Ay Mcdonald 4423-376 Pex-a Poly Insert Coupling

Product Description

The AY MCDONALD 4423-376 is a reducing poly insert coupling designed to join PEX-A tubing in plumbing and hydronic piping systems. It transitions from 3/4 inches to 1/2 inches, making it a practical fitting for branch runs, fixture supply lines, and other applications where tube diameter steps down. The insert-style design is compatible with PEX-A expansion installation methods, and the polyethylene construction resists corrosion and scale buildup. Licensed plumbers and pipefitters typically install this fitting during new construction and remodel work on potable water and radiant heat systems.

This coupling is suited for residential and light commercial plumbing installations where PEX-A tubing is the specified pipe material. It is commonly used at distribution manifold branch connections, fixture rough-ins, and inline reductions in hot and cold water supply piping. The 3/4 inches to 1/2 inches size reduction is one of the most common transitions in residential plumbing layouts.

Key Features

• Reduces from 3/4 inches to 1/2 inches for common branch and fixture supply transitions
• PEX-A compatible insert design for use with expansion-style installation tools
• Poly construction resists corrosion, scale, and chemical degradation
• Single-unit order increment allows precise procurement without minimum quantity requirements

Compatibility

Designed as an OEM-style insert coupling for use with 3/4 inches and 1/2 inches PEX-A tubing in potable water and hydronic plumbing systems.

Installation Notes

Installation is performed by a licensed plumber using a PEX-A expansion tool and appropriate expansion rings sized for 3/4 inches and 1/2 inches tubing. Shut off the water supply and relieve system pressure before cutting into any existing line. Follow local plumbing codes and IPC guidelines for PEX fitting installation, including required support intervals and minimum bend radii. Do not use this fitting with PEX-B or PEX-C tubing, as the insert expansion method is specific to PEX-A.

Technical Specifications

• Inlet Size: 3/4 inches
• Outlet Size: 1/2 inches
• Connection Type: PEX-A Poly Insert
• UPC: 811734022585

Standard Information

• Brand: AY MCDONALD
• Manufacturer Part Number: 4423-376