Zurn 4-475 Lead-Free Reduced Pressure Principle Backflow Preventer, Ductile Iron, Flanged

The Zurn Wilkins 4-475 is a 4" lead-free reduced pressure zone (RPZ) backflow preventer with Flanged connections, approved for high health hazard protection. It features a ductile iron body. Rated to 175 psi and up to 140°F. This model is certified lead-free for potable-water installations.

The 475/475V Reduced Pressure Principle Backflow Preventers are utilized in high hazard, potable water applications to protect against both backsiphonage and backpressure. The Model 475 is shaped in the n-Pattern, and is used in vertical flow up and vertical flow down applications, often for new or retrofit installations in compact spaces. Its single access cover reduces maintenance downtime and repair costs. Alternatively, the Model 475V is shaped in the z-Pattern and is installed in vertical flow up applications. Both models are equipped with the patented, center-stem guided Compound Check for low headloss, superior reliability, and unmatched performance.

Features

• Available as a 475V for RP protection in a vertical upward flow path
• "n" pattern construction space saving design is excellent for retrofit installation in small spaces
• Epoxy coated ductile iron body resists corrosion
• Utilizes the patented, center-stem guided Compound Check for reliable and superior performance
• Single access cover reduces maintenance down time

Common Questions

What hazard level is this RPZ approved for?

It is rated for high health hazard (toxic) cross-connections, so it may be used on either high or low hazard service. The assembly is listed to ASSE 1013.

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

Does the relief valve need a drain?

Yes. An RPZ relief valve is designed to discharge, and it can dump a large volume of water, so it must never be installed in a pit or below grade and the discharge must be piped to an adequate drain through an air gap. The air gap fitting is not included with this model and is ordered separately.

Specifications

• Type: Reduced Pressure Principle Backflow Preventer
• Size: 4"
• Connection: Flanged
• Body Material: Ductile Iron
• Max Pressure (psi): 175
• Application: Domestic Water
• Backflow Protection: Both
• MPN: 4-475
• Temperature: up to 140°F
• Certifications: ASSE-1013, AWWA-C511, AWWA-C606, CSA-B64.4, C-UL, UL, FM, USC, NSF-61, NSF-372, IAPMO
• Lead-Free: Yes
• Assembly Type: RPZ
• Hazard Protection Level: High Health Hazard
• ASSE Standard: ASSE 1013
• 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: Vertical