Check valves are generally only used in pipelines or equipment to prevent backflow of media.
They permit fluid flow in only one direction while blocking flow in the opposite direction. Typically operating automatically, the valve disc opens under pressure from unidirectional fluid flow. When fluid flows in the opposite direction, the combined force of fluid pressure and the disc's own weight forces the disc against the seat, thereby shutting off flow. Suitable working media include water, steam, oil products, etc.
Check valves feature various configurations including swing, lift, and vertical types; sealing designs include soft-seal and hard-seal structures. They are commonly employed in power generation, petroleum refining, petrochemicals, offshore oil, municipal water supply systems, and chemical industries.
