Noisy Gurgling Overflow - SOLVED!!!!

[Ron99]

I actually have a reverse Durso at the bottom so air can escape. No back pressure in the line and it is not flushing or siphoning at all. It's not an air gurgling sound but a constant loud sound of the water flowing/rushing down the pipe. I do have an adjustable air valve in the cap at the top but changing that does nothing for the noise. It only changes the depth of water in the overflow box.

I have pretty much come to the conclusion that trying to run a single external Durso overflow from a bulkhead on the back of the tank near the top is extremely difficult and a poor choice. The best way to run overflows drilled at the top back of a tank is the herbie style. I am going to see if I can come up with a clever external herbie run off one bulkhead.

[golf nut]

It's rather difficult to solve a problem if we don't have all the facts, do you have pics?

[Ron99]

Hard to get pictures due to limited access but here's a diagram of how it is set up.

[golf nut]

are there any reductions in the drain, at what level of the display is the water compared to the centerline of the drain bulkhead.

[Ron99]

There were no reductions in the drain, all 1.5 inch pipe. The centerline of the bulkhead is probably around 4 inches below the level of water in the tank.

In any case, it is academic now as I have solved the problem. I built a pseudo Herbie overflow with 2 1" drains coming off the 1.5 inch bulkhead using a T. It's angled so the majority of the flow goes down one side of the T and I have a ball valve on it to control the flow a la Herbie overflow. The higher end of the T is the emergency drain and dips around via 2 90 degree fittings. It is virtually silent now. Yay!!!!

I'll try to post some pics later.

[Ron99]

Finally getting around to posting a pic of my solution. It is a sort of Herbie going from a single 1.5" bulkhead to two 1" lines. It is nearly silent now and a huge difference from the constant sound of rushing water coming from the Durso.