A rotary joint (or swivel joint) is a device used to transfer fluid under pressure or vacuum from a fixed inlet to a rotating outlet, maintaining and isolating the fluid connection.
Also referred to as a rotary manifold, swivel joint, rotating joint, rotary coupling, fluid swivel or fluid rotary union (FRU).
Rotary unions are engineered for each unique application taking into consideration media types, number of flow paths, temperatures, pressures, speeds, loads, and environments.
A rotary union functions by connecting a stationary input (supply) to a rotating part, allowing a moving connection to be preserved and permitting the flow of media (liquids, solids and gases).
Rotary unions are utilized in a wide range of industries, from compact rotary unions for semiconductor applications, to large and rugged-duty rotary unions for energy, defense and industrial applications.
Primary Components
Shaft
Bearings
Seals
Housing
Retaining Ring
Fluid Sealing & Transfer
Rotary unions (swivel joints) may integrate multiple independent flow channels (passages) for the sealing and transfer of different types of fluid media simultaneously. Common media types include:
Chemicals
Coolants
Food Products
Gases
Oils
Steam
Water
Rotary joint classification
Rotary couplings can be classified according to different application solutions: Single Passage Hydraulic Fittings, Low-speed hydraulic couplings, Low-speed multi-channel hydraulic couplings, Multi-Channel Hydraulic Fittings. Any type of rotary couplings can be produced by CSIequipt.
Single Passage Hydraulic Fittings
Reliable hydraulic rotary joints for high speed, high pressure applications are available in a variety of mounting configurations. Hydraulic couplings are available in a variety of sizes to fit small spaces, but are designed for harsh environments.
Low-speed hydraulic couplings
CSIequipt reliable low speed rotary joints designed to withstand harsh environments.
Low-speed multi-channel hydraulic couplings
CSIequipt's multimedia rotary joints are designed with separate channels to transfer hydraulic fluid and other media without cross contamination. Each application is unique. Whether you need a standard rotary union or a custom solution, CSIequipt's team of experts can provide a reliable and efficient solution.
Multi-Channel Hydraulic Fittings
Two-channel hydraulic rotary joints are designed to be used only with the same media, as this will extend seal life and prevent internal channel leakage.
Operating Parameters
Speed
Normal rotational speeds range from 0 to 1,000 RPM, with some high-speed rotary union applications requiring 10,000+ RPM.
Pressure
Normal pressures range from 0 to 20,000 PSI [1,380 BAR], with some rotary union applications pushing the range of 40,000+ PSI [2,760 BAR].
Temperature
Normal environmental and media temperatures for rotary union applications range from -150° F to +400° F. [-100° C to 200° C].
Application Example
Hydraulic Excavator
Speed: 15 RPM
Pressure: 3,000 PSI [207 BAR]
On an excavator, rotary unions allow hydraulic fluid to be transferred between the cab and track base while continuously rotating 360 degrees. The fluid supplies the track drive system allowing the excavator to move.
Wind Turbine
Speed: 20 RPM
Pressure: 5,000 PSI [345 BAR]
On a wind turbine, rotary unions supply hydraulic fluid to power the turbine's blade pitch control system used to maintain optimum blade angle to achieve efficient power output. Rotary unions integrate hydrodynamic seal technology to provide long-life, maintenance-free operation required for wind turbines in offshore environments.
Offshore Hose Reel
Speed: 10 RPM
Pressure: 20,000 PSI [1,379 BAR]
On an offshore hose reel, rotary unions (integrated with electrical slip rings) transfer hydraulic fluid, data and power signals through the reel hose down to subsea equipment. In some applications, pressurized hydraulics, power and data supply remotely operated vehicles (ROVs), allowing the control of subsea tools.
Hydraulic rotary joint solutions
CSIequipt rotary joints reliably seal and transfer fluid such as water, air, hydraulic oil, coolant, steam, and other media types from stationary sources to rotating parts.
Our rotary joint products are used across a wide range of industries including factory automation, heavy equipment, machine tool, packaging, medical, oil and gas, defense, and aerospace.
We offer standard rotary joint product lines grouped by function and feature exclusive sealing technology selected for compatibility to each application’s operating pressure, temperature, speed, media, and required service life.
If our inventory of standard products isn’t a fit for your project, we can provide a custom-tailored rotary joint solution designed to meet your exact application’s requirements for operating performance, cost, and delivery - in fact, it’s what we do best! Our fluid sealing experts will assist with a solution that meets your needs, which may include making modifications to a standard product, providing improvement recommendations to an existing design, or developing a new prototype to your exact project’s specifications.
Flexible solutions for hydraulic rotary joints with a variety of options to fit your media, pressure, speed, and temperature requirements.
Media Type
Oil/Hydrauli...
Air/Gas
Chemical
Coolant
DI/Tap Water
Food-Grade
Oil/Hydraulic
Steam
Water/Glycol
Other
Flow Passages
1 Passage
2 Passages
3 - 4 Passages
5 - 6 Passages
7 - 8 Passages
9 - 10 Passages
11 - 12 Passages
Over 12 Passages
Max. Pressure
Vacuum
0 - 200 PSI [0 - 15 BAR]
201 - 600 PSI [15 - 40 BAR]
601 - 5,000 PSI [40 - 345 BAR]
5,001 - 7,500 PSI [345 - 515 BAR]
7,501 - 20,000 PSI [515 - 1,375 BAR]
Over 20,000 PSI [1,375 BAR]
Max. Speed
0 - 50 RPM
51 - 75 RPM
76 - 300 RPM
301 - 500 RPM
Over 500 RPM
Flow Passage Size
Under 1/8" [3.18mm]
1/8" - 3/16" [3.18mm - 4.76mm]
1/4" - 3/8" [6.35mm - 9.53mm]
1/2" - 3/4" [12.70mm - 19.05mm]
7/8" - 1" [22.23mm - 25.40mm]
1-1/4" - 1-1/2" [31.75mm - 38.10mm]
2" - 3" [50.8mm - 76.20mm]
Over 3" [76.20mm]
Rotary Joint FAQs
What is a rotary joint?
A rotary joint (or rotary union) is a device used to transfer fluid under pressure or vacuum from a stationary inlet to a rotating outlet, preserving and isolating the fluid connection.
How do I choose a rotary joint?
Proper selection of a rotary joint solution requires details about your application's operating parameters including pressure, speed, media type(s), number of flow passages (channels), and connection size(s) / type(s). A good place to start your search is with our Standard Rotary Unions.
What is your process for a custom rotary joint solution?
First, contact us to Get Started. Our team will reach out to you to start learning more about your project's technical and delivery requirements. We will consider all aspects of your application and work together to develop the best solution. We typically start by evaluating our in-stock standard product options, reviewing our extensive library of custom rotary joint designs, and examining a complete custom solution.
We will present a detailed proposal including proposed design, cost breakdown, and project timeline. You will be assigned a sales engineer and project manager so you know who to go to with any questions throughout the process.
Do you offer compatible options for replacing another manufacturer's rotary joint?
Yes, we can cross reference other manufacturer's rotary joints to find an equivalent solution.
Can your standard rotary joints be modified to meet the requirements of my application?
We can modify our standard rotary joints to fit your needs. Custom modifications to our standard products are quite common and easier than you may think. Modifications include changes to housing / shaft dimensions and materials, seal types, mounting configurations, connection sizes and types, and flow passage configurations.
Do you offer replacement seals and/or bearings for rebuilding your rotary joints?
Yes, seal and bearing kits are available for our rotary joint products for on-location rebuilding and repair.
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