Calculating system curve with different pipe sizes 1

[Nutzman]

Good day all,
I'm sitting with a problem, in that I have a piping system in which the pipe system has different pipe diameters for different "parts" of the system. I have an 80mm line, branching off into a 25mm line, as well as a 32mm line. Both (branches)have different flow and head requirements. How do I "compile" then into a system curve?
All input will be welcome.

 

[Nutzman]

Hi LI,

Thanks for the headsup. I've used that product before, on a mining project with great success. Considering my product is clean water, could well do the trick.

 

[goutam_freelance]

In branched flow you need to calculate the individual branch flows iteratively, similar to being done in Hardy-Cross analysis. Since the flows are open ended, the pressure drop will be same (need to include static heads+ vel heads at outlets). The branch flows will change depending on individual branch resistances. After this calculate total flow Q=Q1+Q2. Del_P=KQ^2. Get K. Then draw the system resistance curve Del_P=KQ^2 at any flow with K remaining as calculated. Any throttling or addition of resistance in any branch will change the system resistance.