Zurn Wilkins 375ST Stainless Steel RPZ Reduced Pressure Backflow Preventer

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

Product Overview

The Zurn Wilkins 375ST Series Reduced Pressure Principle Assembly (RPZ) Backflow Preventers deliver exceptional protection for potable water systems while offering superior corrosion resistance. Built with stainless steel components and reinforced nylon housing, the 375ST is designed for environments where bronze valves are not suitable, such as food service facilities, breweries, distilleries, laboratories, and medical applications.

Available in ½", ¾", and 1" sizes, the 375ST series provides reliable protection against both backsiphonage and backpressure, keeping potable water supplies safe from contamination. Lightweight, compact, and fully lead-free, these assemblies are easy to install and maintain. With repair kits available, the 375ST is also a cost-effective solution for long-term backflow prevention.

Features & Benefits

• All-Stainless Steel & Engineered Plastics – Provides unmatched resistance to corrosion.

• Lead-Free Certified – Meets NSF/ANSI/CAN 61 and NSF/ANSI 372 standards.

• Compact & Lightweight – Easy to install in confined mechanical rooms or retrofit projects.

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

• Cost-Effective Maintenance – Repair kits extend service life, reducing replacement costs.

• Versatile Applications – Ideal for industries with corrosive water systems: food and beverage, healthcare, and processing facilities.

• Certified & Approved – ASSE® 1013, CSA® B64.4, USC Foundation approval, IAPMO R&T certified.

Specifications

• Available Sizes: ½", ¾", 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

• End Connections: Threaded FNPT ANSI B1.20.1

Dimensions & Weights (Approx.)

• ½" & ¾" Models: 8 7/8" length, ~4.7 lbs (without valves), ~5.7 lbs (with valves)

• 1" Model: 11 3/16" length, ~8.2 lbs (without valves), ~9.7 lbs (with valves)

Installation Tips

• Install between 12" (305mm) and 30" (762mm) above an adequate drain with proper clearance for testing.

• Ensure no part of the assembly is submerged during operation.

• For indoor installations, use an air gap adapter for compliance.

• Follow manufacturer instructions and Uniform Plumbing Code requirements.

• Verify flow direction using the body markings before installation.

FAQs

Q: What applications are best for the 375ST Series?
A: The 375ST is ideal for potable water systems in food service, breweries, distilleries, healthcare facilities, and any installation requiring corrosion-resistant materials.

Q: Do these models meet lead-free standards?
A: Yes, all 375ST models comply with NSF/ANSI/CAN 61 and NSF/ANSI 372 with less than 0.25% lead content.

Q: Can repair kits be purchased for these models?
A: Yes, genuine Zurn Wilkins repair kits are available, providing a cost-effective alternative to full replacement.

Q: Do all sizes provide the same level of backflow protection?
A: Yes, whether ½", ¾", or 1", each model provides reduced pressure principle protection against backsiphonage and backpressure.