Single-passage GD and single-passage GDP rotary unions feature permanently closed sealing surfaces. The unique seal is compatible with all conventional media and even allows for unlimited dry machining, reducing leakage to a minimum. The high-quality built-in hybrid bearings have low coefficients of friction and a longer grease service life, allowing them to guarantee long-term functionality at high speeds. A labyrinth seal effectively protects the bearing against contamination, helping to maximise its life span. The coolant connection can be rotated up to 360° to make it easier to install. All GD rotary unions are available with radial and axial connections. Maintenance cycles can be calculated, which ensures optimal availability. Single-passage GD and single-passage GDP rotary unions feature permanently closed sealing surfaces.