Zurn Wilkins 1-375ST 1" Stainless Steel RPZ Reduced Pressure Backflow Preventer

Zurn Wilkins 1-375ST 1" Stainless Steel RPZ Reduced Pressure Principle Backflow Preventer – Lead-Free.

Product Overview

The Zurn Wilkins 1-375ST Reduced Pressure Principle Assembly (RPZ) is a premium backflow preventer designed for applications where maximum protection and corrosion resistance are essential. Built with stainless steel components and reinforced nylon housing, the 375ST ensures durability in demanding environments such as food processing facilities, breweries, distilleries, laboratories, and medical equipment systems.

This lead-free backflow preventer provides reliable protection against both backsiphonage and backpressure, safeguarding potable water supplies from contamination. Compact, lightweight, and easy to maintain, the 375ST is an excellent choice for systems where bronze valves are not suitable due to corrosion.

Features & Benefits

• All Stainless Steel & Engineered Plastics – Provides superior corrosion resistance compared to bronze valves.

• Lead-Free Certified – Meets NSF/ANSI/CAN 61 & 372 requirements for potable water applications.

• Compact & Lightweight – Easier handling and installation in confined spaces.

• Durable Construction – Reinforced nylon housing, stainless steel fasteners and springs, and FDA-approved elastomers.

• Cost-Saving Maintenance – Repair kits available for long-term service life without full replacement.

• Wide Application Use – Excellent for corrosive water systems, food service, medical, and industrial settings.

• Certified & Approved – ASSE® 1013, CSA® B64.4, USC Foundation approved, NSF® listed.

Specifications

• Model: 1-375ST

• Size: 1" (available in 1/2", 3/4", and 1")

• Maximum Working Pressure: 175 PSI

• Hydrostatic Test Pressure: 350 PSI

• Maximum Temperature: 180°F (82°C)

• Housing: Reinforced Nylon (FDA approved)

• Elastomers: Silicone & Buna N (FDA approved)

• Internals: Delrin, Nylon

• Springs & Struts: Stainless Steel, 300 Series

• Ball Valves: Cast Stainless Steel ASTM A351, CF-8M

• Connections: Threaded FNPT, ANSI B1.20.1

Installation Tips

• Must be installed in accordance with local plumbing codes and Uniform Plumbing Code.

• Mount 12" (305mm) to 30" (762mm) above an adequate drain with proper side clearance for servicing.

• Ensure no part of the unit is submerged.

• For indoor installations, use an air gap adapter (Model AG) to meet compliance.

• Install with the flow direction arrow aligned to piping layout.

FAQs

Q: What makes the 375ST different from standard bronze backflow preventers?
A: The 375ST uses stainless steel and reinforced nylon, making it corrosion-resistant and ideal for food service, medical, and industrial applications.

Q: Does this unit meet lead-free requirements?
A: Yes, it meets NSF/ANSI/CAN 61 & 372 standards, with less than 0.25% weighted average lead content.

Q: Can this be installed indoors?
A: Yes, but it must be paired with an air gap adapter and drain per code.

Q: What industries commonly use the 375ST?
A: Food and beverage production, breweries, distilleries, labs, and medical facilities where corrosion resistance is critical.