Pump Design -Help 1

[niibii]

I am trying to design a small pump for a set of condos (3-storey. I have been given the flow test on the water system in the area. Residual- 35psi, Static - 55psi pitot of 1500gpm. I mean there is alot of water in the area but the pressures are just not enough to meet 20psi for 1000gpm for fire flows. There is a total of 50 units.

Could anyone help with sizing the pump. I did the waterCAD analysis for the development but was having negative pressures at a fire hydrant I placed in the development.

Thanks

 

[francesca]

Get a set of candidate pump curves and put a pump into your WaterCAD model. When you find one that works correctly, take it to someone with experience to check your model and calculations.

 

[redbridge]

I may not be understanding you correctly but did you say there was a residual pressure of 35 psi @ 1,500 gpm flow. That is more than 1,000 gpm @ 20 psi.

 

[BigInch]

That pump won't work there.

http://virtualpipeline.spaces.msn.com

 

[cvg]

before you get too carried away, try and get another fireflow test and do it closer to your site. It's not unusual to see variations from one test to another and you may be surprised to find out you have more pressure than you thought. Then try bumping up the size of your fire line connection to the watermain. Use at least 8 inch and if it is a very long run, try 10.