4 inch x 3 inch PVC Sewer and Drian Reducing Coupling Hub x Hub

4 inch x 3 inch PVC Sewer & Drain Reducing Coupling – Transition Fitting for Gravity-Flow Systems

The 4 inch x 3 inch PVC Sewer and Drain Reducing Coupling provides a direct solvent-weld transition between 4-inch and 3-inch non-pressure drain pipes. Commonly used in gravity-flow sanitary and storm drainage systems, this fitting supports changes in pipe diameter while maintaining flow efficiency and structural continuity in PVC piping assemblies.

Molded from durable PVC material and manufactured to ASTM D3034 or F679 standards, this coupling offers dimensional consistency and chemical resistance. Socket end connections accept standard SDR-35 PVC piping for solvent-welded joints used in underground or above-grade installations.

Product Features

• ✅ Injection-Molded PVC: Resistant to soil chemicals, corrosion, and impact damage under buried or exposed conditions.
• ✅ Solvent Weld Connections: Provides a permanent joint when used with approved primer and cement; eliminates the need for mechanical clamps or gaskets.
• ✅ Concentric Transition: Designed for direct axial alignment between 4 inch and 3 inch pipes in drainage lines.
• ✅ Non-Pressure Rated: Suitable for DWV and storm sewer applications only; not intended for potable water or pressurized systems.
• ✅ Compliance: Meets applicable requirements under ASTM D2729 or D3034 for sewer and drain components.

Installation Guidelines

Ensure both pipe ends are chamfered, clean, and dry before applying primer and cement. Insert fully into the coupling socket and rotate slightly to ensure full solvent contact. Follow cure time guidelines per solvent manufacturer instructions before pressurizing downstream systems. Install with proper grade and support per IPC or local code requirements.

Typical Use Cases

This reducing coupling is utilized in gravity drainage systems to transition from 4-inch mains to 3-inch lateral branches or fixture arms. Common in site utility installations, cleanout connections, and drainage retrofits in commercial, municipal, and residential systems.

Material Note

PVC fittings offer long-term resistance to corrosion and root intrusion when properly installed and backfilled. They are approved for underground use in sanitary sewer systems where pressure performance is not required.

Specification Summary

• Nominal Sizes: 4 inch x 3 inch
• Material: PVC (Polyvinyl Chloride)
• Connection Type: Slip x Slip (Solvent Weld)
• Applicable Standards: ASTM D3034, ASTM D1784 (cell classification 12454)
• Application: Non-pressurized sewer and drain lines

The 4 inch x 3 inch PVC Sewer and Drain Reducing Coupling offers an efficient transition between pipe sizes while maintaining structural reliability in DWV systems. With proper solvent welding and adherence to code-based installation practices, this fitting supports long-lasting drainage performance in engineered gravity piping networks.