Check valves, also known as check valves, single flow valves, one-way valves, or check valves, are designed to ensure the directional flow of media in the pipeline without backflow. The bottom valve of the water pump suction pipe also belongs to the category of check valves. Check valves belong to automatic valves and are used in pipelines under various working conditions such as petroleum, chemical, pharmaceutical, fertilizer, and power industries. They are suitable for media such as water, oil, steam, and acidic media.