Rotary Joints and Unions are mechanical sealing devices that transfer fluids from stationary supply lines to rotating equipment. They can handle steam, water, thermal oil, hydraulic fluid, or air while maintaining a sealed connection during rotation. Common applications include dryer cans, heated rolls, drums, and spindles.
In steam service, a rotary joint delivers steam into a rotating cylinder while a syphon removes condensate through a separate flow path. Effective condensate removal supports consistent heat transfer and helps prevent flooding. Rotary joints are commonly used for steam dryer and heated roll applications.
Although the terms are often used interchangeably, rotary joints generally refer to heavy-duty designs for steam and heat-transfer applications. Selection depends on the media, pressure, temperature, speed, and equipment configuration.