Subject: How Does a TYPE3 Pump Work in SWMM 5?
A SWMM 5 Type3 pump flow is a function of the head difference between the downstream node head and the upstream node head (Figure 1) but the pump rules can be overwritten by a RTC Rule as in the attached example in which the pump is only turned on then the flow in the upstream link 8040 is greater than 25 cfs. Important components of the TYPE3 pump are: Surcharged Nodes to connect the Force Mains to the Pump (Figure 1), Force Mains (Figure 2), Wet Wells (Figure 3) and the TYPE three Pump Curve and the On and Off DEPTHs of the Pump (Figure 4).
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| Figure 1. Connect a Pump to a Force Main by Using a Surcharge Node Depth. |
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| Figure 2. Define a Force Main Link if you want to use either Hazen-Williams or Darcy-Weisbach for the Friction Loss in the Link. |
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| Figure 3. A Wet Well at the Upstream End of the Pump can have either a Functional Area or a Tabular Area versus Depth Curve. |
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| Figure 4 RTC Rules and Schematic of a TYPE3 Pump in SWMM 5 with Force Mains Added. |
