Hydraulic flap valves have the same functions as a check valve, and are capable of closing and opening automatically to release the water, as well as prevent reverse flow conditions under its gravity and the pressure difference between the inside and outside surfaces of the door. The drainage valve features a great water control capability, high corrosion resistance and easy installation.

Hydraulic flap valves are widely used in drainage water pipes, sewage drain port and wastewater treatment projects. It allows no water flow back.

Specification
For drainage outlets with dimensions over 2m×2m, the hydraulic flap valve is the best option.

Structural Features
Jushen's hydraulic drain gate is designed to release wastewater and prevent anything from flowing back into the pipeline. Consisting of upper and bottom doors, the valve opens and closes under buoyant forces and the pressure difference between the interior and exterior of the door. We have also equipped the valve with a hydraulic buffer device to protect the valve seat from door impact when it closes.

Advantages
1. The door comes in a sealed cavity structure, with the weight proportion ranging from 1.05 to 1.2
2. Counterweight is unnecessary
3. The bottom portion of the door opens first when there is a water flow passing through, which will push the piston in the hydraulic device to the end and bring water into the cavity. The water flow pressure will then mix with the buoyancy in order to open the upper door.
4. When the valve closes, the upper door closes first, and the bottom part works to push the piston and drain the water out of the valve. By doing so, the valve seat will be subject to a much smaller impact when the door closes.

Installation Precautions
1. Before installing, weld the seat with embedded reinforcement and pour concrete on it
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 doors' weight proportion.
3. When installing several non-return valves at the same time, please ensure that each valve seat exactly matches each door.
4. Before installing the flap valve, please check whether the bolt connectors are loose during delivery and fix the loose 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 reinforcement.
8. A frame plate is mounted on the flap gate 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.

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