purposes—it’s often smarter to plan ahead by installing an RPZA from the start. While a DCVA might be sufficient for a residential setup, it won't meet code requirements if the property's use shifts to something like a restaurant, medical office, or any business involving chemicals. Upgrading later can be more expensive and disruptive, requiring excavation or re-plumbing. Installing an RPZA upfront offers long-term flexibility and ensures compliance no matter how the property is used in the future, saving time, money, and headaches down the line.
Choosing the Right Backflow Preventer Depends on Your Specific Needs
In short, both RPZAs and DCVAs are valuable tools for keeping your water supply safe, but they serve different purposes. RPZAs are the go-to choice for high-hazard situations where maximum protection is required, while DCVAs are reliable and cost-effective solutions for moderate-risk applications. Understanding these differences helps ensure you're compliant with local regulations and that your property—and its occupants—stay protected. When in doubt, consult with a certified backflow specialist to determine which device best fits your system’s needs.