Flap gate

A flap gate is a hydraulic facility that achieves automatic water level regulation through the balance of hydraulic force and self-weight, primarily used in reservoirs, rivers, and other locations to block or discharge water flow. Its core principle involves lever balance and rotation mechanisms, with structural components including panels, support legs, and piers, enabling automatic opening and closing to maintain a set water level range. ‌
Core Principle
The flap gate operates based on the moment balance principle between water pressure and gate weight: when the upstream water level rises, water pressure pushes the gate to rotate around the pivot point, opening to release flow; as the water level drops, the gate automatically closes to retain water, keeping the level within the set range. For instance, the roller-link mechanism utilizes dual-pivot linkages to achieve automatic regulation, avoiding vibration and slamming issues common in traditional gate operations. ‌