In cases where shop rotor balancing is not possible due to operational constraints, field balancing is considered as the optimum option. This has advantages as it takes account of direct operational requirements such as: nominal rotational speed, reduction in turnaround of the machine, etc.
Understanding that imbalance is the most common cause of high vibrations, Rotofix Solutions utilizes portable Schenck equipment to perform field balancing (in-situ balancing) that allows non-removal of the rotor, thus reducing time allocated to repair and operational costs.
As a normal practice, our experts perform a preliminary spectral vibration analysis of the unit in question to identify the real causes of the vibration problem, discerning from a large array of defects that can be easily (but incorrectly) diagnosed as rotor imbalance (e.g. increased bearing clearances, bent shaft, shaft misalignment, cracked shaft, soft-foot, etc.).
Our team then proposes a clear execution plan taking into account:
- The number of stops / starts needed to accommodate the unit starting cycle limitation in order to achieve successful field balancing.
- Work safety requirements for corrections weights placing activities, etc.,
- Issues that require advanced discussion and agreement with the facility maintenance team.
In the main, our team conforms to ISO 21940-11:2016 “Mechanical vibration – Rotor balancing – Part 11: Procedures and tolerances for rotors with rigid behavior”, but we can adapt to any situation.
Upon completion and acceptance, Rotofix Solutions will comprehensively document the field balancing parameters stating the quality of field balancing, not only for maintenance history, but also for simplifying future maintenance works.