Question about U tube type Overflows

You just identified the problem. You can now solve it by lengthening your standpipe, or your U-Tube.

 

Nope. Iis a U not a J LOL

 

Right, but all U-Tubes are a little longer on one side than the other. Otherwise the water wouldn't do anything, it would just sit there. With one side being longer, the water flows over and down the longer side.

So it matters which side of the box you have the longer side in.

 

And as such, that's why I said from a physics standpoint my question didn't make sense but I figured it was worth a shot.

 

Well I guess it on side is longer but not by much. Neither side passes the standpipe.

 

Not true, Brandon. The siphon doesn't depend on the U-Tube being longer on one side. It depends on the height difference between the two bodies of water.

Nearly every U-Tube I had back in the day was a U, not a J, although I have seen the J's too.

 

Well, every U-Tube *I* have seen is longer on one side. So I just assumed it was that way for all of them. The water level is consistently lower in the box inside the tank, for me anyways. So it makes sense that since the tube is longer on the other side that that's why the water flows that way instead of backwards.

 

While we're at it, Mission's post brings up a great point. The aqualifter model only works in instances where the overflow is set up properly--where the U-Tube extends down beyond the top of the standpipe in the external box. In circumstances where bubbles collect over time, eventually breaking the siphon, the aqualifter will remedy this ONLY because there is standing water both boxes of the overflow. As soon as this is not the case, the aqualifter would simply suck air until the end of time. Think of it like trying to drink through a straw that has a hole in it. Ain't gonna happen.

This is a caution those that think the aqualifter is a remedy for an improperly set up overflow. It is not.

 

*I* guessed that was the case.

 

LoL! At any rate we agree that the problem is because the tube doesn't go past the standpipe.

What I want to know is how the flow got started in the first place? Even if both sides were the same, wouldn't the tube on the drain side need to go past the standpipe regardless?