Viega 79260 ProPress adapter 1-1/4" x 1-1/4" trap

ProPress adapter for potable water

The Viega 79260 ProPress adapter connects 1-1/4" copper tube to a 1-1/4" male NPT thread using a press-fit joint. It is intended for potable water systems in residential and commercial plumbing installations. Bronze construction with an EPDM O-ring provides corrosion resistance and a reliable seal without soldering or threading tools.

Capacity and headroom at 200 psi / 250 °F

The fitting is rated for a maximum operating pressure of 200 psi and a maximum operating temperature of 250 degrees Fahrenheit, covering typical hot and cold water distribution demands. It handles standard municipal pressures and recirculation loop temperatures without derating. Systems that exceed either limit — such as high-pressure booster zones or steam lines — require a different component rated for those conditions.

Practical limits of the press-fit standard

The press connection complies with ASTM B75 and ASTM B88, which govern the copper tube dimensions and material quality the joint relies on. The adapter will not seal on tubing that falls outside those standards, on non-copper pipe, or when the press tool jaws are mismatched to the 1-1/4" size. Threaded side engagement still depends on proper NPT threading practice and compatible mating fittings.