DCVA vs. RPZA Devices in New York City

Understanding Backflow Prevention

Backflow prevention is a critical aspect of maintaining a safe and clean water supply in any municipality, including New York City. As the city’s plumbing infrastructure continues to evolve, it’s essential to understand the differences between two commonly used backflow prevention devices: the Double Check Valve Assembly (DCVA) and the Reduced Pressure Zone Assembly (RPZA). In this blog post, we’ll explore the properties that require each type of backflow prevention device and delve into the reasons behind their selection.

1. The Basics of Backflow Prevention:

Before delving into the specifics of DCVA and RPZA devices, let’s briefly review why backflow prevention is crucial. Backflow occurs when non-potable water (contaminated or polluted water) flows back into the clean water supply, potentially endangering public health. Backflow prevention devices are designed to prevent this cross-contamination and ensure that the city’s drinking water remains safe for consumption.

2. Double Check Valve Assembly (DCVA):

DCVA devices are used to protect against low to moderate hazard cross-connections, where there is a potential for non-potable water to enter the clean water supply. Some properties in New York City that may require a DCVA device include:

Residential buildings with irrigation systems: If a residential building has an irrigation system connected to the municipal water supply, a DCVA device may be required to prevent any fertilizers or pesticides used in the landscaping from contaminating the drinking water.

Commercial buildings with fire sprinkler systems: Fire sprinkler systems are an essential safety feature, but they can introduce chemicals into the water supply if not properly protected. DCVA devices are often required to prevent backflow from fire sprinkler systems.

Industrial facilities with cooling systems: Facilities that use cooling towers or industrial processes involving non-potable water must install DCVA devices to prevent any potential contamination of the city’s water supply.

3. Reduced Pressure Zone Assembly (RPZA):

RPZA devices offer a higher level of backflow prevention and are used in situations where there is a high-risk potential for contamination. Properties in New York City that may require an RPZA device include:

Hospitals and medical facilities: These facilities often use hazardous chemicals and fluids, which could pose a significant risk to public health if they were to backflow into the water supply. RPZA devices provide an extra layer of protection in these environments.

Large commercial and industrial complexes: Properties with complex plumbing systems, such as factories and industrial plants, may require RPZA devices to safeguard against potential contamination from a wide range of processes.

High-rise buildings with multiple uses: Multi-purpose buildings that house various businesses, residential units, and amenities may need RPZA devices to prevent cross-contamination between different sections of the building.

4. Factors Influencing Device Selection:

The decision to install a DCVA or an RPZA device is influenced by several factors, including the type of property, the potential hazards involved, and local regulations. Plumbing professionals, building owners, and facility managers should work closely with certified backflow prevention experts to assess the level of risk and determine the appropriate type of device for each situation.


Backflow prevention is a critical aspect of maintaining a safe and clean water supply in New York City. Whether a property requires a Double Check Valve Assembly (DCVA) or a Reduced Pressure Zone Assembly (RPZA) device depends on the potential hazards associated with its plumbing systems. By understanding the differences between these devices and their applications, property owners and managers can contribute to the protection of public health and the environment, ensuring that the city’s water supply remains safe for all residents and businesses.

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