Movement 

The flap gate usually discharge the water by the pressure of drainage.

When the water level outside flap gate gets higher than water level of drainage,

the gate fits over open-mouth and prevent water back flow into drainage.

The advantages of using this gate compared with steel or stainless gate as below

 ♦Anticorrosive and easy to set up

 ♦Easy to open the gate because of light weight

  Installation 

The flap gate is set up on the wall with concrete anchor (refer to the picture below).

The wall should be flat and smooth so that the gate keeps high water tightness.

 We would not want to limit your idea and imagination.