A rotating union connects a stationary pressurised supply line to a rotating machine part such as a cylinder, roll, spindle, clutch, etc. It can be used to convey virtually any liquid or gas: steam for heating, water or water/glycol solutions for cooling, hydraulic fluids, cutting fluids, air, inert gas, or even vacuum.
The task becomes more complicated when more than one media must be conveyed simultaneously. This is the role of a multi-passage union – to provide multiple, independent passages for the same or several different media to different rotating feed points within the same axis.
Typically, each passage is isolated from all other passages and different media are not allowed to mix. The key to reliable function of a multi-passage union thus lies in the sealing technology. Different seal types are dictated by the operating conditions – temperature, pressure, rotation speed, torque, medium chemistry and passage size.
Typical Applications for Multi-Passage Unions
- Steel industry: ladle turrets for continuous casting operations
- Plastics & rubber industries: injection and rotary molding operations
- Machining operations: workholding and clamping functions
- Aerospace manufacturing and flight simulators
- Industrial cranes
- Rail transportation
- De-scaling operations…and many more
Deublin Multi-Passage Sealing Solutions
Deublin Multi-Passage Soft-Seal rotating unions are optimised for the operating parameters of the application such as speed, torque, media pressure, operating temperature, physical size and other factors. Hardened chrome sealing surfaces are standard to ensure minimal wear and long service life.
Deublin Product Definition
Deublin Multi-Passage Soft-Seal rotating unions can be used in the widest variety of applications and media. Typical media includes the following:
- Hydraulic Oil
- Air (dry/lubricated)
- Cutting Oil
For media not listed above, please contact Deublin.
Deublin offers Multi-Passage Soft-Seal rotating unions that are standard, semi-custom and custom. When possible, Deublin recommends standard models, but will recommend semi-custom or custom models depending on the unique requirements of each application.
Semi-Custom unions can have different port sizes on the same union, SAE port connections and/or larger center bore (up to 50 mm). Custom unions have no limitation on dimensions, port sizes, port connection specifications and center bore dimensions.
- Ports/Passages: 2 to 8
- Sizes: 1/8” to 1/2”, NPT or BSP
- Optional center bore up to 25 mm (1”) for electrical slip ring wires
Materials of Construction
- Flanged rotor: AISI 420 with aluminum housing
- Bearings: dual, widely-spaced ball bearings ensure smooth running and minimize impact of potential side-loading
Examples of Applications
Deublin designs and manufactures a complete range of rotating unions from simple, single channel models used to prevent flex-hoses from twisting, to 12-port unions used on machine tool index tables, to massive, multi-channel unions used for ladle turrets in continuous casting machines. Deublin Multi-Passage Soft-Seal unions are used in applications that may require air, water, oil, grease, argon and other media.