Nibco B305406 Cast Copper Companion Flange 1-1/4 in

Product Description

The NIBCO B305406 is a cast copper companion pipe flange rated for 125 psi service, designed for use in plumbing and piping systems where a secure, leak-free flange connection is required. Sized for 1-1/4 inch pipe with a 4-5/8 inch outside diameter, it features a C-style (solder cup) end connection for direct copper tube integration. The bolt hole centers are spaced 3-1/2 inches apart, conforming to standard flange bolt patterns. Fabricated from cast copper alloy and meeting ASTM B584, this flange is suited for installation by licensed plumbers in commercial and residential piping systems carrying water, hydronic fluids, or compatible liquids within the rated pressure class.

This companion flange is used in systems where two mating flanges must be joined face-to-face, such as pump connections, valve isolations, and equipment tie-ins. The solder cup end connection allows the installer to sweat the flange directly onto copper tubing using standard soldering practices. It is appropriate for residential and light commercial plumbing, hydronic heating, and process piping applications where cast copper construction and a 125 psi pressure rating meet the design requirements. The companion style means this flange is intended to pair with a matching flange on the opposing component.

Key Features

• Cast copper alloy construction per ASTM B584 for corrosion resistance in wet piping systems
• 125 psi pressure rating suitable for residential and commercial plumbing and hydronic applications
• C-style solder cup end connection for direct sweat attachment to copper tubing
• 1-1/4 inch pipe size with 4-5/8 inch OD and 3-1/2 inch bolt hole center spacing
• Companion flange style designed to mate face-to-face with a corresponding flange

Compatibility

Designed as an OEM-style replacement or new-installation companion flange for 1-1/4 inch copper pipe systems using Class 125 flange connections with solder cup end preparation.

Installation Notes

Installation should be performed by a licensed plumber in accordance with applicable local plumbing codes and IPC guidelines. Depressurize and drain the piping system fully before cutting into the line or removing an existing flange. Use appropriate flux and lead-free solder when making the sweat connection, and allow the joint to cool completely before applying bolt torque or restoring system pressure. Verify gasket selection and bolt grade are compatible with the service fluid and pressure class before returning the system to service.