Flowrate

[notsocivil]

Hello all,

Please help I am struggling with a water distribution model that says I am okay with kypipe but when I do it by hand I am not sure how it will work. I basically have a parallel pipe system (a six inch that splits into a 6" and an 8") I know the flowrate and pressure (670gpm) 'upstream' before they split so I calculate the flow in each branch and come up with about 436gpm in my 8" branch after losses with about 44psi. If I tap into the 8-inch will I ever get 500+gpm if its flowing 436gpm now or is it a matter of the demand and the pump, tank upstream? Thanks.

 

[monaco8774]

I dont know if this answers your question but you have to do an iterative calculation at the branch. The pressure drop through each branch is identical if they either rejoin or they exit to the same pressure. What you do is guess flow in 6" branch this gives you the flow in 8" (total flow 670 gpm - guessed flow) then calculate pressure drop in each, if the 6" comes out higher than the 8" reduce flow in 6" and recalculate again. you can always solve this as a matrix but it would take a while to explain so trial and error is good enough. When the pressure drops match that is the correct flows and the correct upstream pressure.

 

[BigInch]

You can get up to 670 gpm in either branch if you can lower the outlet pressure in that branch enough to do it and at the same time raise the pressure in the other branch enough to do it.

http://virtualpipeline.spaces.msn.com