Valve recovery refers to the pressure recovery from the low pressure at vena contracta to the valve outlet. The term “valve recovery” is usually applied when a valve is employed as a restriction.
Valve Recovery Coefficient
It is a given that any valve could cause cavitation to a differing degree and in different closure positions.
If using a valve to cause a pressure drop as compared to control the flow of volume, it is safe to say that a low recovery valve will resist causing cavitation more than a high recovery type.
The valve recovery coefficient is a dimensionless, numerical factor that represents a valve’s flow vs. liquid pressure curve, and thus the valve’s tendency to cavitate. If this factor is higher than desired, cavitation might develop.
The valve coefficient is affected by the internal geometry of the valve, valve size, pressure, and the presence or absence of piping reducers adjacent to the valve.