graphing pumps in parallel
graphing pumps in parallel
(OP)
I've a spreadsheet for plotting pump curves on one chart but the problem is in adding the abscissa (x, flow) values for the same ordinate (y, head) values. The two curves are not input with common y-values. The fastest way seems to be to plot out the two pump curves on one chart then create the combined curve manually by hand with a ruler. Presentation isn't the best. Pump supplier software is geared for their pumps alone and I want to be able to superimpose a couple different mfgr's pump curves on my system curves. Any ideas?





RE: graphing pumps in parallel
>Edit >paste special > paste as new series, columns, categories in first column, make sure replace existing categories is not ticked. >OK
Viola
Cheers
Greg Locock
RE: graphing pumps in parallel
RE: graphing pumps in parallel
What you'll need to do is to use the MATCH function to find the closest value and then algorithmically calculate the interpolated value for the sum. MATCH returns the position of the number that's smaller, larger or equal to the lookup value. You can then use the OFFSET function to generate the interpolation.
TTFN
RE: graphing pumps in parallel
Cheers
Greg Locock
RE: graphing pumps in parallel
May I get a copy when you get it working??
Thanks!
Keep the wheels on the ground
Bob
showshine@aol.com
RE: graphing pumps in parallel
it will be helpful for me as im fresh graduate
Best regards:
gladiator_me@hotmail.com
ansari1
RE: graphing pumps in parallel
If you have pumps in series make the flow a fixed
number and input the corresponding head units.
Alternatively, you can create an approximate pump curve using the equation H = A + BQ^2. In excel use linear regression simply by taking your Q-H data and squaring the Q. Perform the regression on the Q^2 vs H and the A, B coefficients will then fit the above equation. Substitute your H and then solve for Q.
For equal size pumps in parallel, simply multiply the flow times the number of pumps and plot.
RE: graphing pumps in parallel
In Excel you'll need to select the XY Scatter plot, then connect the data-points. I had the same problem building the my graph. I use 10 data points from selected pump(s) to plot the combined pump curve and then plot my calculated system curve.
Don Coffman
RE: graphing pumps in parallel
No more things should be presumed to exist than are absolutely necessary - William of Occam