Dam GatesDam gate
Japan is blessed with an abundance of water, and the steepness of the landscape allows rainwater to flow easily from the mountains to the ocean.
Dams play an important role in maintaining river environments, as well as performing flood control (flood risk reduction) and irrigation (agriculture, power generation, water supply) functions.
With our extensive experience and latest technical capabilities, NISHIDA TEKKO provides dam gates across Japan.
- About Dam Gates
Dam gates are broadly categorized as flood control installations and irrigation installations (equipment for drawing in and discharging water for agricultural irrigation, towns and cities, and power generation). For this purpose, flood control installations are also equipped with regular discharge equipment (conduit, orifice) and emergency discharge equipment (crest), and irrigation installations with selective water intake equipment and irrigation discharge equipment.
Type of dam for gate equipment
Gate for the dam,in order to respond to the opening and closing method,a flow regulator and application,can be divided into the following types.
- Regular Discharge Equipment
This equipment regulates the flow of floodwater into the dam and discharges it. In general, it consists of a main gate + discharge pipe + reserve gate. A radial or roller gate is used for the main gate, and a roller gate used for the reserve gate. Equipment installed in deeper sections of the dam are known as conduits (planned depth of over 25 meter = high pressure), and equipment installed in shallower sections are known as orifices. In recent years, there has been an increasing number of “floodwater retention basins”, consisting of discharge pipes and lining, that allow floodwater to flow down naturally.
- Emergency Discharge Equipment
This equipment discharges water at times of unusual flooding, when the regular discharge equipment alone is insufficient, to maintain the security of the dam. In general, radial gates and roller gates are used.
- Irrigation Installations
(Selective Water Intake Equipment and Irrigation Discharge Equipment)
Selective water intake equipment are gates that can select and draw in water from any layer of the reservoir, for the purpose of drawing in warm water and improving water quality in dam lakes, and preserving downstream river environments. In general, linear multi-stage gates, circular multi-stage gates and perforated gates are used.
Irrigation discharge equipment regulates the flow rate of drawn-in water and discharges it. In general, it consists of a discharge pipe + secondary gate + main gate. A high-pressure slide gate is used for the secondary gate, and a jet flow gate or hollow jet valve is used for the main gate.