Product Description
The NDS 475PR is a 4-inch IPS PVC backwater valve with an integrated 16-inch riser, designed to prevent sewage backflow in residential and light commercial drainage systems. The valve allows wastewater to flow in one direction while automatically blocking reverse flow caused by sewer surcharges or flooding events. Constructed in PVC, it offers corrosion resistance suitable for underground drainage applications. The extended riser provides accessible cleanout depth without excavation, making it practical for standard below-grade installations. Licensed plumbers and drainage contractors are the primary installers of this fitting.
This backwater valve is used in gravity-flow sanitary drain lines where sewer backflow protection is required by local plumbing codes. Typical installations include basement floor drain lines, building drain mains, and other below-slab or below-grade drain configurations that connect to municipal sewer systems. The 4-inch IPS connection size accommodates the most common residential and light commercial main drain line diameter. The 16-inch riser height provides service access at grade or near-grade level once the valve is buried at the required depth.
Key Features
- 4-inch IPS connection size fits standard residential and light commercial main drain lines
- PVC construction provides corrosion resistance in underground drainage environments
- Integrated 16-inch riser allows above-grade or near-grade access for inspection and cleaning
- Automatic backflow prevention blocks reverse sewer flow without manual intervention
- One-directional flow design protects occupied spaces from sewage backflow during surcharge events
Compatibility
Designed as an OEM-style replacement and new-installation fitting for 4-inch IPS PVC sanitary drain 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). The drain line must be fully de-pressurized and isolated before cutting into an existing line to install this valve. Confirm correct flow-direction orientation before solvent-welding connections, as reversing the valve will block normal drainage. Backfill around the valve body carefully to avoid distorting the PVC housing during compaction.
Technical Specifications
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Connection Size: 4 inches IPS
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Riser Height: 16 inches
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Material: PVC
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Weight: 4.45 pounds
Standard Information
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Brand: NDS
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Manufacturer Part Number: 475PR
