Experimental Research on the Cavitation Suppression in the Water Hydraulic Throttle Valve

Abstract

A water hydraulic throttle valve is often used to control the water flow in piping systems. When the water flows through the valve port, cavitation occurs frequently because of the high pressure drop across the valve. The cavitation can lead to wear, vibration and noise. To solve the problem, a modified throttle valve with a drainage device is proposed to suppress the cavitation. A contrasting test was conducted to analyze the effect of drainage device on the cavitation suppression. For evaluating the influence of inlet pressure and outlet pressure on the ability of the drainage device to suppress cavitation, the power spectrum density (PSD), normalized intensity, and cavitation suppression coefficient (CSC) of dynamic pressure are introduced. The results indicate that adopting the drainage device is a feasible method to suppress cavitation. In addition, the inlet pressure and outlet pressure have a great influence on the capacity for cavitation suppression of the drainage device (CCSDD) by changing the intensity of cavitation. When the inlet pressure is at 4.0 MPa, the cavitation is generated and the CCSDD is weak. With increasing inlet pressure, the intensity of cavitation and CCSDD is gradually enhanced. But when the inlet pressure increases to 7.0 MPa, the cavitation is saturated and the cavitation suppression by the drainage device begins to decrease. On the other hand, the effect of cavitation suppression decreases significantly when the outlet pressure increases from 1.4 MPa to 3.8 MPa.