Reusing reconditioned bearings

Sam was visiting a pulp mill during an annual outage as part of his responsibility to provide advice for improving maintenance and reliability practices.

This mill had a well-planned outage and a good record of meeting each outages’ goals, e.g., minimal duration and optimal costs.

He generally asked a lot of questions, attended outage status meetings, visited operating areas during this visit.

On a walking route he came upon several 55 gallon drums filled with roller bearings, some looking almost new. A couple, that he could reach and observe, had the appearance of damage, whether from use or removal, though, was difficult to judge.

Asking a colleague whether he has seen these bearings, obviously being thrown away, stated that he ‘had not, only because his assignment was to help with removal and installation of some specific difficult and critical bearings during the outage’.

Sam continued to ask questions of the people familiar with the area, namely the mechanics and operators.

He gathered from those discussions that the outage plan including automatically replacing all the bearings on this series of duplicate assets every annual outage based upon OEM recommendations and past practice. A PM in other words.

Sam had some reservations about the practice of replacing all the bearings periodically now that vibration monitoring had established itself as a credible practice of its own compared to maintenance practices when the mill had been built, Sam was questioning the disposal of obvious good, albeit TBD, bearings.

He knew that reconditioning bearings was still not a universally accepted practice with the industry, mainly due to some very poor performance results from the workmanship by ‘questionable’ reconditioning shops, but he also knew that when done correctly the reconditioned bearings performed well and at less cost than a new bearing, not to mention the benefit of recycling in general, a practice well established in the paper industry.

Before leaving the site, he prepared a cost/benefit analysis for those specific bearings over the life cycle of the assets, some twenty years, assuming that 80% of the replaced bearings could be reconditioned and placed back in stores for the next outage.

Sam discussed this with his company’s site manager, who would ultimately bring the matter to the attention of the site’s management.

Sam also suggested the mill maintenance and reliability folks establish a KPI using periodic (annual, quarterly) bearing cost per tonne as a lagging indicator of leading processes such as lubrication and condition monitoring, including basic care.

Also discussed was to have a technical applications engineer from their bearing supplier on hand during their annual outages to advise, oversee and make decisions about applications, conditions and installation techniques. As much a training opportunity as a ‘service’ visit.

Sam knew, from experience, that changing a culture to adapting new practices was a difficult task in an established mill operations, so a process had to be developed to support the change, in this case saving the bearings, taking care that they were not damaged during dismounting and handling while waiting for examination by qualified people, usually the technical applications specialist of the bearing manufacturer or their authorized distributor.

Yes, they would still be changing out the bearings on an annual basis, although Sam thought this too would eventually be reconsidered as a requirement, or a best practice, once failure modes were identified for those bearings that were failing within the year of service and mitigation actions enacted.

Still, the cost benefit of reusing reconditioned bearings was a worthwhile effort, not to mention the continuous improvement concept being implanted and reinforced within the culture’s mindset, especially when widely broadcasting the benefits, and honoring the participants.

The lesson learned is simple, just because it has been done this way before does not mean it is the best possible practice.