Dual Passage Rotary Union for Printing Ink

Description

The Dual Passage Rotary Union is a high-performance rotary joint designed to transfer two independent media simultaneously between stationary pipelines and rotating equipment. It is widely used in printing ink systems, where multiple fluid channels—such as ink supply and return flow—must operate continuously without mixing or leakage.

Unlike single-channel rotary unions, dual passage designs enable parallel fluid transmission, significantly improving system efficiency and process stability. These rotary unions are essential in modern high-speed printing machines, ensuring consistent ink delivery, precise pressure control, and uninterrupted production.

A dual passage rotary union allows different media to flow through separate channels without cross-contamination, maintaining system integrity even under high pressure and rotation.

Key Advantages of Dual Passage Rotary Union

1. Dual Channel Independent Flow Design

• Two isolated flow passages for ink supply and return
• Prevents media mixing and contamination
• Improves system efficiency and control

This design is particularly critical in printing ink circulation systems, where stable flow directly affects print quality.

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2. High-Precision Sealing System

• Advanced mechanical seal technology
• Carbon graphite + ceramic/silicon carbide faces
• Excellent sealing performance with zero leakage

The sealing system ensures reliable operation even with viscous inks and chemical-based fluids.

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3. High-Speed Operational Stability

• Balanced rotor design minimizes vibration
• Supports high-speed printing equipment (3000–4000 RPM)
• Ensures smooth rotation and long-term durability

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4. Multi-Media Compatibility

Dual passage rotary unions support various media types, including:

• Printing ink
• Solvent-based fluids
• Cooling water
• Air or auxiliary fluids

Multi-passage rotary unions are specifically designed to handle multiple media simultaneously in rotating systems.

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5. Long Service Life & Low Maintenance

• High-quality bearings (ball bearing/graphite bearing)
• Wear-resistant sealing materials
• Reduced downtime and maintenance costs

Parameter	Specification
Number of Passages	2 (Dual Passage)
Connection Type	1/4"-18 NPT, BSPP, or SAE-ORB
Material	Stainless Steel, Carbon Graphite
Max Pressure	Up to 7,500 PSI (515 BAR)
Max Speed	Up to 500 RPM
Through Bore	0.375" to 0.75" (varies by model)
Length	Approx. 4.7" (varies by model)
Diameter	Approx. 3.7" (varies by model)
Min. Torque to Rotate	5.7 ft-lbs (7.73 Nm)

Our Manufacturing Strength

10+ Years Industry Experience

We are a professional rotary union manufacturer with over 10 years of experience, specializing in multi-passage rotary unions and printing industry solutions.

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Advanced Production Capability

• CNC precision machining centers
• Fully integrated assembly lines
• Monthly production capacity: 5,000+ units
• Strict 100% testing before shipment

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OEM & Custom Engineering

We provide:

• Custom dual passage designs based on drawings
• Replacement solutions for international brands (e.g., Deublin alternatives)
• Optimized solutions for printing equipment manufacturers

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Quality Assurance System

• Raw material inspection and traceability
• Dynamic balancing testing
• Pressure and leakage testing
• Long lifecycle validation

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Competitive Advantages

• Factory-direct pricing (cost-effective alternative)
• High interchangeability with global brands
• Fast delivery (3–7 days standard models)
• Strong customization capability
• Global export experience

Applications in the Printing Industry

The Dual Passage Rotary Union for printing ink is widely used in modern printing equipment:

Printing Ink Circulation Systems

• Offset printing presses
• Flexographic printing machines
• Gravure printing systems

Industrial Printing Equipment

• Label printing machines
• Packaging printing lines
• Textile printing systems

Other Industrial Applications

• Rotary drums
• Multi-fluid transfer systems
• Cooling + lubrication combined systems

In these applications, the rotary union ensures continuous ink transfer and return circulation, which is critical for maintaining consistent color density and print accuracy.

Why is the Dual Passage Rotary Union Essential for Printing Ink

In high-speed printing systems, ink must be continuously delivered and recycled. Without a dual passage rotary union:

• Ink supply becomes unstable
• Pressure fluctuations affect print quality
• Fluid leakage leads to downtime and waste

With our solution, you get:

• Stable ink circulation system
• Reduced ink waste
• Improved production efficiency
• Clean and leak-free operation

FAQ

Q1: What is the advantage of a dual-passage rotary union over a single-channel union?

A: A dual-passage (dual-flow) union carries two separate fluids or gases at once, saving space and simplifying design. Instead of installing two unions for ink and coolant (or ink and air), one H Series dual union handles both. This reduces potential leak points and maintenance. Overall, dual-flow unions boost system efficiency by integrating multiple media in one compact device.

Q2: What types of media can each channel carry?

A: Each channel operates independently, allowing you to use one for printing ink (either water-based or solvent-based) and the other for a different medium. Common combinations include ink plus water (for roll cooling), ink plus compressed air (for pneumatic controls), or ink plus cleaning solvent. The union’s seals are compatible with a wide range of fluids and gases. Always confirm chemical compatibility with the manufacturer, especially for aggressive solvent inks.

Q3: What are the operating limits (pressure, temperature, speed)?

A: Engineers designed the H Series dual rotary union for heavy-duty use. It typically handles pressures up to ~250 bar (3,625 psi) and temperatures up to ~250°F (121°C). Max rotational speed is around 3,500 RPM, depending on fluid type and port size. These ratings make it suitable for most high-speed printing applications. Refer to the specification table above for exact values and consult factory data for customized versions.

Q4: How is the H Series rotary union maintained?

A: Maintenance is straightforward. Routine checks for external leaks or unusual vibration are recommended. The union’s seals may need periodic replacement depending on usage. Most users report needing only occasional seal changes and lubrication due to its durable construction. External grease fittings and optional seal wear indicators simplify servicing, minimizing press downtime.

Q5: Can this rotary union be customized to specific needs?

A: Yes. The H Series design is modular. You can choose different housing materials (e.g., brass, carbon steel), port sizes, or threaded connections (NPT, BSP, etc.) to match your press hardware. Custom versions can also adjust pressure or temperature ratings for special applications. Work with the supplier to select the right options for your ink type, operating pressure, and mechanical mounting.

Conclusion

Our Dual Passage Rotary Union offers a reliable, efficient, and customizable solution for dual media transfer in rotating machinery. Designed with advanced sealing technology and robust materials, it meets the highest industrial standards for performance and durability. Optimize your pneumatic and hydraulic systems with this compact, leak-proof rotary union engineered for continuous operation and minimal maintenance.

Request a Quote

Looking for a reliable Dual Passage Rotary Union supplier for printing ink systems?

We offer:

• Fast quotation within 24 hours
• Custom engineering support
• Competitive factory pricing

Contact us today to get the best solution for your printing application.