Check valves—also known as non-return valves, one-way valves, reflux valves, or isolation valves—are automatic valves that rely on the pressure of the medium itself and the weight of the valve disc to prevent backflow. Depending on the movement of the disc, they are categorized into types such as lift, swing, and butterfly. Lift-type check valves are structurally similar to globe valves but lack a valve stem, while swing-type check valves feature a disc that rotates around an axis.
