Check valves are mechanical valves that permit gases and liquids to flow in only one direction, preventing process flow from reversing. They are classified as one-way directional valves and allow the water to flow in only one direction.. Water flow in the desired direction opens the valve, while backflow forces the valve closed. Our product range includes an impressive selection of automatic flow limiting (AFL) valves. AFL valve solutions can be used in hot and cold plumbing setups, and in clean chilled water systems for a/c fan coil units. As well as showers, they can feature in wash basins, baths, urinals, bidets, washing machines, toilets, dishwashers and a host of other applications.