What is a tilting disc check valve?

The TDC valves refer to the tilting disc check valves which are designed to be used in applications where rapid response required. Or it can be said that the tilting disc check valves are expected to perform the fast opening or closing.
Generally speaking, the require the more exacting design and assembly technique than other types of check valves. For example, the hinge pin is located near the disc center of gravity, minimizing sealing surface radius rotation and thus velocity. And the reduced moment arm of the disc makes it imperative that the hinge pin bushings are properly aligned and non-binding to permit smooth swinging, as well as to maintain the precise geometry required for leak tightness