They are products used in pipelines to allow the liquid to flow in the direction of flow while preventing it from flowing in the opposite direction. In pumping plants, it prevents the liquid from flowing back in case the pump is deactivated. The valve is closed by its own weight or by counter force. Check valves should be installed by paying attention to the flow direction of the liquid. The maintenance of the system is done by opening the top cover and easily removing the flapper with swing system and installing a new one. Easily used in hot and cold water plants, drinking water networks and non-acidic fluids.