Check valves will prevent flow in one direction and facilitate flow in the opposite direction. Check valves are sometimes called non-return valves. Floating disk-style check valves have a disk that will change position inside of the body with the flow of media. In the forward direction, the media is able to flow around the disk. In the reverse direction, the disk is pushed against the seat and prevents flow. These check valves combine the benefits of a soft silicone seat with a hard floating disk: great sealing characteristics and high reverse pressure ratings.