Mueller Streamline CORED43 Copper Reducing Coupling

Product Description

The MUELLER STREAMLINE CORED43 is a copper reducing coupling designed to connect a 4-inch pipe to a 3-inch pipe using a sweat (C x C) end configuration. This fitting is used in plumbing and mechanical piping systems where a transition between two different nominal pipe diameters is required. The C x C connection type means both ends accept copper tubing that is soldered in place, creating a permanent, pressure-rated joint. Licensed plumbers and pipefitters install this type of fitting in new construction and retrofit applications across residential and light commercial systems.

This reducing coupling is suited for installations where a 4-inch copper run must step down to a 3-inch copper run, such as main supply lines, drain headers, or mechanical room piping. The sweat-solder end connections are standard practice in copper piping systems for water distribution, hydronic heating, and related fluid-handling applications. Both ends are sized to accept standard nominal copper tubing per common industry dimensions.

Key Features

• Reduces from 4-inch to 3-inch nominal copper pipe in a single fitting
• C x C (sweat) end connections on both sides for soldered permanent joints
• Copper construction provides corrosion resistance in water and hydronic fluid service
• Straight inline reducing coupling design for compact installation

Compatibility

Designed as an OEM-style replacement and standard-use fitting compatible with 4-inch and 3-inch nominal copper tubing systems following sweat-solder connection practices.

Installation Notes

Installation should be performed by a licensed plumber in accordance with applicable local plumbing codes and IPC standards. Shut off and drain the water supply completely before cutting into any existing piping. Clean and flux both the tube ends and fitting sockets thoroughly before applying heat to ensure a sound soldered joint. Do not apply flame directly to the fitting for extended periods, as overheating can damage the copper or result in a failed joint.

Technical Specifications

• Inlet Size: 4 inches
• Outlet Size: 3 inches
• Connection Type: C x C (Sweat Solder)
• Material: Copper

Standard Information

• Brand: MUELLER STREAMLINE
• Manufacturer Part Number: CORED43