Zurn 1-420XL Lead-Free Pressure Vacuum Breaker Assembly with Integral Anti-Freeze Relief Valve

The Zurn Wilkins 1-420XL is a 1" lead-free pressure vacuum breaker with FNPT connections, approved for high health hazard protection. It features a stainless body. Rated to 175 psi and up to 140°F. This model is certified lead-free for potable-water installations.

The 420XL Pressure Vacuum Breaker Assembly is used for high health hazard, residential irrigation and potable water applications for protection against backsiphonage of contaminated water into the potable water supply. The 420XL is equipped with an internal, integral anti-freeze relief valve to reduce the risk of costly valve damage in intermittent, non-seasonal freezing conditions. It is best used under continuous pressure, and features a modular design to reduce repair time and costs. Its low-lead cast bronze main valve body and 300 series stainless steel springs effectively resist corrosion.

Features

• Modular design elements ease repair costs and time
• Integral anti-freeze relief valve provides light freeze protection
• Cast bronze body and stainless steel springs resist corrosion
• 1-year limited warranty
• ASSE® Listed 1020
• CSA® Certified B64.1.2
• Approved by the Foundation for Cross Connection Control and Hydraulic Research at the University of Southern California

Common Questions

What hazard level is this PVB approved for?

It is rated for high health hazard (toxic) cross-connections, but only against backsiphonage. The assembly is listed to ASSE 1020.

Is this model legal for potable water?

Yes. It is certified lead-free to NSF/ANSI 372, which is what state plumbing codes require for any device in a drinking-water line.

Does this assembly have to be tested every year?

Yes. This is a field-testable assembly. Most water authorities require it to be tested and certified by a licensed backflow tester at installation and annually thereafter. It carries USC FCCCHR approval, which many jurisdictions accept as their sole approval list.

Will this protect against backpressure?

No. A pressure vacuum breaker protects against backsiphonage only. It will not stop backflow caused by backpressure -- a downstream pump, elevated piping or a boiler -- which requires a double check or RPZ assembly instead.

How does this have to be installed?

It must be installed vertically (upright), above the highest downstream outlet, per its installation instructions and ASSE listing.

Specifications

• Type: Pressure Vacuum Breaker Assembly with Integral Anti-Freeze Relief Valve
• Size: 1"
• Connection: FNPT
• Body Material: Stainless
• Max Pressure (psi): 175
• Application: Irrigation
• Backflow Protection: Backsiphonage
• MPN: 1-420XL
• Temperature: up to 140°F
• Certifications: ASSE-1020, CSA-B64.1.2, USC, NSF-372, IAPMO
• Lead-Free: Yes
• Assembly Type: PVB
• Hazard Protection Level: High Health Hazard
• ASSE Standard: ASSE 1020
• USC FCCCHR Approved: Yes
• Field Testable: Yes
• Approved Orientation: Vertical