Worksheet 3
realized by M. Fraganza and M. Miccio rev. 1.3 of 13.04.2021
Objectives
Liquid data input
Select liquid:
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Input upstream pressure P1
Input downstream pressure P2
Input vapor pressure Pv
Valve data input
input Flow coefficient Cv
input Recovery Coefficient FL
The coefficient of the pressure ratio for liquids is:
YES / NO check for cavitation (IEC 60534 norm)
Calculation of the theoretical value that the recovery coefficient should have for the valve to enter into cavitation
(with the previous value assigned to ΔP )
Calculation and Plotting of the Flow Curve
Magnani, Ferretti e Rocco
The Incipient cavitation coefficient for a linear valve is
In the following, we use the same value above entered of the Flow coefficient Cv
Writing the salient point vectors, we give an asymptotic representation of the flow curve: