Pneumatic Electric Control Systems (PECS) - Tech Tip: Correct installation of rotating unions
First Quarter 2008
Other technologies
Rotating unions are used to convey various media into and through rotating machine parts. Media such as water, hydraulic or thermal oil, compressed air, vacuum and coolants can be conveyed.
Installation examples for horizontally and vertically-mounted rotary unions
In the case of current rotating unions, sealing between the rotating element, the rotor, and the stationary part, the stator, is almost always achieved using suitable mechanical seals.
Despite extremely precise production and the use of highly wear-resistant materials, each rotating union is inevitably subject to wear.
Over and above the technical parameters which limit the service life of a rotating union, such as speed, pressure, temperature, flow, volumes and flow velocity of the media, other factors have considerable impact on service life.
Correct mounting is also an important factor influencing the service life of a rotating union. To prevent damage to the bearing it is important that the union can be easily rotated in mounted condition without any warping. Improper hose length or threaded parts may cause warping of the bearings.
The installation of the hoses is very important. The flexible hose should be attached to the rotating union and then connected to the shaft end and tightened to the prescribed torque. When connecting the flexible hose to the solid pipe, avoid twisting of the hose. Never connect the rotating union to a solid pipe. The hoses should be installed with a bow and without torsion and should be connected to the stationary pipe in a pressure-tight manner. The rotating union should also be connected to the machine part in a pressure-tight manner and at the torque prescribed by the manufacturer. It is important that the retainer for the rotating union is free from burrs or chips.
If required, the drainage must always be laid downwards (at least 15°) and with a free cross-section which is as large as possible. In the case of a rotating union installed vertically, the drainage must be guided downwards. For rotating unions which are mounted horizontally, the vent for controlled leakage must point downwards, in 6 o’clock position.
If the drainage is located higher than the vent, the rotating union will be flooded by the occurring leakage causing improper operation.
Listening to and observing a rotating union immediately after the initial operation quickly reveals incorrect installation. If it runs untrue or tumbles, the centring is not within the tolerance. This may be the result of wear of the screw thread or of a mounting failure. If the rotating union is noisy, vibrates or is hot in the area of the bearing it indicates that there is warping caused by the installation and that the rotating union is not running freely.
If these installation errors are avoided or are eliminated immediately the user benefits from an extended service life which is not reduced as a result of poor assembly.
This precision part operates highly effectively and helps to reduce machine downtime and maintenance costs in most cases.
For more information contact Pneumatic Electric Control Systems (PECS), +27 (0)31 303 3701, [email protected], www.pecspower.co.za
Further reading:
Next-generation motor management solution
Schneider Electric South Africa
News & events Other technologies
Schneider Electric has launched its TeSys Tera motor management solution in the West African market, combining advanced motor protection, digital connectivity and real-time diagnostics for manufacturing, mining and water applications.
Read more...
From concept to execution, unlocking renewable energy
Other technologies
Businesses already understand the benefits of renewable energy, however, as renewable energy solutions become more sophisticated, successful implementation requires a structured decision-making process that aligns technology choices with business objectives.
Read more...
Smarter, more secure electricity networks
Other technologies
As South Africa accelerates the rollout of smart prepaid electricity metering, innovative enclosure technology from PPS is helping utilities improve network security, reduce electricity theft and protect critical electrical infrastructure.
Read more...
Siemens launches SIMATIC AX WinCC Unified Elements
Pneumatic systems & components Other technologies
New engineering tool speeds automation application development, reducing the time required to bring industrial projects to market and empowering automation engineers to build, manage version control, and deploy visualisation engineering projects
Read more...
Decoupling software from hardware for future-proofed process automation
Schneider Electric South Africa
Other technologies
Legacy systems continue to perform admirably; the dilemma is that systems like PLCs, DCS (distributed control systems), SCADA and field devices were designed for deterministic, long-term operations.
Read more...
Duplex worm gears for precision backlash adjustment
Other technologies
KHK USA has introduced duplex worm gears that allow precise backlash adjustment through simple axial movement of the worm shaft, eliminating the need for gearbox housing alterations during assembly or maintenance.
Read more...
Corrosion solution for engine hot testing
Other technologies
Engine internals are at risk for corrosion from water used during hot engine testing and fill and flush activities. Corrosion affects the engine’s like-new appearance and threatens its integrity.
Read more...
Hygienic ultrasonic flow sensor
ifm - South Africa
Other technologies
The SU Puresonic Hygienic ultrasonic sensor from ifm detects flows of conductive and non-conductive media with high precision.
Read more...
Fault analysis for lifting equipment
Other technologies
Ensuring the sustained performance of capital equipment such as crane rails, ropes, hoist rails, gantry rails, and runway beams, which guide lifting equipment and support heavy loads, is essential for safety, reliability, and efficient operation.
Read more...
Bringing true mobile welding capability to SA agriculture
Other technologies
Bolt and Engineering Distributors has launched the new Fronius Ignis Battery. This is a next-generation, battery-powered welding system engineered for mobility, reliability and performance in off-grid agricultural environments.
Read more...
printer friendly version