Analysis of the working principle of the ball type check valve

Ball check valves, also known as check valves or check valves, are designed to prevent backflow of media in the line. Generally, the ball type check valve is automatically opened and closed by the force generated by the flow of the medium itself in the pipeline, and belongs to an automatic valve. The ball type check valve is used in the piping system, and its main function is to prevent the medium from flowing backward, to prevent the pump and its driving motor from reversing, and to vent the medium in the container. The ball check valve can also be used to supply a line to an auxiliary system where the pressure may rise above the main system pressure. The ball type check valve can be applied to pipes of various media depending on the material. The ball type check valve is installed on the pipeline, which becomes one of the fluid components of the complete pipeline. The valve flap opening and closing process is affected by the transient flow state of the system in which it is located; in turn, the valve flap is closed. The characteristics in turn contribute to the fluid flow state. The working characteristic of the ball type check valve is that the load changes greatly, the opening and closing frequency is small, and when the input is closed or opened, the applicable period is long and the moving parts are not required to move. But once it is "switched", it must be flexible, which is more demanding than the usual mechanical movements. Since the ball check valve is qualitatively determined for quick closing in most practical applications, the medium is directional in the moment the ball check valve is closed, and the media is moving from the maximum back speed as the valve flap is closed. It quickly drops to zero, and the pressure rises rapidly, creating a "water hammer" that can damage the piping system. For high pressure piping systems where multiple pumps are used in parallel, the water hammer problem of the ball type check valve is more prominent. A water hammer is a pressure wave in a transient flow in a pressure pipe. It is a hydraulic shock phenomenon in which the pressure rises or falls due to a change in the fluid flow rate in the pressure pipe. The physical causes are the combined effects of fluid incompressibility, fluid motion inertia and pipe elasticity. In order to prevent the water hammer in the pipeline, people have adopted some new structures and new materials in the design of the ball check valve for many years. The impact force of the water hammer is ensured while ensuring the applicable performance of the ball check valve. Promising progress has been made in minimizing it.