water modeling

[kingpawn]

I am modeling a water system for a subdivision and I need to set my tank elevation from the pressures I have from a fire flow test. My question is which pressure do I use and why? residual or staic?
Thanks for the help

 

[francesca]

You need to use the static pressure (no flow), then draw off all of the demands (including upstream), and make sure that you have at least the required residual pressure at the highest point along the line after you have taken off your subdivision load. You will also probably need to check with a fire flow in addition to normal loads.

If you cannot meet the required residual pressure you may have to increase the pipe size.

 

[RWF7437]

You FIRST need to check with the water supplier to determine if you must set your tank overflow elevation to match their existing tanks or their water system master plan. Then either do as they say or follow Francesca's suggestions.

good luck