A pneumatic or hydraulic rotary union transfers pressurized media between stationary and rotating parts while controlling leakage, friction, heat and service life. Use this architecture when air, gas, oil, water or another fluid must cross the rotating interface.
Terminology: rotary union, rotary joint and swivel may describe fluid-transfer hardware; define media, pressure, flow, temperature, ports, speed and sealing environment.
Specifications to verify
The table below is a configuration checklist, not a blanket performance claim. Confirm the selected values against the approved drawing, test method and quotation for the exact assembly.
Configuration values are confirmed against the approved drawing, test method and quotation for the selected assembly.
Available configurations and selection guide
Rotary-union configurations are defined by media, pressure, flow, temperature, port geometry, seal material, speed, leakage target and mounting. Confirm the exact media compatibility and pressure test method.
Choose a pneumatic or hydraulic rotary union when air, gas, oil, water or another fluid must cross rotation. Compare an integrated assembly when electrical services must share the same rotary interface.
Compare through-bore, capsule and hybrid architectures against the machine envelope, circuit schedule and service requirements.
Approved product photograph
Add the original Slip Ring USA asset for this configuration before publication.
Approved dimensional drawing
Attach the approved drawing revision or link to a Slip Ring USA datasheet; do not substitute an unverified range image.
Applications and case-study evidence
Rotary unions are evaluated for packaging, machine tools, printing, filling, winding, process equipment and other rotating systems that need pressurized media transfer.
Datasheet status: request a Slip Ring USA-branded PDF with the RFQ so the document matches the exact configuration and drawing revision.
Engineering questions
What is a through-bore slip ring?
It is a rotary electrical interface with a hollow center that allows a shaft, cable bundle or other service to pass through while power, signals or data cross the rotating interface.
When should I choose through-bore instead of capsule?
Choose through-bore when the machine needs center routing, a larger envelope, or more complex mixed-service integration. Choose capsule when the assembly is compact and no center opening is required.
Can a through-bore slip ring carry power and data together?
Yes, when the circuit mix, shielding, impedance, contact system and test method are engineered for the required protocols and data rates.
What details determine service life?
Speed, direction changes, duty cycle, current, contact material, vibration, contamination, temperature and sealing all affect life. The target should be tied to a stated test condition and expected revolutions or years.
Can the center pass pneumatic, hydraulic or fiber services?
The bore can provide routing space, but a combined assembly must be checked for bend radius, sealing, pressure, flow, fiber alignment, mounting and rotational constraints. Use the family-specific RFQ fields to define those requirements.
Content owner: Slip Ring USA technical content team. Technical reviewer: assign a named engineer and qualifications before publication. Publication date: August 6, 2026. Last technical review: August 6, 2026. Review and update all configuration-specific claims against the approved drawing and test record.

