System-based Approach to Determine Design Factors in Fit-for-purpose Pumping Facilities

Pumping facilities are used to add energy to the fluid to transport certain flow rate from one point to another, between which gravity flow is not feasible. Designing pumping facilities involves several engineering disciplines, where each produce a direct impact in the pumping facility performance during its lifecycle. Therefore, they must be fully integrated throughout the entire process, and they have to define key variables to be monitored during the operation’s period to ensure that the design flow rate will be delivered. However, this is not always the case and many pumping systems fail at different moments of their useful lives. It has been seen that the engineering work and design are done separately by the disciplines abovementioned, sometimes without adequate integration of their work. The motivation for writing this paper comes from lessons learned over the last few years regarding the performance of pumping facilities designed and built in industrial facilities. This paper analyzes and proposes the use of a single ‘system-based design factor’ for pumping facilities composed by several pumps operating in parallel and pumps’ motors with direct start, to avoid oversizing and meet a fit-for-purpose design concept. A conceptual analysis is presented, where key variables involved are defined, and, based on a real pumping facility, a model is built using a commercial software for performing a sensitivity analysis. Given the results of the sensitivity analysis, the ‘system-based design factor’ then can be distributed in different components of the pumping facility according to their inherent risk or impact.