WaterCAD Help

[clemon]

To start off I am a recent grad trying to get some help. I am modeling a distribution system for a subdivision. I am trying to set up the point source for flow and pressure. I was reading the help menu and it says to use a reservoir and a pump. I am confused on how to do this. Any help would be appreciated.

Here is some info from the test sheet

FLOW TEST INFORMATION SHEET

Booster Pump 1 Static PSIG: 96 Residual PSIG: 84 Total Flow 2,925 GPM
Hydrant Elevation: 265

Tank Level: N/A Sterling Tank Level: N/A

 

[francesca]

Unfortunately the WaterCAD/SewerCAD manuals are rubbish, but if your support is current, even if it's the Bronze support, they'll get back to you within a day and their support guys are knowledgeable. You can also do instant message support if you catch them at the right time (they're in New England, so EST).

You don't have to use a reservoir and a pump, you can just use a tank. Seeing as how you actually have a pump and no tank in your scenario, however, just use a pump!

The tool to create the elements in your model is very straight forward and you can import a dxf background (export the water line from your CAD drawing) and that way you can have your pipe lengths work off your scale instead of inputting them. As for your pump, you need more than just the PSI, you need the pump curve. Hit up your local authority for it, or else you'll have to pretend that the pump is a tank of elevation that results in a Static pressure of 96 PSIG.

You should be working under a PE, and it's incumbent upon you to ask the PE to explain the hydraulics to you if you don't understand them.

 

[clemon]

I have the model all set up using the dxf. The only thing that i am struggling with is making the connection to the existing main with the fire test because thats all the information i have. As for the support with bently, are company's watercad is so old i doubt they have it(we have watercad 4.5) and our director doesn't want to upgrade. As for my PE explaining it to me i will probably have better luck with research on the internet.

 

[stanier]

Go and download Epanet 2 and use that . It is free, there is no support so you are no worse off than using Bentley and the tutorial is prettry good. There are a multitude of people out there who use it. Also it has no limits to the number of nodes and is free. It is the same engine as Watercad and othe proprietary software.

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au

 

[francesca]

If the PE doesn't care to make sure you're understanding what you do then you may as well make up the numbers and let him lose his license.

 

[DMcGrath]

I agree, the manuals are junk, and don't bother upgrading (high $$ and you don't even get a printed manual anymore, and predatory licensing policies). Ok, off my soap box....

A pump will need a source, and this can be designated as a reservoir or a tank. I usually use a reservoir as they don't go empty and you can maintain a constant static water level on the intake side of your pump. You will need the pump curve for sure, as francesca says. Remember that every node, tank, reservoir and pump in your system needs an elevation. Another thing you will need is a demand somewhere in your system. WaterCAD doesn't like pumps deadheading for no reason. Create a node that either has a demand on it or if you prefer an open pipe, set the emitter coefficient to something high, like 10,000 gpm/psi and it will flow like there is no tomorrow.

Bottom line with modeling (of any sort): Garbage in = garbage out.