The 2000 Series rotary unions from Duff-Norton, Charlotte, N.C., transfer air and fluids, including oil and water, from a stationary supply to a rotating component such as a drum or roll. They can be used to transport heating or cooling media like steam, hot oil, water, or coolant to control the surface temperature of a drum or roll, or to add fluids to mixers while in motion. This Series uses a pair of ball bearings spaced to withstand radial and thrust loads. The device maintains even loading across the seal to eliminate leaks even in low-pressure applications. A built-in flange lets technicians service the unit without removing the housing. Because the flange connects directly to the machine journal, it provides inherent concentric mounting, minimal overhang, and partially relieves bearing loads, all of which extend the service life. It can handle water up to 150 psi, air and hot oil to 100 psi, and turn at speeds to 500 rpm. It also withstands water at 327°F and oil to 550°F.