Internal flow and vibration characteristics of axial flow check valves based on fluid-structure interaction analysis

Axial flow check valves are primarily employed to regulate the unidirectional flow of fluids within pipelines, preventing backflow or reverse flow. The design of this type of check valve ensures its opening in the direction of fluid flow and closing in the case of reverse flow, thereby ensuring that fluid within the pipeline system can only move in the predetermined direction. This paper establishes a three-dimensional physical model of the axial flow check valve with the length of 2050 mm, the height of 2200 mm and the inlet/outlet diameter of 1716 mm. Dynamic characteristics of the flow field during the closing process of axial flow check valve under different pressure difference were studied using dynamic mesh technology and User Defined Function. The vibration of the valve stem of the axial flow check valve was predicted and analyzed through fluid-structure coupling. Additionally, a fluid-structure coupled approach is employed to predict and analyze the vibration of the valve stem in axial flow check valves. The results indicate that with an increase in the pressure difference at the inlet and outlet, the time required for the check valve to close decreases, leading to an acceleration in the valve disc’s velocity. Simultaneously, the fluid forces exerted by the flow field on the valve stem the increase, resulting in more significant vibrations. Among these vibrations, the first three natural modes have the most substantial impact on the valve stem. To prevent damage to the valve stem, efforts should be made to minimize the influence of these first three modes on axial flow check valves. This study provides valuable recommendations and support for preventing damage to the valve stem in operational scenarios involving axial flow check valves.