Glossary
Seal Face
The precision-lapped, smooth surfaces where the stationary and rotating seal rings meet. This is the most critical area for dynamic sealing, typically made from wear-resistant materials like carbon graphite, silicon carbide, or tungsten carbide.
Bellows
A flexible, spring-like component that acts as a compensation device. It absorbs axial runout, vibration, and installation misalignment while providing a consistent pre-load to the seal faces.
Single Passage & Multi-Passage
Refers to the number of flow channels. Single passage allows media to flow in only one direction (requires a siphon tube for return). Multi-passage allows separate inflow and outflow paths within one joint, ideal for independently controlled roll zones.
Siphon Tube
A tube installed inside the rotary joint or at the roll end. It is used to remove condensate (in steam systems) or used media from the bottom or far end of a rotating drum.
Spherical Alignment
A self-aligning feature (usually a spherical radius design) that compensates for the radial run-out and angular misalignment of the roll during operation, reducing internal stress and preventing seizure.
Dynamic Balancing
A precision correction process for the rotating housing of the joint. By measuring and correcting mass distribution on a balancing machine, it ensures vibration-free operation at high rotational speeds.
Labyrinth Seal
A non-contact sealing structure using a series of complex grooves to block solid contaminants (dust, debris) from entering the bearings while retaining grease.
Torque Arm / Anti-Rotation Device
A component that holds the stationary outer casing of the rotary joint in place, preventing it from rotating with the roll. It is usually attached to the joint and fastened to the machine frame.
Leakage Rate
A key performance indicator measuring sealing efficiency. It refers to the permissible volume of media passing through the seal faces per unit time under specific pressure (e.g., ml/min for air, drops/min for oil).