Watts LFN45BM1-U Water Pressure Reducing Valve Instruction Manual

Introduction

This manual provides comprehensive instructions for the Watts LFN45BM1-U Standard Capacity Water Pressure Reducing Valve. This 3/4 inch valve is designed to reduce incoming water pressure, thereby protecting plumbing systems and optimizing water consumption in commercial, industrial, and residential settings. Proper installation, operation, and maintenance are crucial for the valve's longevity and effective performance.

Figure 1: Front view of the Watts LFN45BM1-U Water Pressure Reducing Valve.

Key Features

• Reduces incoming water pressure to protect plumbing systems and reduce water consumption.
• Suitable for up to 400 psi (27.6 bar) maximum operating pressure.
• Adjustable pressure range from 25 to 75 psi (172 to 517 kPa), with a standard factory setting of 50 psi (345 kPa).
• Constructed with a lead-free brass body for durability and safety.
• Features NPT Union inlet and NPT Female outlet connections.
• Includes an integral stainless-steel strainer, which is removable for cleaning.
• Equipped with a thermoplastic seat module.
• Incorporates a thermal expansion bypass feature to control pressure increases on the outlet side due to thermal expansion.
• Designed with a sealed spring cage, suitable for waterworks pit installations.
• Offers easy installation, handling, and in-line serviceability.
• Temperature range: 33 to 180 degrees F (0.5 to 82 degrees C).

Safety Information

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Always ensure that installation and maintenance are performed by qualified personnel in accordance with local plumbing codes and regulations.

Installation

Pre-Installation Checks

• Verify that the incoming water pressure does not exceed 400 psi (27.6 bar).
• Ensure the water temperature is within the range of 33 to 180 degrees F (0.5 to 82 degrees C).
• Confirm that the valve size (3/4 inch) and connection types (NPT Union inlet, NPT Female outlet) match your plumbing system.
• Gather all necessary tools and additional plumbing components.

Installation Steps

1. Shut off the main water supply to the property.
2. Drain the water lines to relieve pressure.
3. Identify the appropriate location for the pressure reducing valve, typically after the main shut-off valve and before any branch lines.
4. Apply appropriate thread sealant (e.g., PTFE tape or pipe dope) to the NPT threads.
5. Connect the NPT Union inlet of the valve to the incoming water line.
6. Connect the NPT Female outlet of the valve to the downstream plumbing system.
7. Ensure all connections are tight and leak-free.
8. Slowly restore the main water supply and check for leaks.
9. Adjust the pressure as described in the Operation section.

Figure 2: Example installation of a pressure reducing valve, often with a pressure gauge for monitoring.

Operation

The Watts LFN45BM1-U valve is designed to automatically reduce and maintain a constant downstream water pressure, regardless of fluctuations in the upstream (incoming) pressure. The factory preset pressure is typically 50 psi (345 kPa), but it can be adjusted within a range of 25 to 75 psi (172 to 517 kPa).

Pressure Adjustment

1. To increase the downstream pressure, turn the adjustment screw (located on top of the valve) clockwise.
2. To decrease the downstream pressure, turn the adjustment screw counter-clockwise.
3. Use a pressure gauge installed downstream of the valve to accurately monitor the adjusted pressure.
4. After adjustment, open a downstream faucet to allow water to flow, then close it to verify the new static pressure reading. Repeat adjustment if necessary.

Maintenance

Regular maintenance ensures the optimal performance and longevity of your Watts LFN45BM1-U valve. The primary maintenance task involves cleaning the integral stainless-steel strainer.

Cleaning the Integral Strainer

1. Shut off the main water supply to the valve.
2. Relieve any pressure in the downstream plumbing system by opening a faucet.
3. Carefully remove the cap or plug that secures the integral strainer. Refer to the product diagram for exact location.
4. Extract the stainless-steel strainer.
5. Rinse the strainer thoroughly under running water to remove any accumulated debris. Use a soft brush if necessary.
6. Inspect the strainer for any damage or wear. Replace if necessary.
7. Reinsert the clean strainer and secure the cap or plug.
8. Slowly restore the water supply and check for leaks.

Figure 3: Typical components of a pressure reducing valve kit, showing a strainer and sealing washers.

Troubleshooting

If you experience issues with your Watts LFN45BM1-U Water Pressure Reducing Valve, consider the following common troubleshooting steps:

• Low or Fluctuating Downstream Pressure: Check the integral strainer for clogs and clean if necessary. Ensure the adjustment screw is set correctly. Verify upstream pressure is adequate.
• High Downstream Pressure (Pressure Creep): This can occur due to thermal expansion in a closed plumbing system. Ensure a properly sized and functioning thermal expansion tank is installed. The valve's bypass feature helps manage this, but an expansion tank is often required by code.
• Leaks: Inspect all connections for proper sealing. Ensure thread sealant was applied correctly. Check for any visible damage to the valve body or internal components.
• No Water Flow: Confirm the main water supply is on and the valve is not completely closed. Check for severe clogs in the strainer or piping.

For persistent issues or complex problems, it is recommended to consult a qualified plumber.

Specifications

Warranty and Support

For specific warranty information, please refer to the documentation included with your purchase or visit the official Watts website. For technical support, replacement parts, or further assistance, please contact Watts customer service directly. Ensure you have your product model number (LFN45BM1-U) available when contacting support.