Case Studies

Original Equipment Manufacturer: Design modification

An OEM realised that under certain circumstances it was possible for their control system to allow a small pump to run dry for about 1 hour before being detected as a system failure. We were required to provide a seal that could run dry for up to 1.5 hours and still provide effective sealing once the original system failure was detected and rectified. After extensive testing a solution was found by changing the contact surface area of one of the faces. Our timely modification was a key factor in significant reductions in warranty claims.

Trouble shooting on the pump production line:

An OEM was experieincing unacceptable levels of leaking pumps at the end of the production line. Procedures and all key components were closely scrutinised. It was found that some plastic components were out of tolerance and that improvements needed to be made to the way seal elements were being fitted. Prototype fitting tools were provided by our company. Our customer attended to all matters of concern and the issue was completely resolved.

Onsite trouble shooting:

Significant potential problems were arising from leakage of a volatile liquid from transfer pumps. Seals were being replaced every 2 to 10 weeks at significant cost under warranty. Pump downtime and safety issues were of major concern. We presented on site with the maintenance subcontractor to get a complete overview of the situation and analyse the condition of all parts in the pump assembly.

The preferred elastomer options showed minor and relatively insignificant differences in performance. Additional shaft support bearings were indicated and immediately installed. These provided major improvements to seal operating conditions. Changes were also made to the bearing maintenance program. This created a dramatic change to the sealing environment with complex interactions between the sealing assembly and the bearing assembly. The failure sequence was determined to be bearing seal failure followed by bearing failure and then complete seal failure.

Recommendations were made for changes to the type of bearing grease. All factors contributing to poor seal performance were rectified. Seal life has been extended to beyond 4 years with the pumping system now considered reliable and efficient.