Research on the Flow Resistance Coefficient of a Multihole, Secondary Pressure-Reducing Sleeve Valve

When fluid flows through a regulating valve, static pressure changes due to the change of fluid area. If the static pressure is lower than saturated vapor pressure, cavitations erosion, and flash vaporization will occur. Cavitations and flash vaporization are the main causes of the vibration and noise of the valve. A multihole sleeve valve with a secondary pressure-reducing function is presented in this paper, two pressure-reducing components are assembled to the valve. The high-pressure difference in the valve can be broken down into several small pressure differences. But the pressure-reducing components have a significant influence on the flow resistance coefficient of the valve. So, the common flow resistance coefficient is no longer suitable for designing the multihole, secondary pressure-reducing sleeve valve. In this paper, the relationship of the flow rate, the flow area, and flow resistance coefficient of the valve is established. The flow area and the flow rate of the valve at the different openings are obtained using simulation software. They are substituted into the relationship equation, in this way, the flow resistance coefficients of the valve can be obtained. In order to verify the reliability of the simulation, a parallel flow test equipment for the valve is established, and the flow rate at different opening are detected. The test result shows that the valve designed by simulation conforms to the specified flow characteristics. By the revision of the flow resistance coefficient, the throttling holes of the valve can be designed conveniently and accurately. The designed valve has good flow regulating ability and can solve the problem of cavitations erosion and flash vaporization.