Zurn 6-350AST Lead-Free Backflow Preventer - Stainless Steel Double Check Valve Assembly

The Zurn Wilkins 6-350AST is a 6" lead-free double check valve assembly with Flanged connections, approved for low 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 350AST Double Check Backflow Assembly protects against backsiphonage and backpressure in low health hazard applications. The use of our Patented Compound Check guarantees reliable performance and improved flow characteristics, making installation ideal for lower-pressure systems. Its 304L grade stainless steel valve body and access covers are corrosion-resistant for lower lifetime maintenance costs. Its lightweight design and short lay-length also ensures easy, compact installation. Choose from multiple shut-off and end connection options such as flanged, grooved, or grooved x flanged for ultimate versatility.

Features

• Stainless steel body and access covers offer corrosion-resistance
• Lightweight design and short lay-length ensures easy, compact installation
• Ideal for any Backflow Preventer replacement
• Model 350ASTR available for custom length, drop-in replacements
• Multiple gate valve and end connection options provides installation versatility
• ASSE® Listed and AWWA Compliant
• UL® Classified and C-UL® Classified

Common Questions

What hazard level is this Double Check approved for?

It is rated for low health hazard (non-toxic, "pollutant") cross-connections only. Where the downstream substance could be a health hazard, codes require a reduced pressure zone (RPZ) assembly or a detector assembly instead. The assembly is listed to ASSE 1015.

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 with 4 test cocks. 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.

What shutoff valves are included?

It is supplied with non-rising stem (NRS) resilient-seated gate valves on the inlet and outlet.

Is this listed for fire protection service?

Yes -- it is UL Classified and C-UL Classified and FM Approved, the listings normally required for a backflow device on a fire sprinkler supply.

How does this have to be installed?

It is approved for either horizontal or vertical installation, with the flow arrow on the body pointing in the direction of flow.

Specifications

• Type: Backflow Preventer - Stainless Steel Double Check Valve Assembly
• Size: 6"
• Connection: Flanged
• Body Material: Stainless
• Max Pressure (psi): 175
• Application: Domestic Water
• Backflow Protection: Both
• MPN: 6-350AST
• Temperature: up to 140°F
• Certifications: ASSE-1015, AWWA-C510, AWWA-C606, CSA-B64.5, C-UL, UL, FM, USC, NSF-61, NSF-372, IAPMO
• Lead-Free: Yes
• Assembly Type: Double Check
• Hazard Protection Level: Low Health Hazard
• ASSE Standard: ASSE 1015
• USC FCCCHR Approved: Yes
• Fire Protection Listing: UL Classified;C-UL Classified;FM Approved
• Field Testable: Yes
• Number of Test Cocks: 4
• Shutoff Valves: NRS Gate
• Approved Orientation: Horizontal & Vertical