The main disadvantages of the swing check valve are as follows:
Poor sealing performance: Under low-pressure conditions, the sealing performance of the swing check valve is usually not as good as that of the lift check valve. Because there may be a certain gap between the sealing surface of the valve disc and the valve seat when it is closed, it is difficult to achieve complete sealing, which is easy to cause medium leakage.
Large fluid resistance: Although the valve channel of the swing check valve is streamlined and the flow resistance is smaller than that of the straight-through lift check valve, the weight of the valve disc and the suspension of the valve disc in the fluid will cause turbulence in the fluid, so the fluid pressure drop through the swing check valve is greater than the pressure drop through other forms of check valves.
Obvious water hammer effect: When the flow direction changes suddenly, the valve disc will close violently on the valve seat, which will cause great wear of the valve seat and produce water hammer along the pipeline. Water hammer may cause damage to pipelines and equipment and affect the normal operation of the system.
High installation requirements: The installation position of the swing check valve needs to be correct to ensure that the valve disc can rotate smoothly. If improperly installed, the valve disc may not open or close flexibly, affecting the normal operation of the valve.
Complex structure: Compared with the lift check valve, the swing check valve has a more complex structure and a higher manufacturing cost. There are more parts such as the valve disc, rocker, and pin shaft inside, which require higher manufacturing precision and assembly requirements.
High requirements for the medium: The swing check valve is generally suitable for clean media, and is not suitable for media containing solid particles and high viscosity. Because these media may jam the valve disc or affect the sealing performance of the valve disc.