Tap the door - mainly installed at the end of the drainage pipe to prevent external water from flowing back. According to the material, it can be divided into various materials such as stainless steel flap doors, cast iron flap doors, steel flap doors, composite material flap doors (fiberglass flap doors), etc.

And there are many types of flap doors, which can be divided into square flap doors and circular flap doors according to the shape of the pipeline opening. According to their form, they can be divided into floating box type flap doors, flat plate flap doors, sleeve flap doors, and so on

It is a one-way valve installed at the outlet of the drainage pipe and pump station by the river. When the tide level of the river is higher than the outlet pipe and the pressure is greater than the pressure inside the pipe, the flap panel automatically closes to prevent the river tide from flowing back into the drainage pipe. At present, door flaps are divided into suspended, single/double door, energy-saving and other models.