Pumps

Pumps are links used to lift water to higher elevations. A pump curve describes the relation between a pump's flow rate and conditions at its inlet and outlet nodes. Four different types of pump curves are supported:

·       Type1: An off-line pump with a wet well where flow increases incrementally with available wet well volume

·       Type2: An in-line pump where flow increases incrementally with inlet node depth

·       Type3: An in-line pump where flow varies continuously with the head difference between the inlet and outlet nodes

·       Type4: A variable speed in-line pump where flow varies continuously with inlet node depth

 

Fig.49: Different types of Pump Curves (Source: User Manual for EPA-SWMM 5.1)

 

Ideal: An "ideal" transfer pump whose flow rate equals the inflow rate at its inlet node. No curve is required. The pump must be the only outflow link from its inlet node. Used mainly for preliminary design.

The on/off status of pumps can be controlled dynamically by specifying startup and shutoff water depths at the inlet node or through user-defined Control Rules. Rules can also be used to simulate variable speed drives that modulate pump flow.

The principal input parameters for a pump include:

·       Names of its inlet and outlet nodes

·       Name of its pump curve

·       Initial on/off status

·       Startup and shutoff depths