Nibco, Inc. 733-3 Cast Bronze Solder Pressure Copper Union 3/4 in

Copper union for 3/4 in solder joints

The Nibco 733-3 is a cast bronze union that joins 3/4 in copper tube to a female NPT thread. It is sized for a 7/8 in outside diameter tube and rated for 466 psi at 200 degrees F. Plumbers and maintenance crews use it where a removable joint is required on water, oil or gas lines.

Solder connection limits pressure and temperature

The C x FNPT configuration means one end is soldered to the tube while the other accepts a threaded pipe. The assembly handles temperatures from -20 to 400 degrees F, but the solder joint itself sets the practical ceiling well below the fitting's 466 psi rating. Installers must follow ASME B 16.18 procedures to keep the joint within its design envelope.

Cast bronze body resists corrosion and vibration

The bronze construction withstands aggressive water chemistry and mechanical stress better than brass alternatives. A ground-joint seat seals metal-to-metal without a gasket, so the union can be broken and remade repeatedly during service. The 3/4 in nominal size matches standard copper tube and NPT threading for direct compatibility with existing piping.