Zurn 4-475DA Lead-Free Backflow Preventer - N-Pattern Reduced Pressure Principle Detector Assembly

The Zurn Wilkins 4-475DA is a 4" lead-free reduced pressure detector assembly (RPDA) 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 475DA/475DAV Reduced Pressure Detector Backflow Assembly is utilized in high hazard, fire protection applications to protect against both backsiphonage and backpressure. The 475DA is shaped in the n-Pattern for new or retrofit installations in compact spaces, while the 475DAV is shaped in the z-Pattern and installed vertically in a flow up orientation. Both models include a small footprint for quick and easy fire protection retrofit applications, as well as a metered bypass system to detect leaks and any unauthorized water use, saving you valuable time and money on repairs and maintenance costs.

Features

• Small footprint for easy Fire Protection retrofits
• 475DA assembled in "N" pattern
• 475DAV allows for vertical up flow in a "Z" pattern

Common Questions

What hazard level is this RPDA 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 1047.

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.

What shutoff valves are included?

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

Is this suitable for a fire sprinkler line?

Yes. Detector assemblies are built for fire sprinkler service: the metered bypass registers the low flows that reveal a leak or an unauthorized tap on the fire line. This model is UL Classified and C-UL Classified and FM Approved. The bypass meter reads in GPM.

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: Backflow Preventer - N-Pattern Reduced Pressure Principle Detector Assembly
• Size: 4"
• Connection: Flanged
• Body Material: Ductile Iron
• Max Pressure (psi): 175
• Application: Fire Protection
• Backflow Protection: Both
• MPN: 4-475DA
• Temperature: up to 140°F
• Certifications: ASSE-1047, AWWA-C550, AWWA-C606, C-UL, UL, FM, USC, NSF-61, NSF-372
• Lead-Free: Yes
• Assembly Type: RPDA
• Hazard Protection Level: High Health Hazard
• ASSE Standard: ASSE 1047
• USC FCCCHR Approved: Yes
• Fire Protection Listing: UL Classified;C-UL Classified;FM Approved
• Field Testable: Yes
• Shutoff Valves: NRS Gate
• Bypass Meter: GPM