The side-hinged gate features a one-way opening and reverse-closing function. With the help of its self-weight balancing function, the gate's valve cover automatically opens or closes the gate leaf in response to water flow, or can be manually opened or closed with minimal force; the gate cover is equipped with a handle, and the opening angle of the handle cover should be greater than 60 degrees, ensuring smooth operation. When the gate section is submerged in water, the operation should be free and flexible.