Reducing Reliability Incidents And Improving Meantime Between Repair

Lecturepg. 1Recently much attention is being given to the total cost of pump ownership. In many cases, for process plants, the cost of unscheduled maintenance can become critical since these costs can impact production runs and result in significant environmental cleanup. The cost of unexpected downtime and lost production can rival energy costs and the cost of replacement parts in its impact (Hydraulic Institute, 2001). The loss may be thousands of dollars per hour and can dwarf all other elements of life cycle cost. A study was proposed to help a major user achieve its goal of reducing vibration levels for rotating pump equipment in order to reduce reliability incidents and improve mean time between repair. A test program was subsequently conducted to investigate the influence of certain pump hydraulic factors and to determine the effects of speed, impeller diameter, and operating point on vibration reduction and reliability improvements. This paper quantifies the benefits of lower speed operation on vibration reduction as compared to traditional operation at synchronous speed. It also builds on and expands the investigation into the effects of speed, operating point and impeller diameter on centrifugal pump reliability previously undertaken by Bloch and Geitner (1994), Erickson, et al. (2000), and Budris, et al. (2000)