Most pumps are installed in pump stations with multiple pumps. However, for the purpose of hydraulic calculations, pumps need to be considered as individual elements and hydraulic data are assigned to pumps rather than pump stations.

The notion of pump stations changed significantly with the SELECT series 3 release of the Bentley storm and sanitary sewer models. Pump stations are treated differently in the GVF-convex solver vs. the implicit and explicit solvers.

Pump station elements are polygons and individual pumps are assigned to them by assigning the "Pump station" property for each pump element in the property grid. Pumps do not need to be assigned to pump stations for the model to run. Below, PMP-1 and PMP-2 are assigned to pump station PS-1 as indicated by the dashed line.

In the GVF-convex solver, it is possible to right click on a pump station polygon and analyze combination pump curves which can overlay pump head and efficiency curves and when the station is part of a runable model, can overlay the system head curve. See [combination pump curve help] for details.

Variable speed pump batteries can also be assigned to pump station but they are only used in the GVF-convex solver.

In the explicit and implicit solver, the pump station element is used only for drawing purposes and generally there is one pump element for each pump. (The ability to lump multiple pumps into a single station using Components > Pump station only exists in SELECTseries 1 and earlier. When importing an earlier model into a newer version, the pump station properties (initial level and on/off settings) are assigned to the individual pumps not a pump station.)

In special cases in explicit and implicit solvers, a Volume vs. Flow or Depth vs. Flow curve can be used to approximate multiple pumps turning on with a curve as shown below.