At time 0, filtered effluent was introduced to the 350 mm diameter pipe with duckbill at the end.
At time 36", water came out of the valve.
At time 1'40", feeding stopped.
At time 3'55", minimum water came out of the valve. The FE valve was re-opened.
At time 4'05", water came out of the valve.
At Time 4'30", the feed valve closed.
This video shows the water pass through the duckbill. It was installed in a horizontal position. The water will be first fill the lower half of the pipe then buildup head to go through the valve. When the inlet flow stops, the water gradually flow out of the valve.
Because the lower half pipe is filled with water, when the pipe is refilled, the water came out quickly. This demonstrates the duckbill need little head to open.
Anyway, the duckbill will be re-orientated to vertical position for better performance and no residual water in the pipe.
