Described herein is a floating flap gate including a gate leaf having a buoyancy forming portion, the gate leaf being configured to be raised due to buoyancy effect (e.g., from water), a bottom fitting mounted to a proximal end portion of the gate leaf, the bottom fitting having a convex circular arc-shaped surface across a width direction of the gate leaf, a plate member having a concave circular arc-shaped surface to be mated with the convex circular arc-shaped surface of the bottom fitting when the gate leaf is in a lowered state, wherein the concave circular arc-shaped surface is in contact with the convex circular arc-shaped surface when the gate leaf is raised.

Described herein is a floating flap gate including a gate leaf having a buoyancy forming portion, the gate leaf being configured to be raised due to buoyancy effect (e.g., from water), a bottom fitting mounted to a proximal end portion of the gate leaf, the bottom fitting having a convex circular arc-shaped surface across a width direction of the gate leaf, a plate member having a concave circular arc-shaped surface to be mated with the convex circular arc-shaped surface of the bottom fitting when the gate leaf is in a lowered state, wherein the concave circular arc-shaped surface is in contact with the convex circular arc-shaped surface when the gate leaf is raised.

A pressure-tight door allowing movement of hinges includes: a hinge fixating part including a fixed member having one surface with a movable groove formed therein and the other surface fixed to a door frame, and a movable member having one surface inserted into the movable groove so as to slide bidirectionally on the movable groove and a hinge attached to the other surface of the movable member, connected to a door and sliding together with the movable member. The movable member of the hinge fixating part slides inwardly together with the hinge only when the pressure due to flooding or explosion is applied to the pressure-tight door, whereby the pressure-tight door is able to effectively block any leakage by compressing the gasket.

A pressure-tight door allowing movement of hinges includes: a hinge fixating part including a fixed member having one surface with a movable groove formed therein and the other surface fixed to a door frame, and a movable member having one surface inserted into the movable groove so as to slide bidirectionally on the movable groove and a hinge attached to the other surface of the movable member, connected to a door and sliding together with the movable member. The movable member of the hinge fixating part slides inwardly together with the hinge only when the pressure due to flooding or explosion is applied to the pressure-tight door, whereby the pressure-tight door is able to effectively block any leakage by compressing the gasket.

An opening/closing device according to the present invention includes a gate, a fall prevention unit, a support release unit, a first float, a floating prevention unit, a second float, and a floating prevention release unit. The gate receives a flow of fluid, and is able to fall down toward a downstream direction of the flow. The fall prevention unit supports the gate, thereby preventing the gate from falling down. The support release unit releases the support for the gate by the fall prevention unit. The first float is arranged on an upstream side of the gate, is arranged on one of the left side and the right side of the gate viewed from upstream, and is less in the specific gravity than the fluid. The floating prevention unit prevents the first float from floating.

An opening/closing device according to the present invention includes a gate, a fall prevention unit, a support release unit, a first float, a floating prevention unit, a second float, and a floating prevention release unit. The gate receives a flow of fluid, and is able to fall down toward a downstream direction of the flow. The fall prevention unit supports the gate, thereby preventing the gate from falling down. The support release unit releases the support for the gate by the fall prevention unit. The first float is arranged on an upstream side of the gate, is arranged on one of the left side and the right side of the gate viewed from upstream, and is less in the specific gravity than the fluid. The floating prevention unit prevents the first float from floating.

A method for controlling the gate based on the habitat requirement for fish overwintering in rivers. According to the characteristics of biological habitat of the river and the habitat demand of fishes during overwintering, the method specifically comprises the steps of: firstly, determining candidate fishes for ecological flow calculation though fish resources investigating and historical data, and then screening out the target fish by adopting hierarchical analysis method; Secondly, establishing a quantitative response relationship curve between target fish physiological adaptions and water temperature, obtaining ecological water level which ensures the target fish overwintering safely according to the vertical temperature distribution, and establishing the relation between water depth and discharge using hydrodynamic model; finally, setting up a gate control system including a radar water level meter in the overwintering areas and an ecological water level management system in a gate control room.

A method for controlling the gate based on the habitat requirement for fish overwintering in rivers. According to the characteristics of biological habitat of the river and the habitat demand of fishes during overwintering, the method specifically comprises the steps of: firstly, determining candidate fishes for ecological flow calculation though fish resources investigating and historical data, and then screening out the target fish by adopting hierarchical analysis method; Secondly, establishing a quantitative response relationship curve between target fish physiological adaptions and water temperature, obtaining ecological water level which ensures the target fish overwintering safely according to the vertical temperature distribution, and establishing the relation between water depth and discharge using hydrodynamic model; finally, setting up a gate control system including a radar water level meter in the overwintering areas and an ecological water level management system in a gate control room.

A water conserving gate includes a base and a gate board configured to resist external water flow. A first supporting column, a second supporting column and a third supporting column are sequentially arranged on an upper portion of the base. A control box is arranged on the upper portion of the base. A first connecting rod is connected between a gate board and the first supporting column; a second connecting rod is connected between the gate board and the second supporting column. A third connecting rod is connected between the gate board and the third supporting column. A first rotary boss arranged on the first supporting column is movably connected with the first connecting rod. A second rotary boss arranged on the second supporting column is movably connected with the second connecting rod.

The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe aeration, hinges, and bladder manufacture technology are disclosed herein.