FAST, safe and versatile FAG medium frequency induction heating technology has demonstrated its value in service with one of the world’s leading subsea engineering and construction companies in the oil and gas sector, Subsea 7.

The FAG induction technology – being introduced to Australia and New Zealand by Schaeffler Australia – was used to reduce the complexity, cost and in-port time to repair a major reel bearing on one of Subsea 7’s largest vessels, the Seven Navica.

The 108.5m Seven Navica is a pipe layer ship within the busy worldwide fleet of Subsea 7, which has annual revenues exceeding $2 billion and a global network of operations including Australia.

FAG units’ focussed heat induction and high energy density allow fast heating and particularly safe, energy-efficient performance to facilitate key bearing installation and maintenance tasks across diverse industrial applications (including oil and gas, mining and energy, mobile and static manufacturing and process engineering machinery installation and maintenance, maritime exploration and engineering, and safety).

“The customer had to replace the existing starboard reel bearing, in which a static fault was highlighted during a condition monitoring test, said Schaeffler Australia Industrial Services manager Mr Mark Ciechanowicz.

“Based on the test result, Subsea 7 elected to change the bearing, which also gave the opportunity to examine the condition of the journal, in particular its outside diameter.

The FAG medium frequency induction heating system is a simple operation.

The FAG medium frequency induction heating system is a simple operation.

The challenge in this operation was to minimise the time the vessel was in port, thereby reducing pipelay downtime for Subsea 7,” he said.

Schaeffler solution

Specialised Schaeffler fitters equipped with FAG tools for bearing mounting and dismounting supported Subsea 7 during the installation work at the Dusavik fitting yard in Norway. The bearing was heated with a FAG medium-frequency device equipped with flexible inductors. Schaeffler expert staff were on-hand to offer advice and help in the event of any difficulties experienced with the reel bearing change.

Bespoke mounting and dismounting tools were used to ensure accuracy and safety of the re-build. Condition monitoring measurements were conducted to guarantee the operational integrity of the replacement bearing, a special spherical roller bearing, 240/1120 series.

Condition monitoring – a service in which Schaeffler is a worldwide authority – ensured that a baseline condition for the replacement bearing could be established.

Customer benefits

In using the specialist skills available from Schaeffler, Subsea 7 benefitted from the broad bearing and service knowledge of a leading global bearing manufacturer. This guaranteed that the fitting procedure was carried out efficiently and with a high degree of accuracy.

Reliability was further safeguarded by using FAG Arcanol LOAD 220 grease in new bearings and for relubrication.

By using the heating method selected, the complete mounting time was reduced by one day – equivalent to daily stoppage costs of the vessel of €110,000 (about $A170,000).

The customer also realiSed further cost savings by using medium-frequency heating of approximately €8 000 ($A12,000) in comparison with other methods (which involve further expenditure, such as costs for setting up an oil bath or resources for gas flame heating (four people, each working three  hours).

What’s special

The medium-frequency heater with flexible inductors allows the heating of large bearings or large and difficult-to-access mating parts in a very safe manner. The significant feature of inductive heating in comparison to other heating methods is that the heat is produced directly in the workpiece. This results in significantly shorter heating times and lower energy consumption.

As a result of this successful cooperation, Subsea 7 has elected Schaeffler as its preferred supplier for bearing products and services for the future.

The latest FAG medium frequency induction units from Schaeffler Australia deliver rapid, simple and safe heating performance to facilitate key bearing installation and maintenance tasks across diverse industries.

The versatile devices facilitate, in one unit, the mounting and dismounting of medium to large size rolling bearings and other ring-shaped steel parts, such as machine carriers and housings, reducing the amount of mounting work and cost in single and batch operations.

The units operate over a frequency from 10 Hz to 25Hz, attaining a generator efficiency higher than 90%t. Functioning almost silently, they achieve lower mains connection power than heating devices with mains frequency and deliver environmentally compatible operation, with no oil involved in the process.

FAG medium frequency induction heaters are ideal for applications across a wide diversity of industry, inside or outside, including mining and energy, oil and gas processing, heavy road and rail transport, materials handling including port loader facilities, manufacturing and steel, primary product and food and beverage processing, pulp, paper, packaging and forestry, and major infrastructure and water and waste recycling plant.

Specific applications include:

  • Customised solutions according to the sizes of the bearings and parts to be heated for mounting and dismounting, Flexible or fixed inductors so it can be tailored to individual company requirements and
  • Batch dismounting of bearing inner rings and labyrinth rings (eg, axle box bearings in all rail vehicles, as well as dismounting of bearing inner rings from all rail vehicle traction motors)
  • Heating of large machine elements, such as bearings or bearings seats in a machine carrier (eg, in wind turbines)
  • Heating of rolling rings and couplings (eg, in steelworks)
  • Loosening of shrink fit connections.
  • Control of heating according to time and temperature. Automatic demagnetisation.

Extremely versatile

The flexible inductors are attached directly to the part to be heated. If several similar parts have to be heated, the inductors can also be fixed to a frame. This saves time and costs, says Mr Ciechanowicz.

The compact air-cooled device comprises two parts: an inductor and a generator. The inductor can be of flexible design or fixed design. The fixed design is particularly suitable for batch applications.

The flexible design inductor can be wound around components. It can also be used with subframes to rationalise repetitive work.

Overall, this gives a wide range of applications.

Because of their compact construction, the devices are easy to transport for use anywhere. The FAG medium frequency heating device is much smaller, lighter and consumes much less energy than equipment used with conventional methods. Their portability is a benefit where they are needed at infrastructure and electricity facility construction sites, for example, for turbines or other large components that are difficult to transport.

The Schaeffler Group also offers a bearing induction heating service, including mounting support.