Non-slam check valve is also called a one-way valve or check valve. Its function is to prevent the medium backflow in the pipeline. The bottom valve of the pump suction closure also belongs to the non slam check valve class. The non slam check valve is generally divided into lifting type, swing type, butterfly type, and diaphragm type. Lifting non-slam check valve is similar to a globe valve. Its disc moves reliably along the line of the passage, but the main force of the fluid is larger. It is suitable for smaller caliber occasions. The straight-through non-slam check valve can only be installed in the horizontal pipeline, while the vertical non-slam check valve is usually installed in the vertical pipeline. Piping. The rotary non-slam check valve disc rotates around the rotating axis, and its resistance is generally less than that of the lifting non-slam check valve. It is suitable for larger caliber applications. Butterfly non slam check valve is similar to a butterfly valve in structure, which has a simple structure and small flow resistance. Diaphragm non-slam check valve has many structural forms. The diaphragm is used as an opening and closing parts. Its waterproof hammer has good performance, simple structure, and low cost. However, the temperature and pressure of the diaphragm-type non-slam check valve are limited by the diaphragm material.