In the pipeline system, the check valve plays a vital role, which can effectively protect the pipeline and mechanical equipment from water hammer damage. As pipeline designers pay more and more attention to valve performance, indicators such as dynamic response characteristics, minimum full-open flow rate, water hammer effect and pressure drop have become key considerations when selecting. The axial flow check valve, with its simple structure, light weight, stable operation, long life and maintenance-free characteristics, just meets these requirements and becomes the ideal choice for the pipeline system.
Working principle of axial flow check valve
- The opening and closing of the axial flow check valve is controlled by the pressure difference between the inlet and outlet of the valve. The axial flow check valve automatically opens and closes by the pressure difference between the inlet and outlet, maintaining dynamic force balance to reduce water hammer and noise. When the inlet pressure exceeds the sum of the outlet pressure and the circulation expansion spring force, the valve disc will automatically open, and as long as the pressure difference continues to exist, the valve disc will remain in the open state, and its opening degree will change with the pressure difference. On the contrary, when the sum of the outlet pressure and the spring force is greater than the inlet pressure, the valve disc will close and remain closed. Since the opening and closing of the valve disc is in a dynamic force balance, the axial flow check valve runs smoothly, without noise, and significantly reduces water hammer.
- The pressure difference is the key factor to ensure that the valve is tightly closed, and the spring only provides a small reseating force. This design makes the spring extremely sensitive. Once the fluid starts to flow back, the valve disc can be immediately affected and quickly reseated, thus ensuring that the valve has a longer service life and avoids damage. In addition, the axial flow check valve adopts a smooth streamlined geometric design to minimize the pressure loss when the fluid passes through, while shortening the stroke. Its valve disc has a small mass, which reduces the friction on the guide surface and enables the valve disc to reseat quickly. This small mass, low inertia valve disc contacts the valve seat surface with a very small impact force after a short stroke, effectively preventing damage and leakage of the valve seat sealing surface.
- In axial flow check valves, the lowest V value is emphasized in the design. During the valve opening process, by testing the force acting on the valve disc, it can be found that as the opening angle increases, the force on the valve disc of the swing and inclined valve disc check valves gradually decreases, which is due to the reduction of the opening area. In the axial flow check valve, this problem is effectively solved. Optimizing the minimum flow rate can significantly reduce maintenance costs and improve the reliability of the check valve.