Matco-norca dun-1259 Dielectric Union 1-1/4 in Copper Sweat X Fpt

Product Description

The MATCO-NORCA dun-1259 is a lead-free dielectric union designed to connect copper sweat (solder) piping to female NPT-threaded pipe in residential and commercial plumbing systems. Sized at 1-1/4 inches, it uses a Sweat x FPT end configuration that mates directly to soldered copper on one side and an internally threaded fitting or valve on the other. Its dielectric barrier isolates dissimilar metals in the piping system, preventing galvanic corrosion at the transition point. Licensed plumbers and pipefitters install this fitting wherever copper meets iron or steel pipe, particularly at water heater, boiler, and meter connections. The lead-free construction meets current potable water standards.

This dielectric union is suited for residential and light commercial plumbing installations where a copper distribution system transitions to threaded iron or steel components. Common applications include water heater supply and return connections, boiler piping tie-ins, and service meter outlet connections. The union design allows the joint to be broken and remade without cutting pipe, making future service and component replacement straightforward. It is appropriate for use in domestic cold and hot water supply lines where lead-free materials are required by code.

Key Features

• Dielectric barrier separates copper and ferrous pipe to stop galvanic corrosion
• 1-1/4 inch Copper Sweat x Female NPT end connections
• Lead-free construction meets NSF and plumbing code requirements for potable water
• Union body design allows disassembly and reassembly without cutting into the line
• Weighs 0.84 pounds — compact and easy to handle in tight mechanical rooms

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/4 inch copper sweat to female NPT threaded connections in residential and commercial potable water plumbing systems.

Installation Notes

Installation is performed by a licensed plumber. Shut off the water supply and depressurize the line before soldering or threading. Follow IPC and local plumbing code requirements for dielectric isolation at dissimilar-metal joints. Do not over-tighten the threaded connection; use appropriate thread sealant or PTFE tape on the FPT joint and ensure the solder joint is fully cleaned and fluxed before applying heat.

Technical Specifications

• Fitting Size: 1-1/4 inches
• Connection Type: Copper Sweat x Female NPT (FPT)
• Type: Dielectric Union
• Lead Free: Yes
• Item Weight: 0.84 pounds

Standard Information

• Brand: MATCO-NORCA
• Manufacturer Part Number: dun-1259