1-1/4 inch Dielectric Union Female x Copper

1-1/4" Dielectric Union – Female Iron Pipe x Copper Sweat Connection

The 1-1/4 inch Dielectric Union Female x Copper is a specialized fitting designed to join dissimilar piping materials—typically ferrous (steel or iron) and non-ferrous (copper)—while preventing galvanic corrosion. This union features a female NPT threaded end and a copper solder end, separated by a non-conductive insulating barrier to electrically isolate the metals and extend system longevity.

Material Construction and Design

This dielectric union includes a steel or galvanized iron body on the threaded end, a brass or copper alloy fitting on the sweat side, and a thermoplastic or elastomeric insulator. A sealing washer and union nut provide a removable yet watertight mechanical joint suitable for hot and cold potable water systems and hydronic applications.

• ✅ Electrochemical Isolation Prevents galvanic interaction between copper and ferrous piping.
• ✅ Lead-Free Compliant Manufactured in accordance with NSF/ANSI 61 and 372 standards for use in potable water systems.
• ✅ Serviceable Design Union connection allows for disassembly during equipment maintenance or system modifications.
• ✅ Corrosion-Resistant Components Non-metallic insulator and zinc-coated or stainless hardware extend operational lifespan.

Technical Specifications

• Nominal Size: 1-1/4 Inch
• End Connections: Female NPT x Copper Sweat
• Pressure Rating: Typically 200–300 PSI (verify per manufacturer)
• Temperature Range: Up to 180°F for potable water systems
• Compliance: Conforms to ASTM, ANSI B1.20.1 (threads), and NSF/ANSI standards

Installation Notes

Install using appropriate joint sealant or PTFE tape on threaded connections. Sweat the copper end using lead-free solder and approved flux. Take care not to overheat the insulating barrier. The union nut should be tightened to specification using a properly sized wrench to prevent leakage or misalignment.

Typical Use Cases

Installed in domestic hot and cold water systems, commercial plumbing lines, and boiler connections where steel or iron piping must interface with copper tubing. Also used in mechanical systems to isolate brass or copper valves from galvanized distribution piping.

Application Insight

Dielectric unions are a critical component in mixed-material piping networks to mitigate corrosion caused by electrochemical reactions. Their use is often required by code when transitioning between ferrous and non-ferrous systems.

The 1-1/4" Dielectric Union Female x Copper is a field-proven solution for corrosion control in potable and mechanical piping. Its mechanical reliability and protective insulation make it a standard in professional-grade installations requiring material compatibility and code compliance.