Abstract: A fluid control system to control fluid flow within a drainage system is disclosed that includes a cage configured to couple an interior wall of a structure of the drainage system, wherein the cage at least partially surrounds an aperture of the interior wall, and a float device configured to be encapsulated within the cage, wherein while in a resting state, the float device at least partially covers an aperture of the structure of the drainage system. In some instances, when fluid contacts the float device at a flow rate of at least a flow threshold, the float device is configured to at least partially uncover the aperture of the interior wall, or further uncover the aperture of the interior wall. The float device may be formed from a buoyant material and configured to rise from the resting state in accordance with a rising fluid level within the structure.

Abstract: A fluid control system to control fluid flow within a drainage system is provided that includes a fluid control device configured to couple to an interior wall of a cylindrical structure of the drainage, and a coupling mechanism configured to couple the fluid control device to the interior wall, wherein, while in a resting state, the fluid control device is configured to at least partially cover an aperture of the interior wall. When fluid contacts the fluid control device at a flow rate of at least a flow threshold, the fluid control device is configured to at least partially uncover the aperture of the interior wall. The fluid control device has a spherical shape, wherein a diameter of the fluid control device has a diameter that is greater than or equal to a diameter of the aperture.

Abstract: A fluid control system to control fluid flow within a drainage system is provided that includes a fluid control device configured to couple to an interior wall of a cylindrical structure of the drainage, and a coupling mechanism configured to couple the fluid control device to the interior wall, wherein, while in a resting state, the fluid control device is configured to at least partially cover an aperture of the interior wall. When fluid contacts the fluid control device at a flow rate of at least a flow threshold, the fluid control device is configured to at least partially uncover the aperture of the interior wall. The fluid control device has a spherical shape, wherein a diameter of the fluid control device has a diameter that is greater than or equal to a diameter of the aperture.

Abstract: Single-door flap gates and double-door flap gates are disclosed. A first flap gate includes a first door coupled with a first hinge, a second door coupled with a second hinge, wherein the first door and the second door together form a continuous concave surface, wherein the first hinge and the second hinge couple with a wall, and wherein, when in a closed position, the first door and the second door rest against the wall to cover an opening thereof. The opening may correspond to an end of a pipe that extends away from the first door and the second door. Further, the continuous concave surface may include a radius of curvature configured to be substantially similar to a radius of curvature of the wall, wherein the wall may be interior wall of a cylindrical structure.

Abstract: Single-door flap gates and double-door flap gates are disclosed. Flap gates of the inventive subject matter are coupled with a structural element by one or more linkages, where hinges that are coupled with the structural element allow flap gate doors to open when sufficient fluid build-up exists behind the doors to push the doors open. Hinges are mounted at an angle. Features to facilitate fluid drainage despite the flap gate doors being closed are also contemplated.