Nibco B257100 Cast Copper Union 3/4 Inch Ftg X F

Product Description

The NIBCO B257100 is a 3/4 inch cast copper pipe union designed for pressure fitting applications in copper piping systems. It features a FTG x F (sweat fitting by female) end connection, allowing a soldered joint on the fitting end and a threaded or union nut connection on the female end. This union enables sections of copper pipe to be disconnected and reconnected without cutting, making it a practical choice for service points in potable water, HVAC hydronic, and plumbing distribution systems. Plumbers and pipefitters install this fitting where future serviceability is required. It meets ASME B16.18 and ASTM B584 standards for cast copper alloy fittings.

This union is suited for residential and light commercial plumbing and hydronic heating applications. The 3/4 inch size fits standard 3/4 inch copper tubing and is commonly installed at equipment connections, shutoff points, and anywhere a future break-apart joint is needed in a pressure system. The FTG x F configuration works with standard sweat soldering practices used in copper piping installations.

Key Features

• Cast copper construction per ASTM B584 for durability in pressurized water and hydronic systems
• FTG x F end connection supports sweat-soldered assembly on the fitting end
• Union design allows the joint to be broken and remade without cutting pipe
• Meets ASME B16.18 standard for cast copper alloy solder-joint fittings
• 3/4 inch fitting size compatible with standard 3/4 inch copper tubing

Compatibility

Designed as an OEM-style pressure fitting replacement for use in standard 3/4 inch copper tubing systems where a sweat union connection is required.

Installation Notes

Installation should be performed by a licensed plumber following local plumbing codes and IPC guidelines. Shut off the water supply and fully depressurize and drain the line before soldering. Clean and flux all mating surfaces prior to applying heat, and allow the joint to cool fully before restoring pressure. Inspect the union nut seat and sealing surfaces for damage before assembly.