Description

Modern industrial equipment often requires several independent fluid circuits to pass through a rotating interface simultaneously. A 4-passage rotary union is designed specifically for these applications, allowing multiple media channels to operate independently while maintaining reliable sealing and continuous rotation.

Unlike a single-passage rotary union, a four-passage design supports complex equipment layouts by reducing external tubing, minimizing installation space, and simplifying maintenance. Each passage is independently sealed to prevent media mixing and pressure interference, making the rotary union suitable for demanding automated production systems.

As a dedicated rotary union manufacturer in China, we design and manufacture four-passage rotary unions for OEM machine builders, automation integrators, and industrial maintenance companies worldwide.

The 4 Passage Rotary Union is a high-performance, multi-channel rotary joint specifically engineered to handle simultaneous fluid, gas, or air transfers through four independent passages. It features a cutting-edge design that sets it apart from conventional rotary unions. With four independent passages, this advanced device enables the simultaneous transfer of multiple fluids, such as hydraulic oil, coolant, air, and steam, without cross-contamination. This unique feature not only enhances the efficiency of your machinery but also reduces the need for multiple rotary unions, saving you valuable space and costs.​

Our 4-passage rotary unions are constructed using high-quality materials, including stainless steel, carbon steel, and alloy steel, to ensure exceptional durability and resistance to corrosion, wear, and high temperatures. The precision-machined components and tight tolerances guarantee smooth rotation and leak-free operation, even under the most demanding conditions. Additionally, the union is equipped with advanced sealing technologies, such as mechanical seals and lip seals, to provide reliable and long-lasting performance.​

Why Choose a 4 Passage Rotary Union?

A multi-passage rotary union provides several advantages compared with installing multiple individual rotary unions.

Independent Media Transfer

Each passage can transport a different medium, including compressed air, hydraulic oil, coolant, vacuum, or inert gas, depending on the application.

Compact Machine Design

Integrating four channels into a single rotary union reduces installation space, simplifies piping, and lowers the number of external connections.

Improved Equipment Reliability

Fewer hoses and fittings reduce potential leakage points and simplify routine maintenance.

Flexible Configuration

Different thread types, flow capacities, and sealing materials can be configured according to customer requirements.

Specification	Details
Number of Passages	4 Independent Channels
Media Types	Water, Oil, Air, Steam, Coolants
Operating Pressure	Up to 30 MPa (4,350 PSI)
Maximum Rotational Speed	Up to 10,000 RPM
Temperature Range	-40°C to 220°C (-40°F to 428°F)
Material Options	Stainless Steel, Brass, Aluminum
Seal Type	Mechanical Seals, O-Ring, Hydrostatic Seals
Mounting Options	Shaft Mounted, Flange Mounted

Key Features

Four Independent Passages

The rotary union features four distinct passages, allowing for simultaneous fluid transfer without cross-contamination. This design is crucial for applications that require multiple fluids, such as oil and coolant, to be managed independently.

High Pressure and Temperature Ratings

This rotary union handles pressures up to 7,000 PSI and temperatures ranging from -20°C to 100°C, performs reliably under demanding conditions, and is ideal for high-pressure hydraulic systems.

Durable Construction

Constructed from high-quality materials such as stainless steel and carbon steel, the SM Oil Distributor Rotary Union ensures longevity and resistance to wear, even in harsh environments.

Advanced Sealing Technology

Equipped with precision-engineered seals, this rotary union minimizes leakage and enhances reliability. The closed seal design ensures maximum operation under pressure while extending the lifespan of the unit.

Typical Applications

Industrial Robotics

Robotic systems often require multiple pneumatic and hydraulic circuits to rotate continuously. A four-passage rotary union enables simultaneous transfer of air, vacuum, and coolant without twisting hoses.

Rotary Indexing Tables

Rotary tables in automated assembly lines require independent fluid channels for clamping, cooling, and pneumatic control.

Battery Manufacturing

Battery production equipment uses several fluid circuits to support cooling, pneumatic positioning, and process control.

Semiconductor Equipment

Precision manufacturing equipment requires compact rotary unions capable of isolating multiple media while maintaining clean operating conditions.

Packaging Machinery

Packaging systems frequently combine compressed air, vacuum, and cooling circuits within rotating assemblies.

Plastic Processing Equipment

Injection molding and extrusion systems require reliable cooling and hydraulic transfer during continuous operation.

Common Challenges and Engineering Solutions

Challenge: Cross-Contamination Between Passages

Poor sealing design may allow media from one passage to migrate into another.

Our Solution

Each fluid channel is independently sealed with dedicated sealing interfaces to maintain separation under operating pressure.

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Challenge: Seal Wear Under Continuous Rotation

High rotational speeds accelerate seal wear.

Our Solution

We optimize seal geometry and recommend material combinations based on media compatibility, temperature, and rotational speed.

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Challenge: Uneven Flow Distribution

Improper internal passage design can result in pressure loss or inconsistent flow.

Our Solution

Internal flow paths are designed to reduce restriction while maintaining balanced fluid delivery across all passages.

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Challenge: Bearing Fatigue

Multiple fluid channels increase structural complexity and bearing loads.

Our Solution

Bearing selection is matched to the expected operating load, helping maintain stable shaft alignment during long production cycles.

Manufacturing Experience That Supports Long-Term Reliability

A four-passage rotary union is considerably more complex than a single-channel design. Internal passage isolation, machining accuracy, and assembly precision all influence sealing performance and service life.

For this reason, our manufacturing process places equal emphasis on engineering review, machining consistency, and functional verification.

Before production begins, our engineers evaluate customer drawings and operating conditions to determine whether a standard design or a customized configuration is more suitable. Parameters such as pressure, rotational speed, media type, flow rate, and installation space are reviewed to ensure the rotary union will operate reliably in its intended application.

Rather than relying on a universal design, we adjust sealing arrangements, bearing configurations, and passage layouts according to the actual requirements of the equipment.

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Precision Manufacturing Process

Every 4-passage rotary union is manufactured within our own production facility using CNC equipment and standardized inspection procedures.

The manufacturing workflow includes:

• Material preparation
• CNC turning
• Multi-axis machining
• Internal passage machining
• Surface finishing
• Thread inspection
• Seal installation
• Bearing assembly
• Functional testing
• Final inspection

Throughout the production process, dimensional accuracy is monitored to maintain proper alignment between rotating and stationary components.

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Functional Verification Before Shipment

Each finished rotary union undergoes multiple verification procedures before delivery.

Inspection items include:

• Dimensional measurement
• Thread verification
• Rotation smoothness
• Leakage testing
• Pressure testing
• Visual inspection
• Packaging inspection

For OEM projects, inspection records and additional documentation can be provided upon request.

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Practical Experience From OEM Projects

Our engineering team has supplied multi-passage rotary unions for customers involved in:

• Automated assembly systems
• Packaging machinery
• Machine tools
• Industrial robotics
• Semiconductor equipment
• Textile machinery
• Printing systems
• Food processing automation

Working closely with machinery manufacturers allows us to continuously improve product details based on practical operating conditions rather than theoretical assumptions.

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Engineering Collaboration

Selecting the correct multi-passage rotary union requires careful consideration of several factors.

Our engineers assist customers with:

• Passage configuration
• Seal material selection
• Connection design
• Pressure matching
• Speed verification
• Installation review
• CAD optimization
• Replacement for discontinued models

Early engineering collaboration helps reduce installation issues and shortens equipment commissioning time.

Why Choose Our 4-Passage Rotary Union?

At Dann, we are committed to providing top-tier solutions for all your rotary sealing needs. Here’s why our 4 Passage Rotary Unions stand out from the competition:

Expert Engineering & Precision Manufacturing

Our experts, with over 10 years of experience in the rotary union industry, design our products with a deep understanding of the intricacies of fluid and air transfer systems. We engineer our 4 Passage Rotary Unions for high performance, incorporating superior sealing technology that ensures leak-free operation in even the most demanding environments.

High Durability and Reliability

We build our rotary unions to last by using heavy-duty materials such as stainless steel, nickel-plated brass, and heat-resistant components. Whether your application involves hydraulic systems, pneumatic machinery, or coolant transfer, our unions deliver optimal reliability and long-term performance, reducing downtime and maintenance costs.

Versatile Applications

Designed for a wide range of industrial applications, our 4 Passage Rotary Unions are ideal for systems requiring multi-fluid transfer, including water, air, steam, and oils. These unions commonly serve in CNC machinery, automated equipment, and high-speed rotary systems. With multiple port options and the ability to handle varying flow rates, our products offer unmatched flexibility.

Customizable Solutions

We understand that each application is unique. That’s why we offer custom designs tailored to your specifications, including port sizes, pressure ratings, and seal materials. Our team works closely with you to ensure the perfect fit for your system, whether you require single-flow or dual-flow designs.

Competitive Pricing & Exceptional Value

We offer cost-effective solutions without compromising on quality. As a leading manufacturer of rotary unions, we can provide you with high-quality products at a fraction of the cost of major brands. Our affordable pricing makes us the perfect choice for both OEMs and bulk orders, ensuring great value for your investment.

Global Customer Support

Our commitment to customer satisfaction extends beyond the sale. We offer comprehensive technical support and engineering assistance to help you select, install, and maintain your 4 Passage Rotary Union. No matter where you are located, our team is ready to assist with installation guides, troubleshooting, and post-purchase services.

Fast Shipping & Delivery

We understand that timely delivery is crucial to your operations. With in-stock options and fast shipping, we ensure that your rotary unions reach you on time, ready for installation.

Choose Dann for your 4 Passage Rotary Union needs, and experience the perfect combination of reliable performance, competitive pricing, and exceptional customer service. Let us help you streamline your operations with our advanced sealing solutions.

Why Work With Our Factory?

Instead of acting only as a component supplier, we support OEM customers throughout the manufacturing process.

Our capabilities include:

• Custom machining
• Prototype production
• Flexible batch quantities
• Material traceability
• Stable machining standards
• CAD and 3D model support
• Export packaging
• Responsive technical communication

This approach allows customers to integrate our rotary unions into new equipment with greater confidence and predictable production quality.

Frequently Asked Questions

Can each passage carry a different medium?

Yes. Depending on the application, different passages can be configured for air, coolant, hydraulic oil, vacuum, or other compatible media while remaining independently sealed.

Can you customize the number of passages?

Yes. We manufacture rotary unions with one, two, four, six, eight, or more passages according to customer requirements.

How do you prevent internal leakage between channels?

Each passage uses an independent sealing arrangement designed to isolate media and maintain pressure integrity.

Do you support OEM manufacturing?

Yes. We manufacture according to customer drawings, samples, or technical specifications and provide CAD support for new equipment development.

Is pressure testing performed before shipment?

Yes. Functional testing and pressure verification are completed before products leave our factory.

Optimize Your Machinery Today!

Stop compromising with unreliable single-pass unions. Upgrade to a precision 4 Passage Rotary Union for seamless multi-line transfer, reduced downtime, and 99.5% leak-free operation.

📞 Contact Our Team: +86-15122592153
📧 Request Custom Quote: sales@dannhydraulic.com
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