The Swing Type Check Valve flap rotates around the rotating shaft, and its fluid resistance is generally smaller than that of the lifting check valve. It is suitable for large diameter applications, and the installation position is not limited. It is usually installed in a horizontal pipeline. Larger caliber occasions. According to the number of valve flaps, it can be divided into three types: single flap swing type, double flap swing type and multi-lobed swing type. Single-lobed Swing Type Check Valve are generally used with medium caliber. When the single-valve rotary check valve is used for the large-diameter pipeline, in order to reduce the water hammer pressure, it is preferable to use a slow-closing check valve that can reduce the water hammer pressure. The double-valve Swing Type Check Valve is suitable for large and medium diameter pipes. The double-grip Swing Type Check Valve has a small structure and light weight, and is a quick check valve; the multi-lobed Swing Type Check Valve is suitable for large diameter pipelines.