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Lobe Pump Repair – Case Study

In a Nutshell


  • Chemical


  • Lobe Pump


  • Repetitive failures due to mechanical seal damage
  • MTBF < 5 months


  • Analysis of root cause failure
  • Pump modification – installation of pressure relief system


  • CPM’s Pump Test complete
  • Cost Savings: approx. £12,000/year
  • Downtime Savings: approx. 30 days/year

CPM recently assisted a client in the Chemical industry with repetitive failures with a lobe pump.

The pump was failing every few months due to mechanical seal damage. CPM worked alongside the client to understand the application and the route cause of the failure.

Testing is a critical aspect of the repair and refurbishment programme. Initial testing can be performed in order to replicate the customers reported fault, it can determine the Root Cause Failure and its efficiency can be measured and compared to that of the Original Equipment Manufacturers (OEM) test certificate.

It was found due to the setup of the application, there was a build-up of pressure in the system due to several pumps working in parallel. After analysing the setup and the failures, it was found that the during switch over of the pumps there was a pressure build up which caused the pump to fail.

CPM then agreed with the client to modify the pump to install a pressure relief system in it that would help in preventing the seal failure. This achieved customer’s requirements for cost savings by extending the MTBR and reducing maintenance intervention, as well as the energy reduction that the pump consumes. It also reinforces the confidence that the repair has been tested, is operating safely and meets production needs for reliability and performance.