Zurn 4-375DA Lead-Free Backflow Preventer - Reduced Pressure Principle Detector Assembly

The Zurn Wilkins 4-375DA 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 375DA Reduced Pressure Principle Detector Backflow Assembly protects against backsiphonage and backpressure of contaminated water in high hazard, fire protection applications. The 375DA features a metered bypass to effectively detect leaks and any unauthorized water use. Materials include an epoxy-coated ductile iron body, and stainless steel internals, fasteners, springs, and sensing line. The Wilkins Compound Check provides low headloss and superior performance and valves short lay-lenght makes the 375DA ideal for any backflow replacement.

Features

• Relief valve and checks are easily accessible for in-line maintenance
• Leak and unauthorized water use detection decreases costs over time
• Protection from contaminated water in high hazard fire protection applications
• Epoxy-coated ductile iron body and stainless steel internals resist corrosion
• Lowest lifecycle costs
• UL® Classified
• AWWA Compliant

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 - Reduced Pressure Principle Detector Assembly
• Size: 4"
• Connection: Flanged
• Body Material: Ductile Iron
• Max Pressure (psi): 175
• Application: Fire Protection
• Backflow Protection: Both
• MPN: 4-375DA
• Temperature: up to 140°F
• Certifications: ASSE-1047, AWWA-C550, AWWA-C606, CSA-B64.4, 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