Hy-Grade Series D High Performance Dual Plate wafer swing check valves are designed for reliability and high-performance applications. The Series D differs from the most common dual plate check valves in its disk design. The disks swing out of the flow path, decreasing turbulence and pressure drops. This also allows the independent internal disk springs to be shielded from the flow path, creating instant sealing and non-slam operation. Additionally, the disks open within the internal valve body, preventing any interference with downstream piping or fittings. The disk is also comprised of an integrated flapper and pin, providing strength at a critical location. Typical swing check valve designs feature multiple components for the flapper assembly, including bushings, nuts, bolts, and hinge pins. These components wear out over time or come apart, leading to check valve failure.