Thanks Latexman!
I have calculate the friction loss of the fluid (viscosity=0.2cst) for pipeline, it was 6% lower than fluid with 1cst. I suspect a similar thing may happen to a control valve, which mean lower pressure drop for low viscosity (higher CV).
What do you think?
I am using the CV curve from control valve vendor to calculate the liquid flowrate, I found the actual flowrate is higher than predicted.
I know the CV value of control valve was generated with water, for viscosity fluid, a factor should be used for correction, and actual CV will less than...
I know that high viscosity fluid will make the DH of pump decreased, and I did found the correction methodology in reference book. In the other hand, I think the lower viscosity (than water) may make the DH of centrifugal pump increased. Let said a fluid with 0.2Cp viscosity may have a 5% high...
Most of engineer told me that the pressure of cooling water return pressure should not be too low (generally higher than 1BarG).I believe it is correct, but I don't know why, can anyone tell me.
