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Tue Jan 22 2019

Deublin Rotating Unions

By Norman G. Clark

Norman G. Clark - Rotating Unions are used in many manufacturing processes to cool, heat or transfer fluid (pneumatic or hydraulic) power.

Typical rotating unions feature deep groove ball bearings to support the rotating component against the stationary component and balanced, precision-engineered mechanical seals to seal the media flow.

Deublin rotating unions vary for each application, depending on design, bearing type, construction and material required.

Precise tolerances are critical to a rotating union’s performanceand longevity. To achieve these tolerances, Deublin uses the most advanced machining techniques and equipment in the industry.

Rotors and other components are tuned on state-of-the-art bar machines. As part of our commitment to quality control, all thread-cutting operations are closely monitored and tested to match your exact specifications.

Consistency in threading protects against union “wobble”, which can cause premature wear, resulting in costly parts damage and production downtime.


A rotating union must be capable of containing very high pressures while rotating at very high speeds. Smooth, easy rotation can only be achieved by exactly mating the seal faces to minimise friction.

All Deublin seals have a surface finish of 4 RMS and are micro-lapped to an optical flatness of better than 2 light bands or 0.000023” for dependable, leak-proof operation. Seals are then enclosed in housings that are machined on CNC turning machines to provide essential part-to-part precision.

Balanced Mechanical Seal

The greater the pressure on a rotating seal face, the greater the friction, torque and wear on theunion. That’s why Deublin Rotating Unions feature ”balanced mechanical seals”.

With this technology the thrust load or seal face contact pressure is kept to a minimum regardless of media pressure. This reduces wear, resulting in longer seal life. The spring-loaded seal is keyed so that it cannot rotate or creep, which can cause premature failure in secondary seals resulting in a leaking union.

Extended Life Sealing

Responding to ever-increasing speeds and pressures, Deublin Pioneered Extended Life Sealing (ELS) rotating unions offer outstanding performance under the toughest conditions, and can extend service life two to four times, depending on the severity of the application.

ELS unions use advanced materials such as tungsten carbide and silicon carbide to provide the best possible seal solution for the application.

Where reliability is of prime importance, ELS should be specified to protect against contaminants and redidt wear caused by rust, scale, chips and other harmful abrasives.

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