A rotary joint, also called a rotating union or swivel, permits fluid to flow from a stationary supply pipe into and out of rotating equipment. Fluids typically used with rotary joints and rotating unions include steam, water, thermal oil, hydraulic oil, air, and coolant.
Expansion joints provide relief from stresses caused by mechanical and thermal expansion and contraction in pipelines due to varying ambient temperatures, varying temperature of materials handled, and pipeline material composition. Expansion joints mitigate the risk of piping buckling, pulling apart, and causing excess vibration and noise.
