Fernco 44u-317 Donut Service Coupling 4x3 Inch Ci Hub Copper

Product Description

The FERNCO 44u-317 is a donut-style service coupling designed to connect a 4-inch cast iron hub to a 3-inch copper pipe. This flexible transition fitting is used in drain, waste, and vent (DWV) systems where dissimilar pipe materials must be joined at a hub connection. The fitting uses a compression-style elastomeric sleeve that creates a leak-resistant seal without soldering, threading, or special tooling. Weighing 1.5 pounds and sized at 4 inches by 3 inches, it is compact enough for tight access locations common in retrofit and repair work. Licensed plumbers and experienced service techs are the primary installers.

This coupling is suited for residential and light commercial plumbing repair and replacement work. It is typically used when connecting copper drain pipe to an existing cast iron hub, a common scenario during fixture replacement, bathroom renovations, or partial drain line repairs. The donut configuration seats into the cast iron hub while gripping the copper stub-out, making it a practical solution for service calls where cutting in a full coupling is not feasible.

Key Features

• Transitions a 4-inch cast iron hub to a 3-inch copper pipe in a single fitting
• Donut-style design seats directly into the cast iron hub for a secure connection
• Flexible elastomeric construction accommodates minor misalignment and pipe movement
• No soldering, threading, or hot work required for installation
• Compact form factor suitable for confined access areas

Compatibility

Designed as an OEM-style replacement and service fitting for 4-inch cast iron hub to 3-inch copper DWV pipe transitions in residential and commercial drain, waste, and vent systems.

Installation Notes

Installation is performed by a licensed plumber. Shut off the water supply and ensure the drain system is empty before beginning work. Clean the cast iron hub interior and the copper pipe exterior thoroughly to remove debris, scale, or old sealant prior to seating the fitting. Follow local plumbing code requirements, including applicable IPC provisions, for DWV transition fittings.

Technical Specifications

• Fitting Size: 4 inches x 3 inches
• Item Weight: 1.5 pounds
• Connection Type: Cast Iron Hub x Copper
• Style: Donut Service Coupling

Standard Information

• Brand: FERNCO
• Manufacturer Part Number: 44u-317