Site operations and preventive maintenance


Vibration measurements 

  • A vibration analysis is an important part of preventive maintenance. It provides information on future bearing failures and helps avoid unscheduled shutdowns.
  • Route measurement of fans and motors will take place using a Pruftechnik VIBXpert II vibration analyser. Data is gathered using an acceleration sensor at each bearing from three directions (vertical, horizontal and axial). The route measurement produces overall vibration values, velocity and acceleration spectra, and an envelope measurement in the frequency range of 0.5–40 KHz.
  • We then work with the customer to draw up an action plan based on the measurements and analysis to improve the availability and safety of the system. 

Balance checks and balancing 

  • Balancing of fan impellers is carried out based on observed imbalance or a vibration analysis. The purpose of the balancing process is to achieve rotor balance to minimise vibration that will cause bearing failures and fatigue fractures.
  • The rotating components of the fan will undergo balancing using a Pruftechnik VIBXpert II device. Balancing may be performed as a static or dynamic process to achieve the best possible outcome.
  • We can use portable equipment to perform balance checks and balancing at customer facilities anywhere in the world. 

Axial alignment 

  • Axial alignment ensures the proper alignment of the fan and motor shafts in radial and axial directions. Axial alignment must always be checked before a fan is started for the first time, and in each maintenance outage.
  • An unaligned device will increase the bearing load and cause vibration that may lead to equipment failures.
  • Axial alignment is carried out using an Optalign smart RS device and alignment plates. Three alignment options are available: multipoint, sweep or three-point measurement. Before actual alignment, soft foot check is always carried out.
  • We can use portable equipment to perform axial alignment at customer facilities anywhere in the world. 

NDT inspections

  • An NDT inspection will reveal early fractions and weld cracks that may in a worst case scenario lead to a sudden failure of the fan.
  • A qualified specialist performs the NDT inspection as a visual inspection or using a liquid penetrant or magnetic particles. An ultrasound examination may also be performed.
  • Inspections are carried out 1–2 times per year or during a maintenance outage, depending on the process.


  • Professional fan commissioning will confirm the appropriate quality of the installation work and the fulfilment of requirements before continuous process operation begins. Failure to fill a commissioning record will lead to the rejection of any guarantee claims.
  • Commissioning takes place after an installation check has been performed, and before continuous operation of the fan begins.
  • Commissioning is always performed at the first start-up of the fan and after the replacement of a main component such as the impeller, bearings or motor.

Installation inspections and supervision

  • A mechanical installation inspection improves the long-term availability of the system and helps avoid unscheduled fan shutdowns. The purpose of the inspection is to ensure that the fans have been correctly installed in accordance with the manufacturer's instructions, drawings and standards.
  • The inspection also aims to verify the mechanical condition of the fans and to identify potential risks. A professional installation inspection ensures the continuous safe operation of the fan and helps predict future maintenance and spare part needs.
  • Inspection of the mechanical condition of the installation must be performed annually.
  • Our experienced project managers will ensure smooth coordination of the project between all participants.