Damping Effect and Fluid Dynamic Analysis on Closing Process of Axial Flow Check Valve

Axial flow check valve (AFCV) is widely used in piping systems because of its small flow resistance, low noise, and good sealing performance. Its working performance directly affects the safety of the pump unit and the reliability of piping system. In the event that an accident occurs in piping systems, AFCV is closed to prevent backflow. However, rapid closing of the valve can cause the disk to exert a large impact load on the seat, which can affect the service life of the valve and the process safety of the system loop. Therefore, it is necessary to study the transient closing characteristics of AFCV with damping structure. The dynamic mesh technology is used to simulate the closing process of AFCV with different damping structures. The effects of the structures of damping devices as well as the diameter of damping holes on the dynamic motion, fluid force, and damping characteristics are analyzed, respectively. The results show that the damping structure with damping holes not only has better performance in slow closing and deceleration than the damping structure with annular gap but also reduces pressure fluctuation more effectively. Moreover, the fluid damping force generated by the damping structure with damping holes during the closing process is linear with the square of the velocity. Also, the correlation between impact velocity and the diameter of damping holes is obtained. The selection strategy of machining accuracy of damping holes is proposed. This work can provide a certain reference value for the design of AFCV in practical engineering, and it can also benefit safety and maintenance of piping system.