WaterCad Model - Point of Connection

[CrimsonEngineer]

Its been a while since using waterCAD and I am looking for help on how to model the connection from the existing system to a proposed system extension.

I have been given the following information from the City based on their hydraulic model of the sytem.

Elevation of Connection: 732-ft
Hydraulic Grade at Connection: 891-ft
Static Pressure: 63 psi
Available flow: 2,120 gpm at 20 psi.

What is the simplest way to model the connection? It seems that if I use a reservoir only that does not take into account the available flow. If I use a reservoir and pump I am not sure on how to get the three data sets for a pump curve.

Any help is appreciated!!

 

[coloeng]

I would ask the City for a fire flow test. This should provide you with the three points needed for a pump curve.

 

[Lan123]

To be conservative, why not have a reservior with floor El = 723 and a water surface at 723 + 20*2.31 and a Flow control valve with a setting of 2,120 gpm downstream of the reservior.

What is your average, peak and maximum demands? What is the minimum residual pressues requirement for your pipeline ? 20 psi/

 

[cvg]

you could just draw a straight line between static and residual which should be a conservative estimate. you will eventually need the fireflow test

 

[CrimsonEngineer]

Thanks All, My demand that I need to meet is 1500 gpm at a minimum of 20 psi.

For now I have set up a model using a reservoir at an elevation of 732 and a pump with three data points. I followed cvg's advice and drew a straight line between my known static and 20 psi residual readings to approximate my third point.