Nibco, Inc. 771-LF Class 150 Companion Flange 2-1/2 In

2-1/2 Inch Class 150 Companion Flange

The Nibco 771-LF is a bronze sweat fitting adapter designed to join 2-1/2 inch copper tube to a flanged connection. It suits plumbing and HVAC installations carrying air or non-potable water up to 269 psi and 200 degrees Fahrenheit. The Class 150 rating matches standard low-pressure piping systems. This lead-free bronze body meets current drinking-water safety standards for non-potable circuits.

Sweat installation with four-bolt flange

Slide the cup end over clean 2-5/8 inch OD copper tube and solder using lead-free alloy for a permanent joint. The flange face measures 7 inches across with four 3/4 inch bolt holes on a standard pattern and 9/16 inch thickness for gasket seating. Common issues include overheating the bronze during soldering, which can warp the flange face, and misaligned bolt holes that stress the joint when tightened.

Pressure and temperature headroom

Rated for 269 psi at 200 degrees Fahrenheit, the flange handles typical hydronic heating, cooling and compressed-air lines with comfortable margin. It runs out of headroom in high-pressure steam service or systems that exceed the Class 150 pressure class. The four-bolt pattern limits mechanical restraint compared to heavier flanges, so vibration-heavy runs need additional support.