An NRV (Non Return Valve) is a valve that allows water or other fluids to flow in one direction only. As the name suggests, "Non Return" means the fluid cannot return or flow backward. When the flow stops or reverse pressure develops, the valve automatically closes, preventing backflow and protecting pumps, pipelines, and other equipment from damage. At Cair Euromatic Automation Pv... https://resilientgatevalve.com/product-category/non-return-valve-manufacturer/