EPANET 1

[KLH Eng]

I have a very basic question about how to model flow and pressure data from a fire hydrant flow test in EPANET. I've seen several people say they model it as a reservoir and pump, but I'm unsure which flow test data to use to model it as a pump.

 

[hydrae]

How I would do it
Build the model without the fire flow, verify it matches normal operations.

At the node with the fire hydrant insert a flow equal to the desired flow and the system will calculate the pressure. Compare that to test data.

Hydrae

 

[GeoEnvGuy]

If you were to open a hydrant it would (spill all over the street) be modelled as going to an infinite reservoir at the elevation of the hydrant. If you connect a pumper truck it would (water down buildings on fire) be modelled as a pump at the elevation of the fire truck and an infinite reservoir at the elevation of the fireman holding the hose.

 

[Pinwards]

Typically you are not going to have the whole distribution system in your model, just a localized version in the vicinity of your project, so you use the Flow Test data to set the Pump Curve for the Reservoir/Pump that you use in the model to simulate the distribution system feeding your area. Flow test data should give you static pressure (at zero flow) that is 1 point on the pump curve, P residual at Q flowed for the test as 2nd point on the pump curve, and Calculated/Estimated Available flow usually at 20 psi residual as the 3rd point for the pump curve. That way the reservoir/pump in your localized model is reacting like the distribution system did in the flow test.

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