Venturi Flow range

[PUMPTESTER]

I have a venturi test report that has data from around 1.5 Million to 3.5 Million pipe Reynolds number which corresponds to about 7000 GPM to 18,000 GPM per the test report. At the bottom of the report there is a statement “For a pipe Rey. # Above 1.5 x 10^6 the avg. Coef = .9872 with a standard Deviation = .0007”

Question: Does the venturi have an upper flow range? I guess another way to ask it is once the lower range is calculated through testing is the resulting constant linear through all higher flows beyond the tested range? I have contacted the testing facility but they have not responded so I thought I would try here.

 

[dcasto]

There is no upper limit. The lab report says that you can used a fixed coef and only have a +/-.0007 (units)over 65% of the range. There is a correction factor for reynolds number that you can use over a wider range. See Miller and Spinks.