Zurn Wilkins RK4-375CK1 Backflow Preventer #1 Check Assembly Repair Kit (375 / 475)

Zurn Wilkins RK4-375CK1 Backflow Preventer #1 Check Assembly Repair Kit

Product Overview

The Zurn Wilkins RK4-375CK1 #1 Check Assembly Repair Kit is a genuine OEM replacement kit designed to restore the performance and reliability of your Zurn Wilkins backflow preventers. This kit services the #1 check assembly, ensuring that your Reduced Pressure Principle Assembly (RPZ) continues to protect potable water systems against backflow hazards.

Engineered for long-lasting durability, the RK4-375CK1 includes all necessary components—check assembly, retainer clip, and lubricant—for quick and efficient maintenance. It is compatible with a wide range of 375, 375A, 375ADA, 375DA, 475, and 475DA series backflow preventers, making it a versatile and cost-effective solution for professional plumbers, contractors, and facility managers.

Features & Benefits

• OEM Replacement Kit – Designed for Zurn Wilkins RPZ backflow preventers.

• Complete Service Kit – Includes #1 check assembly, retainer clip, and lubricant.

• Restores Performance – Maintains proper sealing and functionality of the primary check assembly.

• Durable Materials – Built to withstand corrosion and wear in demanding applications.

• Wide Model Compatibility – Fits several Zurn Wilkins 375 and 475 series assemblies.

• Cost-Effective Maintenance – Extends the life of your backflow preventer without full replacement.

Specifications

• Kit Model: RK4-375CK1

• Application: #1 check assembly replacement

• Includes: Check assembly, retainer clip, lubricant

• Fits Zurn Wilkins Models:

  • 2-1/2" & 3" Valves: 212-375A, 212-375ADA, 3-375A, 3-375ADA

  • 4" Valves: 4-375, 4-375OSY, 4-375DA, 4-375DAOSY, 4-475, 4-475OSY, 4-475DA, 4-475DAOSY

Installation Tips

• Shut off water supply and depressurize the assembly before servicing.

• Remove existing #1 check assembly and install the new replacement components.

• Apply the included lubricant to ensure smooth installation and proper sealing.

• Reassemble and test the backflow preventer to verify compliance with local codes.

• Professional installation is recommended for proper certification.

FAQs

Q: What does this repair kit include?
A: The kit includes a replacement #1 check assembly, retainer clip, and lubricant.

Q: Which Zurn Wilkins models are compatible?
A: It fits 375A, 375ADA, 375, 375DA, 475, and 475DA Reduced Pressure Principle Assemblies.

Q: Why replace the #1 check assembly?
A: The #1 check valve is the primary protection against backflow. Replacing worn parts restores full functionality and ensures system safety.

Q: Can this kit be installed without specialized tools?
A: Basic tools are sufficient, but testing after repair must be done by a certified professional to meet code.