Rotating unions for water
Rotating unions for the supply and return of fluids
Technical data
Protection class
IP51 (higher on request)
Rotational speed
0-300 rpm
Housing material
Aluminium, Stainless steel
Number of implementations
1-24
Additional services
Combination of different feedthroughs
Media implementation specification
- Number of pneumatic/liquid feed-throughs: 1 – 24
- Connection sizes: M5, 1/8″, ¼”, 3/8″, ½”, 5/8″, 1″, 1¼”
- Straight or angled connections
- Pressure: up to 1300bar, 130MPa; 20000 psi, vacuum 0.01torr, 30HG
- Media: Compressed air/pneumatics, Vacuum, Hydraulic oil, Return oil, water, hydrogen, nitrogen, vapour, cooling water, coolant, hot water, acids, bases and much more
Product overview
All details about our slip rings can be found in our product overview
Single and multi-channel rotary feedthroughs for water
Unlike electrical Slip rings for power, signal and data transmission, classic single-flow and multi-flow rotary feedthroughs do not have the task of exclusively transmitting signals and current between fixed and rotating components. Instead, they enable the sealed transition of one or more fluids between stationary supply lines and/or rotating components (against each other). They are therefore primarily used for rollers, spindles and motors.
One of the most frequently transferred fluids is water. However, it is often also the least complicated, as the transfer of acids, greases or other fluids is subject to more stringent requirements, particularly in terms of sealing and corrosion resistance. Incidentally, rotarX also offers rotary feedthroughs for transferring a vacuum or gases and compressed air (pneumatic and hydraulic energy).
Electrical rotary feedthroughs are also available for the combined transmission of media, electricity and, if necessary, control signals and data.
Functionality of rotating unions for water
Rotating unions usually consist of a fixed and a rotating component. The stationary component is connected to the water supply, while the rotating component is connected to the rotating part of the machine. There is a seal between these two components to prevent water from escaping. Thanks to the precise design and high-quality materials of the seals, rotating unions can function reliably even at high speeds and under pressure.
Rotary union
Choice of different housing materials
Various connection sizes for media feed-throughs
Mounting and bolt circle rotor
Optional rotary feedthrough with hollow shaft
Where are rotating unions for water used?
They can carry not only cold cooling water, but also heating water, waste water, steam or several media in combination.
Rotating unions for water are therefore used in a wide range of industrial applications, including:
- Packaging industry: In the packaging industry, rotating unions are used to cool machine parts during the printing and packaging process.
- Metalworking: In metalworking, they are used to cool cutting tools during the milling or turning process, which increases the service life of the tools and enables a better surface quality of the machined parts.
- Paper industry: In paper manufacturing, rotating unions enable the cooling and lubrication of rolls, which is crucial for the quality and speed of the paper manufacturing process.
- Chemical industry: In chemical processes, they are used to cool or heat reaction vessels or mixers, enabling precise control of process temperatures.
- Power generation: In hydroelectric power plants, rotating unions enable the transfer of cooling water to rotating parts of turbines.
Advantages of rotating unions
- Reliability: They provide a reliable solution for transferring fluids into rotating systems, which increases operational safety.
- Efficiency: Effective cooling or lubrication allows processes to be designed more efficiently, resulting in energy savings and a longer service life for machine parts.
- Flexibility: Rotating unions are available in different sizes and for different pressure ranges, allowing them to be used in a wide range of industrial processes.
Rotary unions for water are therefore indispensable components in many industrial applications. Their ability to safely and efficiently transfer fluids from a stationary to a rotating system makes them a key technology in areas that require continuous cooling, lubrication or fluid supply. The selection of the correct rotating union and regular maintenance are critical to ensure the performance and reliability of these important components.
Rotating unions for hot water
Rotating unions that transport hot water are used in various industries, primarily for heat transfer, process heating or cleaning. Here are three detailed examples of industries in which hot water is moved through rotating unions:
1. Food and beverage industry
In the food and beverage industry, rotating unions play a crucial role in the heat treatment of products, the cleaning of systems and sterilisation. Hot water is used, for example, to bring raw materials to the correct processing temperature or to pasteurise products after processing. Rotating unions enable the continuous supply of hot water to rotating drums or containers used for cooking, brewing or mixing ingredients. In addition, hot water is used for CIP (Cleaning in Place) cleaning procedures to clean and sanitise equipment and pipework without having to dismantle them. This helps to maintain strict hygiene standards and prevents food contamination.
2. Paper industry
In papermaking, the use of hot water is essential for several process steps, including pulp preparation and sheet formation. Rotating unions are used to direct hot water to the rotating parts of the machines used to prepare the pulp and clean the screens and rolls. Hot water helps to loosen and clean the fibres, which is crucial for the quality of the end product. Hot water is also used in the paper industry for thermal drying of the paper webs, with rotating unions ensuring a continuous supply of hot water or steam to the drying cylinders. This step is crucial for the strength and texture of the finished paper.
3. Textile industry
The textile industry uses hot water for various processes, including dyeing, washing and thermal treatment of fabrics. Rotating unions allow hot water to be supplied to the dyeing or washing machines, which rotate or shake to ensure even treatment of the textiles. Hot water is crucial for dissolving the dyes and distributing them evenly throughout the fabric, as well as for washing out chemicals and excess dyes after the dyeing process. In thermal treatment, hot water is used to condition the fabrics and improve certain properties such as shrink resistance and colour fastness. Rotating unions contribute to the efficiency and uniformity of the processes.
Multi-channel rotary feedthroughs for water and other fluids
Multi-channel rotary unions are complex mechanical devices that can simultaneously transfer different media – such as liquids, gases or vapour – from a stationary to a rotating system. This type of rotating union is required in industrial applications where several process steps are carried out simultaneously or different media are required for the operation of a machine or system. Here are some detailed examples that illustrate the necessity and application of multi-channel rotary unions:
1. Plastics and rubber processing
In plastics and rubber processing, multi-channel rotary unions are used to simultaneously feed cooling water, hydraulic oil and compressed air to the rotating moulds or extruders. Cooling water is required to quickly cool the moulds or material after processing, hydraulic oil is used to drive the machine movements, and compressed air is used for cleaning or as part of the moulding process. The ability to feed all these media simultaneously through a single rotary union optimises the production process, reduces the space required for machine installation and improves the efficiency of the energy and media supply.
2. Printing and paper industry
In the printing and paper industry, multi-channel rotary unions are required to supply printing machines or paper manufacturing machines with a combination of steam, cooling water and compressed air. Steam is used to heat certain parts of the machine or for the drying process of the paper, cooling water is used to control the temperature of critical components, and compressed air is used for pneumatic controls and cleaning tasks. The simultaneous supply of these media through a multi-channel rotary union enables precise control of production conditions and contributes to quality assurance.
3. Food industry
In the food industry, multi-channel rotary feedthroughs are used to supply processing machines with hot water, steam and cooling media. Hot water and steam are essential for sterilisation and cooking processes, while cooling media are required for the rapid cooling of food after processing or for temperature control during production. The combination of these media in a multi-channel rotary union enables production processes to be organised flexibly and efficiently.
What is important for a multi-channel rotary feed-through
Several factors are decisive when selecting and using multi-channel rotary feedthroughs:
- Media compatibility: The materials of the rotating union must be compatible with all the media conveyed in order to avoid corrosion or chemical reactions.
- Seal quality: High-quality seals are essential to prevent cross-contamination between the channels and leaks to the outside.
- Temperature and pressure resistance: The rotating union must be able to withstand the operating temperatures and pressures of all media.
- Ease of maintenance: Simple maintenance and quick replacement of wearing parts are important to minimise downtimes.
Multi-channel rotary feedthroughs are therefore critical components in many industrial applications that enable the efficient and reliable transmission of several media simultaneously.
Your path to customised turning
The basic prerequisite for the optimum solution is a detailed consultation. Together we define the framework conditions, specifying the required media and operating data. We need information from you on detailed process sequences, e.g. when which medium is pressurised, temperature influences, space conditions, but also the range of channels required, which must be variable depending on the user, for example on permanently installed workbenches (with milling machines or other tools). In this case, a central interface for media and power feed-through in a modular design is required.
It all depends on the seal
Our main concern when developing our technology and providing individual advice is to ensure a high level of operational readiness while simplifying installation, minimising maintenance requirements and at the same time ensuring a long service life. Achieving these goals is much more challenging for pneumatic rotary feedthroughs with standard or combined electrical media transmissions than for purely electrical slip rings or simple rotary feedthroughs. This is due in particular to the challenges associated with sealing and wear caused by friction.
The precise separation of the various media channelsand wear on the seals pose the greatest design challenges. The rotation between the inner and outer housing leads to continuous friction, which is less of a problem with purely electronic slip rings. However, in applications where absolute tightness is required, the wear of rubber rings on plastic or aluminium is a limiting factor for the service life of the component. At rotarX, we have already successfully overcome these and other challenges for various industries.
The secret of our success lies in the use of balanced mechanical seals. In pneumatic or hydraulic rotary feedthroughs, for example, these ensure that only the actuating and restoring forces act on the seals rather than the full operating pressure, which leads to a significant increase in service life. In addition, we offer various seal ring materials such as ceramic, graphite or silicon carbide on request in order to be able to optimally meet the specific requirements of our customers. This helps to reduce maintenance costs and minimise friction on the seals.
Why RotarX?
Our many years of experience pay off when it comes to the special challenges of designing hybrid rotary feedthroughs. Our modular design principle and customised advice from our experts based on your process parameters and environmental requirements enable over 50,000 different possible combinations.
Compared to pure power or fluid feedthroughs, passing gas pressure or hydraulic pressure through a rotary joint is an enormous challenge. A complex channel system is created between the rotor and the stator to feed the media through. In addition, a central media line ends in a rotatable coupling. The weak point in this design is the seal. However, thanks to the use of high-quality rubber seals and sophisticated engineering, these pipes can withstand up to 1300 bar – at 300 revolutions per minute. This is made possible by the combination of different sealing technologies. Whether mechanical seals, hydrostatic seals or elastomer or “plastomer seals”. This enables us to respond explicitly to the requirements of our customers’ media, operating and process parameters. The most suitable sealing technology is used for each media channel. In special cases, all seals can also be combined in one housing if required.
Practical slip ring solutions for your application
Product catalogue for all slip rings
Find out about the different slip rings in our current overview. Transmission technology for complex industrial and safety-relevant applications form the core of our product range. All products can be individually adapted to the applications in order to offer you added value. Premium engineering - that is our claim for every single product we manufacture. We would like to convince you of this.
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