Most pumps used in water and wastewater systems are equipped with check valves to preclude reverse flow and/or nonreverse or ratchet mechanisms that prevent the pump impeller from reversing its spin direction. This usually restricts the pump’s operation to the first quadrant. Provided such a pump will operate continuously at constant speed throughout the numerical simulation and never allow reverse flow or spin, a standard multipoint pump curve provides a rigorous and sufficient representation. The Constant Speed - Pump Curve under Pump Type (Transient) enables you to represent this pump configuration during a transient analysis.

If you have the multipoint pump curve, you can enter it directly in HAMMER CONNECT or import it from another model or datasource. The pump curve is used by HAMMER CONNECT to adjust the flow produced by the pump in response to changing system heads at its suction and discharge flanges throughout the simulation period.

If a pump curve is not available, but you can obtain the rated head and flow from the SCADA system or other measurements, enter these as the Nominal Flow and Nominal Head, and select the four-quadrant curves whose Specific Speed is closest to your pump: centrifugal, axial-flow (single and double-suction) and multistage (including vertical turbines), as shown in “Table 4-3: Specific Speeds for Typical Pump Categories in both Unit Systems”, then select the Constant Speed - No Pump Curve option under Pump Type (Transient). You can also use one of these in-built four-quadrant characteristic curves if reverse flow or spin is possible, but you do not have these data for your pump. This will yield a physically meaningful answer, even if the parameters are inexact. The four quadrant characteristics curves are used for all pump types except Constant Speed - Pump Curve.