Case Study by: Denver Osthoff, Armstrong World Industries


Bearing failure can lead to unplanned downtime and production interruption.  This can be extremely costly and impact the company’s bottom line.  Allowing bearings to run to failure was not an option.  Relying on older mechanics to intuit a potential failure was not feasible either.  Looking for cost-effective, reliable technologies to improve equipment availability and reduce maintenance costs was the option.


The company started out with an Ultraprobe 9000 as part of a corporate initiative to enhance PdM technologies.  They eventually upgraded to the Ultraprobe 10,000.  They started the program slowly to gain an understanding of the technology and improve their proficiency with it.  Denver first started off calling UE Systems for help and eventually attended a Level I class. They currently have 3 Level I technicians in the plant. He and the maintenance department gradually built up a trust in the data and in the instrument and began a full time inspection program to monitor bearings.


In one instance an outboard bearing on a 200 hp motor was identified as in a failure stage and scheduled for replacement.  The replacement cost was $1287.  It was estimated that had there been a catastrophic failure the cost of the new motor plus labor plus a crane and the downtime in the plant would have been $78,075.  The net savings were: $76,787.00.

In another instance a bearing on a pump was identified as in a failure stage and trended until it was decided to replace the bearing.  The cost of the replacement was $1707.  Had the pump run to catastrophic failure, the cost of a new shaft, bearings, labor and plant downtime were estimated at $86,902.00 for a net savings of $85,195.00!

For two years since the implementation they have not experienced a catastrophic failure.  As a result of their success 5 additional plants in the US now incorporate ultrasound in their PdM program.