Choosing the right double check backflow preventer is essential for protecting potable water from contamination while meeting code requirements. This guide highlights practical options suited for different plumbing setups, from residential irrigation to commercial piping. The featured products focus on ease of maintenance, compact design, and reliability in non-health hazard applications. The top picks are best for DIY installers, facility managers, and contractors who need off-line servicing, quick flushing, or compact, modular configurations.
Summary of selected products
| Product | Best For | Key Benefit |
|---|---|---|
| Zurn Wilkins 1-350 1″ 350 Double Check Backflow Preventer | Residential or light commercial, inline installations | Off-line servicing and quick line flushing |
| Watts LF007 Series 2″ Lead-Free Copper Silicon Alloy Double Check | Continuous-pressure piping with NPT connections | Durable lead-free body, top test cocks, freeze sensor compatibility |
| Euluese 1-350 1″ Double Check Backflow Preventer | Off-line maintenance, outdoor installations | Removable pressure vessel, quick flushing, robust materials |
| Febco LF850 Series 1″ Lead-Free Copper Silicon Alloy Double Check | Small-diameter applications requiring modular design | Freeze sensor option, modular and serviceable |
| Zurn Wilkins 34-350 3/4″ 350 Double Check | Compact, smaller-line backflow prevention | Flush Tool and offline serviceability features |
Zurn Wilkins 1-350 1″ 350 Double Check Backflow Preventer
The 1-350 model from Zurn Wilkins is designed for non-health hazard applications in continuous-pressure piping. It uses a 1″ double check valve assembly with NPT connections and a compact, modular design. This unit is best for installers seeking a balance of reliability and serviceability in residential or small commercial lines. The flush tool feature helps with line flushing during installation, which can save time and reduce disruption. It is best for projects where quick maintenance and offline servicing are prioritized, and where water savings are a concern.
Who it is best for: small commercial facilities, multi-unit residential projects, and professional installers who want offline serviceability and efficient flushing.
Caution: Ensure correct sizing for the downstream line pressure to avoid unnecessary valve wear or flushing needs.
Watts LF007 Series 2″ Lead-Free Double Check
This Watts assembly uses a lead-free copper silicon alloy body with two independent check modules and captured springs. It features NPT connections, quarter-turn shutoffs, and top-mounted test cocks. The design supports continuous-pressure piping and helps prevent backflow due to back-siphonage or backpressure, making it suitable for non-health hazard services where reliability and standards compliance matter. A freeze sensor option adds monitoring insight for temperature-related risk.
Who it is best for: facilities that require durable, code-compliant backflow prevention with easy service access and potential freeze monitoring.
Caution: For outdoor installations in freezing climates, confirm sensor compatibility and optional hardware before purchasing.
Euluese 1-350 1″ Double Check Backflow Preventer
The Euluese 1-350 unit emphasizes off-line servicing with a removable pressure vessel, supporting quick maintenance. A flushing tool enables a single installer to flush lines quickly, with claimed labor savings over the life of the unit. Built from durable stainless steel and reinforced nylon, it is designed for outdoor use and harsh conditions. This model is best for operators prioritizing maintenance efficiency and robust construction.
Who it is best for: property managers, irrigation installers, and remote installations where offline servicing reduces downtime.
Caution: While the data shows significant labor savings, verify compatibility with your specific piping size and connection type before purchase.
Febco LF850 Series 1″ Lead-Free Double Check
The Febco LF850 mirrors the trusted lead-free copper silicon alloy design with a modular, quarter-turn shutoff and two independent check modules. It includes a top-mounted test cock assembly and captured springs for dependable seating. The system is described as freeze sensor compatible via SentryPlus, with optional monitoring to detect freezing conditions. The unit is well-suited for compact lines or rentals where a small-diameter backflow preventer is needed without sacrificing reliability.
Who it is best for: small spaces or retrofits in single-family or light commercial environments that require a compact, modular backflow preventer with potential sensor integration.
Caution: Confirm whether the optional freeze sensor kit is needed for your climate and monitoring setup.
Zurn Wilkins 34-350 3/4″ 350 Double Check
This 3/4″ version from Zurn Wilkins packs line-flushing with a flush tool, aiding quick maintenance during installation. The design is compatible with offline serviceability and water-saving features. It is a compact option for smaller lines while maintaining the reliability expected from the Wilkins line. It is best for space-constrained applications where quick flushes and offline servicing are beneficial.
Who it is best for: installers working on tight spaces or small irrigation feeds that still require robust backflow protection.
Caution: The 3/4″ size may not suit larger service lines—verify your piping diameter before selecting.
Wilkins 1-350FT Double Check Composite Vessel
The Wilkins 1-350FT features a composite vessel with Fnpt connections and fast test cocks. This model is suited for installations that benefit from quick testing and straightforward maintenance. It provides a straightforward, compact option for medium-duty backflow prevention needs. The composition emphasizes ease of testing and replacement parts while keeping the footprint small.
Who it is best for: contractors and facility operators who value quick test access and a compact footprint for 1″ lines.
Caution: Confirm availability of replacement parts for the composite vessel model in your region to minimize downtime.
Buying Guide: Key Considerations for Double Check Backflow Preventers
- Application and code requirements: Identify whether you need a device for non-health hazard applications and confirm local code compliance for your area and project type.
- Size and connection type: Match the valve size (1″, 3/4″, or larger) to your piping. Check connection types (NPT, FNPT, etc.) to ensure compatibility with existing hardware.
- Serviceability: Consider offline servicing capabilities, removable pressure vessels, and flush tools. These features reduce downtime during maintenance and installation.
- Materials and durability: Lead-free copper silicon alloy bodies offer corrosion resistance and durability. For outdoor installations, consider UV resistance and weather tolerance of nylon-reinforced parts.
- Testing and instrumentation: Look for top-mounted test cocks and easy, field-accessible testing options. Some models include quick-test features or integrated sensors for temperature monitoring.
- Freeze protection: If your climate experiences freezing temperatures, a model with a freeze sensor option or compatible monitoring can prevent service interruptions.
- Maintenance costs and labor: Flushing tools and removable vessels can reduce maintenance time and labor costs over the life of the unit. Weigh upfront cost against long-term savings.
FAQ
- What is a double check backflow preventer used for?
It prevents backflow in piping to protect the potable water supply from contamination due to back-siphonage or backpressure in non-health hazard applications.
- Which size should I choose for a residential irrigation line?
Common sizes are 3/4″ and 1″. Choose based on your main line diameter and flow requirements, ensuring compatibility with existing fittings.
- Do backflow preventers require regular maintenance?
Yes. Regular testing, flushing, and occasional replacement of seals or springs help maintain effectiveness and compliance with code requirements.
- Is a freeze sensor worth the extra cost?
For climates with freezing temperatures, a freeze sensor can prevent damage and service disruption by signaling when temperatures are near freezing.
- Can I install a backflow preventer myself?
Installation should follow local code and manufacturer instructions. Some devices offer offline servicing that simplifies field maintenance, which can be helpful for DIY projects but professional installation is often recommended for critical systems.
- What maintenance tool features are most beneficial?
Flush tools, top-mounted test cocks, and removable pressure vessels reduce maintenance time and downtime, especially on larger or remote installations.