Ray Hardee is a principal founder of Engineered Software, creators of PIPE-FLO and PUMP-FLO software. At Engineered Software, he helped develop two training courses and teaches these courses internationally. He may be reached at email@example.com.
Lastly, it is common in dewatering situations to have multiple sumps feed into a common header, so the interaction of multiple pumps is something that must be considered. In our simple model, the addition of the East Pump has only a small negative effect on the performance of the West Pump, pushing the operating point away from the BEP.
In systems with multiple sumps, wellpoints or deep wells, multiple-source elevations and pumping into common headers can have significant effects, including reversing flows and causing pump damage as various pumps are brought on- and offline.
A full system analysis looking at different scenarios will lead the engineer to a greater understanding of the interactions between the pump elements, determine the most critical areas within the process elements, and find the most efficient locations and controls to operate the system in all situations.
As discussed, even a simple dewatering system has all the elements of more complex piping systems—pump elements, process elements and control elements—as well as all the same problems large systems experience.
Taking steps to mitigate these problems, even simple steps such as extending discharge piping or adding a well-placed manual valve, can have a positive effect on uptime and operating costs.