A circular flap valve is usually mounted above the normal water level in a pipeline to prevent the water from flowing back. Functioning as a check valve, the liquid control device releases water and resets automatically under its own gravity and the pressure difference between the interior and exterior of the door. It features a powerful water cutoff capability, strong corrosion resistance, and is easy to mount.

How it Works
The circular flap valve is designed to release water flow out of the pipeline without allowing anything flowing back. It opens or closes using the buoyancy in the water and the pressure difference between the interior and exterior of the door

Specification of circular flap valve
Nominal pressure (PN): 0.25-1.6Mpa
Nominal diameter (DN): 350-2000mm。

Advantages of circular flap valve
1. The valve comes in a sealed cavity structure, with the weight proportion of door ranging from 1.05 to 1.2
2. Counterweight is unnecessary
3. Small impact upon the seat when the valve is closed

Installation Precautions
1. The flap gate can be connected with a flange and embedded.
2. For optimum performance, operators can inject water into the valve's sealed cavity or release a certain amount of water from the valve to change the door's weight proportion.
3. When installing several valves at the same time, please ensure that each valve seat precisely matches each door.
4. Before installing the flap valve, please check whether the bolt connectors are loose during delivery and fix the loosened parts.
5. Ensure that the valve seat and the door are on the same plane
6. In case of door deformation, the valve seat and the door should be installed as a whole rather than being mounted separately.
7. Before pouring the concrete for the second time, find the right installation location, and then weld the bolts with embedded reinforcements or connect the valve directly to the flange.
8. A frame plate is mounted on the drainage valve during the production to make sure the seat and door fit tightly. Therefore, remember to remove the frame plate from the drainage system so that the valve can open and close smoothly.
9. The mortar flowing into the seat, door, and baffle gap during the concrete pouring process should be removed completely to make sure the valve moves easily.

You may also find products like:
Wastewater Drainage Gates, Check Valve, Pipeline Control Device, Flap Gate, Pipe End Valve