The invention discloses an overshot control gate for use with trapezoidal irrigation channels. A gate has a rigid rectangular section adapted to, in use, be pivotally mounted to a base of a trapezoidal irrigation channel. A pair of triangular sections are pivotally mounted on opposite sides of the rigid rectangular section. Each of the triangular sections are divided into first and second triangular sections with a common apex at the base of the trapezoidal irrigation channel. Each of the first triangular sections are rigid and adapted to, in use, be pivotally mounted to opposite side walls of the trapezoidal irrigation channel. Each of the second triangular sections including the pivotal mounting on opposite sides of the rigid rectangular section are formed of a flexible material. Also disclosed is a pipe flow meter and a duckbill valve.

The invention discloses an overshot control gate for use with trapezoidal irrigation channels. A gate has a rigid rectangular section adapted to, in use, be pivotally mounted to a base of a trapezoidal irrigation channel. A pair of triangular sections are pivotally mounted on opposite sides of the rigid rectangular section. Each of the triangular sections are divided into first and second triangular sections with a common apex at the base of the trapezoidal irrigation channel. Each of the first triangular sections are rigid and adapted to, in use, be pivotally mounted to opposite side walls of the trapezoidal irrigation channel. Each of the second triangular sections including the pivotal mounting on opposite sides of the rigid rectangular section are formed of a flexible material. Also disclosed is a pipe flow meter and a duckbill valve.

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.

An open breakwater dike system comprising a dike body, anchor feet, wherein the anchor feet are connected to or integral with a bottom surface of the dike body; and a first pillar connected to or integral with an upper surface of the dike body is disclosed. In an embodiment, the open dike system further comprises a second pillar connected to or integral with the upper surface of the dike body offset from the first pillar; a first flap gate rotationally attached to the first pillar and disposed between the first and second pillars, wherein the first flap gate closes against a first extension in the second pillar; and a means for opening and closing one or more flap gates, wherein the means for opening one or more flap gates opens and closes the first flap gate. A method of using the open breakwater dike system is also disclosed.

An open breakwater dike system comprising a dike body, anchor feet, wherein the anchor feet are connected to or integral with a bottom surface of the dike body; and a first pillar connected to or integral with an upper surface of the dike body is disclosed. In an embodiment, the open dike system further comprises a second pillar connected to or integral with the upper surface of the dike body offset from the first pillar; a first flap gate rotationally attached to the first pillar and disposed between the first and second pillars, wherein the first flap gate closes against a first extension in the second pillar; and a means for opening and closing one or more flap gates, wherein the means for opening one or more flap gates opens and closes the first flap gate. A method of using the open breakwater dike system is also disclosed.

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.

According to one embodiment, a flood vent includes a frame forming a fluid passageway through an opening in a structure. The flood vent further includes a door pivotally mounted to the frame in the fluid passageway for allowing a fluid to flow through the fluid passageway. The door has two opposing faces that include a first face and a second face. The flood vent further includes a first float positioned within the door in a location in-between the first face and a second float. Additionally, the first float is configured to allow the door to pivot in a first direction. The flood vent further includes the second float positioned within the door in a location in-between the second face and the first float. Furthermore, the second float is configured to allow the door to pivot in a second direction.

According to one embodiment, a flood vent includes a frame forming a fluid passageway through an opening in a structure. The flood vent further includes a door pivotally mounted to the frame in the fluid passageway for allowing a fluid to flow through the fluid passageway. The door has two opposing faces that include a first face and a second face. The flood vent further includes a first float positioned within the door in a location in-between the first face and a second float. Additionally, the first float is configured to allow the door to pivot in a first direction. The flood vent further includes the second float positioned within the door in a location in-between the second face and the first float. Furthermore, the second float is configured to allow the door to pivot in a second direction.

In order to achieve a swing motion type retractable floodgate using a cost-effective torsion structure, the present invention is provided with a swing pivot support mechanism, a friction shoe, a door bottom support seat, and an operation step during a tidal flow. The support mechanism allows free rotation about three axes and restricts motion in the three axis directions, and a pulling force acts on the support mechanism. The friction shoe dissipates tidal energy during closing operations in a tidal flow to a level that prevents damage to the door. Reactive forces are endured by reducing impact forces with the flexibility and strength of the door bottom support seat. Suitable tidal energy dissipation is performed by selecting friction force strength in the operation step.