When using a gated inlet for a siphon, what is a necessary feature?

Using a gated inlet for a siphon requires the presence of an external air bleeder to ensure the proper functioning of the system. The external air bleeder is essential because it allows air to escape from the siphon line as water fills it. If air is trapped in the line, it can create a vacuum that disrupts the siphon action, leading to inefficiency or complete failure of the siphon. This feature ensures that the water can flow smoothly without interruptions caused by air pockets.

In the context of siphoning, the ability to remove air is crucial for maintaining a continuous flow, especially in situations where the elevation change and the configuration of the line can lead to air entrapment. Therefore, incorporating an external air bleeder in the design of a gated inlet greatly enhances the effectiveness of the siphoning system.