Swivel joints are used in fluid and pneumatic systems that require torsional rotation between flow lines. They provide 360-degree rotation in 1, 2 or 3 planes and are usually made of forged materials. Some swivel joints use ball bearing raceways for better load distribution and spring-loaded seals to reduce torque drag. There are three basic types of swivel joints: straight-through, right-angle, and offset. Straight-through swivel joints are designed for applications in which the flow paths are coaxial. Right-angle swivel joints are used when the outlet ports are perpendicular to the inlet ports. Offset swivel joints combine a straight-through design with a 90-degree elbow integral to each end. In general, available space and fluid line routing determine the type of swivel joint that should be used.