Abstract: Aiming at the problem of valve core clamping in valve engineering application, taking the example of valve core clamping in recent years as an introduction, the causes of valve core clamping were analyzed and summarized, and the formation mechanism of valve element sticking was comprehensively and deeply understood.The causes of valve core clamping could be divided into: mechanical reasons caused by machining accuracy or assembly errors, hydraulic reasons caused by the unbalanced torque of the fluid acting on the valve core, thermal reasons caused by fluid viscosity and heating under high-pressure conditions, and the pollution reasons caused by particles staying in the matching clearance of the valve. The experimental measurement methods, theoretical model analysis methods, multifield coupling analysis methods, and preventive measures for valve core clamping such as diagnostic detection and valve structure improvement were summarized.According to the content of the review, some problems to be solved in the future are summarized and pointed out: the research on the clamping problem of valve core considering various factors; study on preventing particles from entering the fit gap between valve core and valve body; comparison of the effects of fluid, machinery and particle pollution on clamping; methods for preventing valve core from clamping in addition to the adjustment of pressure equalizing groove and valve core-valve body fit clearance, etc.
Key words:  valve; causes of valve core clamping; thermal deformation; particle contamination;pressure equalizing groove; fit clearance of valve core and body; preventive measures