Numerical study on cavitation in a globe control valve with different numbers of anti-cavitation trims

Cavitation is a destructive phenomenon in control valves. In order to delay cavitation, a multi-series of perforated cylindrical plates, called trims, are used. Previously, the effects of orifice diameter and different types of trims have been investigated. In this study, by numerical analysis, a globe control valve was investigated by employing four different cases (without trim, with one trim, with two and three trims) and the impact of the number of these trims on the intensity, formation region and the initiation point of cavitation was analyzed. It was found that the addition of one stage or two stages of trims reduces the intensity and delays the onset of cavitation, relative to the valve without trim. However, no significant differences in terms of intensity and initiation point of cavitation were observed in the cases where two or three trims were used. Therefore, due to the high cost of producing the trims, and the severe drop in flow coefficient, it is not economically and technically justified to increase the number of trims to more than three.