Zurn Wilkins RK1-350BOF 1-Inch Blow-Out Flush Fitting and O-Rings Repair Kit User Manual

1. Introduction

This manual provides detailed instructions for the proper installation, operation, and maintenance of the Zurn Wilkins RK1-350BOF Blow-Out Flush Fitting and O-Rings Repair Kit. This kit is specifically designed for winterizing 1-inch Wilkins 350 series double check assemblies, facilitating the removal of water from the device and associated lines to prevent freeze damage. Adhering to these instructions will ensure optimal performance and longevity of your plumbing system.

2. Product Overview

The Zurn Wilkins RK1-350BOF is a specialized fitting used for the winterization of 1-inch Wilkins 350 series double check backflow preventers. It replaces the internal cartridge housing during the winter months, allowing for easy connection of an air compressor to blow out water from the irrigation lines. The fitting includes two 3/4-inch NPT female taps for air connection and comes with replacement O-rings.

Figure 1: An orange plastic Zurn Wilkins RK1-350BOF blow-out flush fitting, designed for winterization, shown with two black O-rings. The fitting features threaded ports for air connection and mounting holes.

3. Safety Information

• Always shut off the main water supply before beginning any work on the backflow preventer or irrigation system.
• Wear appropriate personal protective equipment, including safety glasses, when working with tools and pressurized air.
• Ensure all connections are secure before applying air pressure.
• Do not exceed the recommended air pressure for your irrigation system components. Consult your irrigation system manual for pressure limits.
• Keep children and pets away from the work area.

4. Setup and Installation

The RK1-350BOF fitting is designed for straightforward installation without special tools. Follow these steps to install the blow-out fitting for winterization:

1. Prepare the System: Shut off the main water supply to the irrigation system. Open both the inlet and outlet shutoff valves on the Wilkins 350 series double check assembly. Open all four test cocks using a flat-head screwdriver to relieve any residual pressure.
2. Remove Valve Assembly: Locate the four bolts securing the existing valve assembly (cartridge housing) within the backflow preventer. Using a 3/8-inch wrench or socket, carefully unscrew these four bolts. Gently pry out the valve assembly with a screwdriver, taking care not to damage any internal components or the main body of the backflow preventer.
3. Install Blow-Out Fitting: Insert the Zurn Wilkins RK1-350BOF blow-out fitting into the cavity where the valve assembly was removed. Ensure the fitting is properly seated.
4. Secure the Fitting: Reinsert and tighten the four bolts to secure the RK1-350BOF fitting in place. Do not overtighten.
5. Connect Air Compressor: Attach your air compressor hose to one of the 3/4-inch FNPT (Female National Pipe Taper) ports on the blow-out fitting. You may need to purchase appropriate bushings and air fitting adapters from a hardware or automotive store to match your compressor hose.
6. Position Valves for Winter: For optimal winter protection, leave the blow-out fitting in place for the duration of the cold season. Position both the inlet and outlet shutoff valves in a half-open, half-closed position. Close all four test cocks. Consider plugging the 3/4-inch FNPT ports on the blow-out fitting to prevent debris or critters from entering the system.

5. Operating Instructions (Winterization)

Once the RK1-350BOF fitting is installed and the air compressor is connected, proceed with the winterization process:

1. Isolate Zones: Ensure all irrigation zone valves are closed.
2. Apply Air Pressure: Slowly open the air compressor valve to introduce air into the system. Begin with the zone furthest from the backflow preventer.
3. Blow Out Zones: Open one irrigation zone valve at a time. Allow air to flow through the zone until water is no longer expelled from the sprinkler heads, indicating the line is clear. Close the zone valve.
4. Repeat for All Zones: Repeat the process for each irrigation zone until all lines are thoroughly cleared of water.
5. Disconnect: Once all zones are blown out, close the air compressor valve and disconnect the hose from the blow-out fitting.

6. Maintenance

• O-Ring Lubrication: The kit includes O-rings. Before installation, apply a small amount of silicone-based grease (often included with the kit) to the O-rings to ensure a proper seal and prevent premature wear.
• Inspection: Annually inspect the blow-out fitting and O-rings for any signs of wear, cracks, or damage. Replace components as necessary.
• Storage: When not in use, store the RK1-350BOF fitting in a clean, dry place away from direct sunlight and extreme temperatures.

7. Troubleshooting

• Air Leakage: If air leaks are detected around the fitting, ensure the four securing bolts are tightened correctly and the O-rings are properly seated and lubricated. Inspect O-rings for damage and replace if necessary.
• Difficulty Seating: If the fitting does not seat correctly, ensure the cavity is free of debris and the O-rings are not pinched. Verify that you have the correct model (RK1-350BOF) for your 1-inch Wilkins 350 series assembly.
• No Air Flow: Check that the main water supply is completely off, all test cocks are closed, and the air compressor is functioning correctly and connected securely. Ensure all irrigation zone valves are closed before opening them one by one.

8. Specifications

9. Warranty and Support

For information regarding product warranty or technical support, please contact Zurn customer service directly. Refer to the official Zurn website or product packaging for the most current contact details and warranty terms.

Zurn Website: www.zurn.com