Design of cages in globe valve

Abstract

A globe valve is a common device that performs flow control in a pipe system. The flow capability of the globe valve is estimated by a flow coefficient. To improve the control capability of the globe valve, a cage is utilized to adjust the flow coefficient in the valve. For example, if one feels like decreasing the flow coefficient, then a cage with numerous passageways will be considered rather than replacing a smaller valve and pipe. A double cages design is also employed to reach the same purpose. The flow coefficient of the valve is associated with passageways in the cage. Provided that the relationship between the total cross-sectional area of passageways and the flow coefficient is known, then one will be able to design another cage with required and re-allocated passageways to control the variation of flow coefficient. The objective of this study is to use computational fluid dynamic technique to predict the relationship. Furthermore, one can change variation of flow coefficient in a globe valve using a new designed cage with re-allocated passageways. Again, the change of the cage on the flow coefficient can be validated by computational fluid dynamics again. This approach would be useful for a valve engineer to design a cage to control the flow capability in a globe valve.