Moore Supply Co ML-SF446P 4 Inch Pvc Backwater Valve

Product Description

The MOORE SUPPLY CO ML-SF446P is a 4-inch PVC backwater valve designed to prevent sewage backflow from entering a building through the drain system. Installed in the main drain line, it uses a one-way check mechanism that allows wastewater to flow out while blocking reverse flow caused by sewer surcharges or flooding events. At 4.75 pounds, this valve is suited for residential and light commercial drain systems where code-compliant backflow protection is required. Licensed plumbers install this fitting as part of a properly sloped and accessible drain assembly.

This backwater valve is used in 4-inch gravity drain applications, typically on main building drains, floor drains, or branch lines subject to sewer backup risk. It is appropriate for below-grade installations in residential basements and crawl spaces, as well as light commercial utility rooms where the drain line is at or below the municipal sewer elevation. The PVC construction makes it compatible with standard PVC drain, waste, and vent piping.

Key Features

• 4-inch PVC construction for compatibility with standard DWV piping
• One-way check mechanism prevents sewage backflow into the building
• Lightweight at 4.75 pounds for easier handling during installation
• Suited for below-grade drain protection in residential and light commercial settings
• PVC body resists corrosion and chemical degradation common in drain environments

Compatibility

Designed as an OEM-style replacement and new-installation fitting for 4-inch PVC drain, waste, and vent systems in residential and light commercial applications.

Installation Notes

Installation should be performed by a licensed plumber in accordance with local plumbing codes and the International Plumbing Code (IPC). Shut off water service and ensure the drain line is clear and depressurized before cutting into the existing pipe. The valve must be installed in the correct flow direction as indicated on the body, and the assembly should remain accessible for periodic inspection and cleaning per code requirements. Do not install in pressurized lines or applications outside the rated pipe size.

Technical Specifications

• Pipe Size: 4 inches
• Material: PVC
• Weight: 4.75 pounds
• UPC Code: 717510044003

Standard Information

• Brand: MOORE SUPPLY CO
• Manufacturer Part Number: ML-SF446P