NES were able to assist in preventing a plant-stopping breakdown by giving early warning of a likely Head Pulley bearing failure in the Plant Feed conveyor.

Situation: The capable and experienced NES Consultant provided advice on the pulley bearing over a number of routine monitoring visits using trending and specifically targeted readings to track accurately the changes in values and frequencies indicating the damage.

Recommendations: The Consultant recommended the pulley be changed, purge lubrication of the bearings and close monitoring of the bearing condition until the change could take place.

Response: Site staff arranged the replacement by ensuring a spare pulley was on hand, the people and procedures were ready and the most suitable equipment was available for the day and time the change was planned to take place.

Follow-up: Following removal of the pulley and removal of the bearing, it was clear the outer raceway spalling and corrosion damage presented an elevated risk of failure of the bearing to the site. Various forms of evidence of bearing damage were found in our detailed analysis of the program data and our Consultant’s advice to purge the head pulley bearings with grease and replace the pulley at the next convenient opportunity was the right advice at the time.

Wrap-up: NES are new to this specific site and the previous condition monitoring service provider had not noted this bearing as having a problem but from the first set of readings we collected and analysed showed all was not well and serious damage was happening. Over the following few months the readings showed that it was deteriorating and the time for repair was approaching. Timely and detailed diagnosis of the problem provided the site with adequate time to plan for a safe and controlled repair preventing significant breakdown losses through interruption to production and consequential damage to adjoining conveyor equipment and structure.

Avoided downtime: estimated at 24 hours.