Kadant Johnson Inc., a subsidiary of Kadant Inc. (NYSE:KAI), has expanded its existing line of rotary unions with the introduction of the Over-The-Shaft (OTS) rotary union for water-cooling. The OTS union is custom-designed for machinery that requires cooling on the drive side of driven rolls and for rolls that cannot accept an axially-mounted rotary union. This rotary union is available with a tungsten-carbide mechanical seal or a Quad-Seal o-ring design.

The mechanical seal version of the OTS union is intended for high speed applications up to 750 RPM. The precision ball bearings are widely spaced while the springs are located external to the flow area.

The soft seal version of the OTS union, designed for slower speed applications, uses a Quad-Seal o-ring and thrust washer. This seal package has been proven in thousands of process applications since 1991.
        
Both versions are constructed with stainless steel and bronze components. In addition to water cooling applications, the OTS union can be applied to hydraulic oil and air applications. It is rated up to 220 degrees F, 150 psig, and 750 RPM.